WO2016038744A1

WO2016038744A1 - Method for manufacturing semiconductor device, substrate processing apparatus and recording medium

Info

Publication number: WO2016038744A1
Application number: PCT/JP2014/074314
Authority: WO
Inventors: 敦佐野; 義朗 ▲ひろせ▼
Original assignee: 株式会社日立国際電気
Priority date: 2014-09-12
Filing date: 2014-09-12
Publication date: 2016-03-17

Abstract

This method for manufacturing a semiconductor device comprises a step for forming a film, which has a borazine ring skeleton and contains a specific element, boron and nitrogen, on a substrate by performing a cycle, which comprises a step for supplying a starting material gas containing the specific element and a halogen element to the substrate, a step for supplying a first boron-containing gas that contains a borazine ring skeleton to the substrate and a step for supplying a second boron-containing gas that does not contain a borazine ring skeleton to the substrate, several times under such conditions where the borazine ring skeleton in the first boron-containing gas is maintained.

Description

Semiconductor device manufacturing method, substrate processing apparatus, and recording medium

The present invention relates to a semiconductor device manufacturing method, a substrate processing apparatus, and a recording medium.

As a process of manufacturing a semiconductor device (device), a film having a borazine ring skeleton on a substrate and containing a predetermined element such as silicon (Si), boron (B), and nitrogen (N) (hereinafter referred to as borazine) A step of forming a boron nitride film including a ring skeleton may be performed.

An object of the present invention is to provide a technique capable of improving the controllability of the composition ratio of a boron nitride film containing a borazine ring skeleton.

According to one aspect of the invention,
Supplying a source gas containing a predetermined element and a halogen element to the substrate;
Supplying a first boron-containing gas containing a borazine ring skeleton to the substrate;
Supplying a second boron-containing gas not containing a borazine ring skeleton to the substrate;
Is performed a predetermined number of times under the condition that the borazine ring skeleton in the first boron-containing gas is retained, so that the substrate has the borazine ring skeleton, and the predetermined element, boron, and nitrogen There is provided a method for manufacturing a semiconductor device, which includes a step of forming a film including the same.

According to the present invention, it is possible to improve the controllability of the composition ratio of a boronitride film containing a borazine ring skeleton.

It is a schematic block diagram of the vertical processing furnace of the substrate processing apparatus used suitably by embodiment of this invention, and is a figure which shows a processing furnace part with a longitudinal cross-sectional view. FIG. 2 is a schematic configuration diagram of a part of a vertical processing furnace of a substrate processing apparatus suitably used in an embodiment of the present invention, and is a diagram showing a part of the processing furnace as a cross-sectional view taken along line AA of FIG. It is a schematic block diagram of the controller of the substrate processing apparatus used suitably by embodiment of this invention, and is a figure which shows the control system of a controller with a block diagram. It is a figure which shows the timing of the gas supply in the film-forming sequence of one Embodiment of this invention. It is a figure which shows the timing of the gas supply in the modification 4 of the film-forming sequence of one Embodiment of this invention. It is a figure which shows the timing of the gas supply in the modification 8 of the film-forming sequence of one Embodiment of this invention. It is a figure which shows the timing of the gas supply in the modification 9 of the film-forming sequence of one Embodiment of this invention. (A) is a chemical structural formula of HCDS, (b) is a diagram showing a chemical structural formula of OCTS. (A) is a chemical structural formula of BTCSM, (b) is a figure which shows the chemical structural formula of BTCSE. (A) is a chemical structural formula of TCDMDS, (b) is a chemical structural formula of DCTMDS, (c) is a figure which shows a chemical structural formula of MCPMDS. (A) is the chemical structural formula of borazine, (b) is the chemical structural formula of the borazine compound, (c) is the chemical structural formula of n, n ′, n ″ -trimethylborazine, and (d) is the n, n FIG. 2 is a diagram showing a chemical structural formula of ', n ″ -tri-n-propylborazine. (A) is a schematic block diagram of the processing furnace of the substrate processing apparatus used suitably by other embodiment of this invention, and is a figure which shows a processing furnace part with a longitudinal cross-sectional view, (b) is other of this invention It is a schematic block diagram of the processing furnace of the substrate processing apparatus used suitably by this embodiment, and is a figure which shows a processing furnace part with a longitudinal cross-sectional view.

<One Embodiment of the Present Invention>
Hereinafter, an embodiment of the present invention will be described with reference to FIGS.

(1) Configuration of Substrate Processing Apparatus As shown in FIG. 1, the processing furnace 202 has a heater 207 as heating means (heating mechanism). The heater 207 has a cylindrical shape and is vertically installed by being supported by a heater base (not shown) as a holding plate. As will be described later, the heater 207 also functions as an activation mechanism (excitation unit) that activates (excites) gas with heat.

Inside the heater 207, a reaction tube 203 constituting a reaction vessel (processing vessel) concentrically with the heater 207 is disposed. The reaction tube 203 is made of a heat-resistant material such as quartz (SiO ₂ ) or silicon carbide (SiC), and is formed in a cylindrical shape with the upper end closed and the lower end opened. A processing chamber 201 is formed in the cylindrical hollow portion of the reaction tube 203. The processing chamber 201 is configured to be able to accommodate wafers 200 as substrates in a state where they are aligned in multiple stages in a vertical posture in a horizontal posture by a boat 217 described later.

In the processing chamber 201,

nozzles

249 a and 249 b are provided so as to penetrate the lower side wall of the reaction tube 203. The

nozzles

249a and 249b are made of a heat resistant material such as quartz or SiC.

Gas supply pipes

232a and 232b are connected to the

nozzles

249a and 249b, respectively. As described above, the reaction tube 203 is provided with the two

nozzles

249a and 249b and the two

gas supply tubes

232a and 232b, and can supply a plurality of types of gases into the processing chamber 201. It has become.

However, the processing furnace 202 of this embodiment is not limited to the above-mentioned form. For example, a metal manifold that supports the reaction tube 203 may be provided below the reaction tube 203, and each nozzle may be provided so as to penetrate the side wall of the manifold. In this case, an exhaust pipe 231 described later may be further provided in the manifold. Even in this case, the exhaust pipe 231 may be provided below the reaction pipe 203 instead of the manifold. As described above, the furnace port of the processing furnace 202 may be made of metal, and a nozzle or the like may be attached to the metal furnace port.

The

gas supply pipes

232a and 232b are provided with mass flow controllers (MFC) 241a and 241b as flow rate controllers (flow rate control units) and

valves

243a and 243b as opening / closing valves, respectively, in order from the upstream direction.

Gas supply pipes

232c and 232d for supplying an inert gas are connected to the

gas supply pipes

232a and 232b on the downstream side of the

valves

243a and 243b, respectively. The

gas supply pipes

232c and 232d are provided with

MFCs

241c and 241d as flow rate controllers (flow rate control units) and

valves

243c and 243d as opening / closing valves, respectively, in order from the upstream direction.

A nozzle 249a is connected to the tip of the gas supply pipe 232a. As shown in FIG. 2, the nozzle 249 a is arranged in an annular space between the inner wall of the reaction tube 203 and the wafer 200, and extends upward from the lower portion of the inner wall of the reaction tube 203 in the arrangement direction of the wafer 200. To stand up. That is, the nozzle 249a is provided on the side of the wafer arrangement area where the wafers 200 are arranged, in an area that horizontally surrounds the wafer arrangement area, along the wafer arrangement area. That is, the nozzle 249 a is provided on the side of the end portion (peripheral portion) of the wafer 200 carried into the processing chamber 201 and perpendicular to the surface (flat surface) of the wafer 200. The nozzle 249a is configured as an L-shaped long nozzle, and a horizontal portion thereof is provided so as to penetrate the lower side wall of the reaction tube 203, and a vertical portion thereof is at least from one end side to the other end of the wafer arrangement region. It is provided to stand up to the side. A gas supply hole 250a for supplying gas is provided on the side surface of the nozzle 249a. The gas supply hole 250 a is opened so as to face the center of the reaction tube 203, and gas can be supplied toward the wafer 200. A plurality of gas supply holes 250a are provided from the lower part to the upper part of the reaction tube 203, each having the same opening area, and further provided at the same opening pitch.

A nozzle 249b is connected to the tip of the gas supply pipe 232b. The nozzle 249 b is provided in the buffer chamber 237. The buffer chamber 237 also functions as a gas dispersion space. The buffer chamber 237 is provided in an annular space between the inner wall of the reaction tube 203 and the wafer 200 and in a portion extending from the lower portion to the upper portion of the inner wall of the reaction tube 203 along the arrangement direction of the wafers 200. That is, the buffer chamber 237 is provided on the side of the wafer arrangement area, in a region that horizontally surrounds the wafer arrangement area, along the wafer arrangement area. That is, the buffer chamber 237 is provided on the side of the end portion of the wafer 200 loaded into the processing chamber 201. A gas supply hole 250 c for supplying a gas is provided at the end of the wall of the buffer chamber 237 adjacent to the wafer 200. The gas supply hole 250 c is opened so as to face the center of the reaction tube 203, and gas can be supplied toward the wafer 200. A plurality of gas supply holes 250c are provided from the lower part to the upper part of the reaction tube 203, each having the same opening area, and further provided at the same opening pitch.

The nozzle 249 b rises upward from the lower end of the inner wall of the reaction tube 203 toward the upper side in the arrangement direction of the wafer 200 at the end opposite to the end where the gas supply hole 250 c of the buffer chamber 237 is provided. Is provided. That is, the nozzle 249b is provided along the wafer arrangement region in a region that horizontally surrounds the wafer arrangement region on the side of the wafer arrangement region where the wafers 200 are arranged. That is, the nozzle 249 b is provided on the side of the end of the wafer 200 carried into the processing chamber 201 and perpendicular to the surface of the wafer 200. The nozzle 249b is configured as an L-shaped long nozzle, and its horizontal portion is provided so as to penetrate the lower side wall of the reaction tube 203, and its vertical portion is at least from one end side to the other end side of the wafer arrangement region. It is provided to stand up toward. A gas supply hole 250b for supplying gas is provided on the side surface of the nozzle 249b. The gas supply hole 250 b is opened to face the center of the buffer chamber 237. Similar to the gas supply hole 250c, a plurality of gas supply holes 250b are provided from the lower part to the upper part of the reaction tube 203. When the differential pressure between the buffer chamber 237 and the processing chamber 201 is small, the opening area and the opening pitch of the plurality of gas supply holes 250b may be the same from the upstream side (lower part) to the downstream side (upper part). Further, when the differential pressure between the buffer chamber 237 and the processing chamber 201 is large, the opening area of the gas supply holes 250b is gradually increased from the upstream side to the downstream side, or the opening pitch of the gas supply holes 250b is increased upstream. It is good to make it gradually smaller from the side toward the downstream side.

By adjusting the opening area and the opening pitch of each gas supply hole 250b from the upstream side to the downstream side as described above, the flow rate is almost the same from each of the gas supply holes 250b, although there is a difference in flow velocity. A certain gas can be ejected. Then, once the gas ejected from each of the plurality of gas supply holes 250b is introduced into the buffer chamber 237, the difference in gas flow velocity can be made uniform in the buffer chamber 237. The gas ejected into the buffer chamber 237 from each of the plurality of gas supply holes 250b is ejected into the processing chamber 201 from the plurality of gas supply holes 250c after the particle velocity of each gas is reduced in the buffer chamber 237. The gas ejected into the buffer chamber 237 from each of the plurality of gas supply holes 250b becomes a gas having a uniform flow rate and flow velocity when ejected into the processing chamber 201 from each of the gas supply holes 250c.

As described above, in the present embodiment, an annular vertically long space defined by the inner wall of the side wall of the reaction tube 203 and the ends (peripheries) of the plurality of wafers 200 arranged in the reaction tube 203. The gas is conveyed through the

nozzles

249a and 249b and the buffer chamber 237 disposed in the inner space, that is, in the cylindrical space. Then, gas is first ejected into the reaction tube 203 from the gas supply holes 250 a to 250 c opened in the

nozzles

249 a and 249 b and the buffer chamber 237, respectively, in the vicinity of the wafer 200. The main flow of gas in the reaction tube 203 is a direction parallel to the surface of the wafer 200, that is, a horizontal direction. With such a configuration, it is possible to supply gas uniformly to each wafer 200 and improve the film thickness uniformity of the thin film formed on each wafer 200. The gas flowing on the surface of the wafer 200, that is, the residual gas after the reaction, flows toward the exhaust port, that is, the direction of the exhaust pipe 231 described later. However, the direction of the remaining gas flow is appropriately specified depending on the position of the exhaust port, and is not limited to the vertical direction.

From the gas supply pipe 232a, for example, a halosilane source gas containing Si and a halogen element as a predetermined element is supplied into the processing chamber 201 through the MFC 241a, a valve 243a, and a nozzle 249a as a source gas having the predetermined element. .

The halosilane raw material gas is a halosilane raw material in a gaseous state, for example, a gas obtained by vaporizing a halosilane raw material in a liquid state at normal temperature and normal pressure, a halosilane raw material in a gaseous state at normal temperature and normal pressure, or the like. The halosilane raw material is a silane raw material having a halogen group. The halogen group includes chloro group, fluoro group, bromo group, iodo group and the like. That is, the halogen group includes halogen elements such as chlorine (Cl), fluorine (F), bromine (Br), iodine (I) and the like. It can be said that the halosilane raw material is a kind of halide. In the present specification, when the term “raw material” is used, it means “a liquid raw material in a liquid state”, “a raw material gas in a gaseous state”, or both. is there.

As the halosilane source gas, for example, a source gas containing Si and Cl and not containing C, that is, an inorganic chlorosilane source gas can be used. As the inorganic chlorosilane source gas, for example, hexachlorodisilane (Si ₂ Cl ₆ , abbreviation: HCDS) gas, octachlorotrisilane (Si ₃ Cl ₈ , abbreviation: OCTS) gas, or the like can be used. FIG. 8A shows the chemical structural formula of HCDS, and FIG. 8B shows the chemical structural formula of OCTS. It can be said that these gases are source gases containing at least two Si in one molecule, further containing Cl, and having a Si—Si bond. These gases act as Si sources in the substrate processing step described later.

As the halosilane source gas, for example, a source gas containing Si, Cl and an alkylene group and having a Si—C bond, that is, an alkylene chlorosilane source gas which is an organic chlorosilane source gas can be used. The alkylene group includes a methylene group, an ethylene group, a propylene group, a butylene group and the like. The alkylene chlorosilane source gas can also be referred to as an alkylene halosilane source gas. Examples of the alkylene chlorosilane source gas include bis (trichlorosilyl) methane ((SiCl ₃ ) ₂ CH ₂ , abbreviation: BTCSM) gas, ethylene bis (trichlorosilane) gas, that is, 1,2-bis (trichlorosilyl) ethane. ((SiCl ₃ ) ₂ C ₂ H ₄ , abbreviation: BTCSE) gas or the like can be used. 9A shows the chemical structural formula of BTCSM gas, and FIG. 9B shows the chemical structural formula of BTCSE. It can be said that these gases are source gases containing at least two Si in one molecule, further containing C and Cl, and having a Si—C bond. These gases act as a Si source and also as a C source in a substrate processing step to be described later.

As the halosilane source gas, for example, a source gas containing Si, Cl and an alkyl group and having a Si—C bond, that is, an alkylchlorosilane source gas which is an organic chlorosilane source gas can be used. Alkyl groups include methyl, ethyl, propyl, butyl and the like. The alkylchlorosilane source gas can also be referred to as an alkylhalosilane source gas. Examples of the alkylchlorosilane source gas include 1,1,2,2-tetrachloro-1,2-dimethyldisilane ((CH ₃ ) ₂ Si ₂ Cl ₄ , abbreviation: TCMDDS) gas, 1,2-dichloro-1 , 1,2,2-tetramethyldisilane ((CH ₃ ) ₄ Si ₂ Cl ₂ , abbreviation: DCTMDS) gas, 1-monochloro-1,1,2,2,2-pentamethyldisilane ((CH ₃ ) ₅ Si ₂ Cl (abbreviation: MCPMDS) gas or the like can be used. FIG. 10A shows a chemical structural formula of TCDMDS, FIG. 10B shows a chemical structural formula of DCTMDS, and FIG. 10C shows a chemical structural formula of MCPMDS. It can be said that these gases are source gases containing at least two Si in one molecule, further containing C and Cl, and having a Si—C bond. These gases act as a Si source and also as a C source in a substrate processing step to be described later.

When using a liquid material that is in a liquid state at normal temperature and pressure, such as HCDS, BTCSM, or TCDMDS, the raw material in the liquid state is vaporized by a vaporization system such as a vaporizer or bubbler, and the raw material gas (HCDS gas, BTCSM gas) , TCDMDS gas).

Further, from the gas supply pipe 232b, as a reaction gas having a chemical structure (molecular structure) different from that of the source gas, for example, a gas containing a borazine ring skeleton as the first boron (B) -containing gas is used as the MFC 241b and the valve 243b. , And supplied into the processing chamber 201 through the nozzle 249 b and the buffer chamber 237. As the gas containing a borazine ring skeleton, for example, a gas containing a borazine ring skeleton and an organic ligand, that is, an organic borazine-based gas can be used.

As the organic borazine-based gas, for example, a gas obtained by vaporizing an alkyl borazine compound that is an organic borazine compound can be used. The organic borazine-based gas can also be referred to as a borazine compound gas or a borazine-based gas.

Here, borazine is a heterocyclic compound composed of three elements of B, N and H, and the composition formula can be represented by B ₃ H ₆ N ₃ , and the chemical structure shown in FIG. It can be expressed by a formula. A borazine compound is a compound containing a borazine ring skeleton (also referred to as a borazine skeleton) that constitutes a borazine ring composed of three Bs and three Ns. The organic borazine compound is a borazine compound containing C, and can be said to be a ligand containing C, that is, a borazine compound containing an organic ligand. The alkyl borazine compound is a borazine compound containing an alkyl group, and can be said to be a borazine compound containing an alkyl group as an organic ligand. The alkyl borazine compound is obtained by substituting at least one of six H contained in borazine with a hydrocarbon containing one or more C, and can be represented by a chemical structural formula shown in FIG. . Here, R ₁ to R ₆ in the chemical structural formula shown in FIG. 11B are H or an alkyl group containing 1 to 4 C. R ₁ to R ₆ may be the same type of alkyl group or different types of alkyl groups. However, the case where R ₁ to R ₆ are all H is excluded. The alkyl borazine compound has a borazine ring skeleton constituting a borazine ring and can be said to be a substance containing B, N, H and C. An alkyl borazine compound can also be said to be a substance having a borazine ring skeleton and containing an alkyl ligand. R ₁ to R ₆ may be H, or an alkenyl group or alkynyl group containing 1 to 4 C atoms. R ₁ to R ₆ may be the same type of alkenyl group or alkynyl group, or may be a different type of alkenyl group or alkynyl group. However, the case where R ₁ to R ₆ are all H is excluded.

The borazine-based gas acts as a B source, an N source, and a C source in a substrate processing step described later.

Examples of the borazine-based gas include n, n ′, n ″ -trimethylborazine (abbreviation: TMB) gas, n, n ′, n ″ -triethylborazine (abbreviation: TEB) gas, n, n ′, n ″ — Tri-n-propylborazine (abbreviation: TPB) gas, n, n ′, n ″ -triisopropylborazine (abbreviation: TIPB) gas, n, n ′, n ″ -tri-n-butylborazine (abbreviation: TBB) Gas, n, n ′, n ″ -triisobutylborazine (abbreviation: TIBB) gas, or the like can be used. In TMB, R ₁ , R ₃ , and R ₅ in the chemical structural formula shown in FIG. 11B are H, and R ₂ , R ₄ , and R ₆ are methyl groups, and the chemistry shown in FIG. It is a borazine compound that can be represented by a structural formula. TEB is a borazine compound in which R ₁ , R ₃ , and R ₅ in the chemical structural formula shown in FIG. 11B are H, and R ₂ , R ₄ , and R ₆ are ethyl groups. In TPB, R ₁ , R ₃ , and R ₅ in the chemical structural formula shown in FIG. 11B are H, and R ₂ , R ₄ , and R ₆ are propyl groups, and the chemistry shown in FIG. It is a borazine compound that can be represented by a structural formula. TIPB is a borazine compound in which R ₁ , R ₃ , and R ₅ in the chemical structural formula shown in FIG. 11B are H, and R ₂ , R ₄ , and R ₆ are isopropyl groups. TBB is a borazine compound in which R ₁ , R ₃ , and R ₅ in the chemical structural formula shown in FIG. 11B are H, and R ₂ , R ₄ , and R ₆ are butyl groups. TIBB is a borazine compound in which R ₁ , R ₃ , and R ₅ in the chemical structural formula shown in FIG. 11B are H, and R ₂ , R ₄ , and R ₆ are isobutyl groups.

When using a borazine compound that is in a liquid state at normal temperature and pressure, such as TMB, the borazine compound in a liquid state is vaporized by a vaporization system such as a vaporizer or bubbler and supplied as a borazine-based gas (TMB gas or the like). It will be.

Further, from the gas supply pipe 232b, for example, a B-containing gas not containing a borazine ring skeleton as the second boron (B) -containing gas is used as a reactive gas having a chemical structure different from that of the source gas, such as an MFC 241b, a valve 243b, It is supplied into the processing chamber 201 through the nozzle 249 b and the buffer chamber 237. As the B-containing gas not containing a borazine ring skeleton, for example, a borane-based gas can be used.

The borane-based gas is a gas obtained by vaporizing a borane compound in a gaseous state, for example, a borane compound in a liquid state at normal temperature and normal pressure, a borane compound in a gas state at normal temperature and normal pressure, or the like. The borane compound includes a haloborane compound containing B and a halogen element, for example, a chloroborane compound containing B and Cl. In addition, borane compounds include boranes (borohydrides) such as monoborane (BH ₃ ) and diborane (B ₂ H ₆ ), and borane compounds in which borane H is substituted with other elements (borane derivatives). Is included. The borane-based gas acts as a B source in the substrate processing step described later. As the borane-based gas, for example, trichloroborane (BCl ₃ ) gas can be used. The BCl ₃ gas is a B-containing gas that does not contain a borazine compound described later, that is, a non-borazine-based B-containing gas.

Further, from the gas supply pipe 232b, for example, a nitrogen (N) -containing gas as a reactive gas having a chemical structure different from that of the raw material gas enters the processing chamber 201 through the MFC 241b, the valve 243b, the nozzle 249b, and the buffer chamber 237. Supplied. As the N-containing gas, for example, a hydrogen nitride-based gas can be used. The hydrogen nitride-based gas can be said to be a substance composed of only two elements of N and H, and acts as a nitriding gas, that is, an N source, in a substrate processing step described later. As the hydrogen nitride-based gas, for example, ammonia (NH ₃ ) gas can be used.

Further, from the gas supply pipe 232b, for example, a carbon (C) -containing gas as a reaction gas having a chemical structure different from that of the raw material gas enters the processing chamber 201 through the MFC 241b, the valve 243b, the nozzle 249b, and the buffer chamber 237. Supplied. As the C-containing gas, for example, a hydrocarbon-based gas can be used. The hydrocarbon-based gas can be said to be a substance composed of only two elements of C and H, and acts as a C source in the substrate processing step described later. As the hydrocarbon-based gas, for example, propylene (C ₃ H ₆ ) gas can be used.

From the

gas supply pipes

232c and 232d, as an inert gas, for example, nitrogen (N ₂ ) gas passes through

MFCs

241c and 241d,

valves

243c and 243d,

gas supply pipes

232a and 232b,

nozzles

249a and 249b, and a buffer chamber 237, respectively. And supplied into the processing chamber 201.

When supplying the source gas from the gas supply pipe 232a, the source gas supply system is mainly configured by the gas supply pipe 232a, the MFC 241a, and the valve 243a. The nozzle 249a may be included in the source gas supply system. The source gas supply system can also be referred to as a source supply system. When the halosilane source gas is supplied from the gas supply pipe 232a, the source gas supply system may be referred to as a halosilane source gas supply system or a halosilane source supply system.

When supplying the first B-containing gas from the gas supply pipe 232b, the first B-containing gas supply system is mainly configured by the gas supply pipe 232b, the MFC 241b, and the valve 243b. The nozzle 249b and the buffer chamber 237 may be included in the first B-containing gas supply system. When supplying a borazine-based gas as the first B-containing gas from the gas supply pipe 232b, the first B-containing gas supply system may be a borazine-based gas supply system, an organic borazine-based gas supply system, or a borazine compound supply system. It can also be called. Since the borazine-based gas is a gas containing N and C, is also an N-containing gas, and is a C-containing gas, the borazine-based gas supply system is changed to an N-containing gas supply system and a C-containing gas supply system, which will be described later. It can also be considered.

When supplying the second B-containing gas from the gas supply pipe 232b, the second B-containing gas supply system is mainly configured by the gas supply pipe 232b, the MFC 241b, and the valve 243b. The nozzle 249b and the buffer chamber 237 may be included in the second B-containing gas supply system. When the borane-based gas is supplied as the second B-containing gas from the gas supply pipe 232b, the second B-containing gas supply system may be referred to as a borane-based gas supply system or a borane compound supply system.

When supplying N-containing gas from the gas supply pipe 232b, an N-containing gas supply system is mainly configured by the gas supply pipe 232b, the MFC 241b, and the valve 243b. The nozzle 249b and the buffer chamber 237 may be included in the N-containing gas supply system. The N-containing gas supply system can also be referred to as a nitriding gas supply system or a nitriding agent supply system. When supplying a hydrogen nitride-based gas from the gas supply pipe 232b, the N-containing gas supply system may be referred to as a hydrogen nitride-based gas supply system or a hydrogen nitride supply system.

When supplying the C-containing gas from the gas supply system 232b, the C-containing gas supply system is mainly configured by the gas supply pipe 232b, the MFC 241b, and the valve 243b. The nozzle 249b and the buffer chamber 237 may be included in the C-containing gas supply system. When the hydrocarbon-based gas is supplied from the gas supply pipe 232b, the C-containing gas supply system can also be referred to as a hydrocarbon-based gas supply system or a hydrocarbon supply system.

Any one or both of the first B-containing gas supply system and the second B-containing gas supply system described above may be referred to as a B-containing gas supply system. In addition, any or all of the above-described B-containing gas supply system, N-containing gas supply system, and C-containing gas supply system may be referred to as a reaction gas supply system or a reactant supply system. it can.

Further, an inert gas supply system is mainly configured by the

gas supply pipes

232c and 232d, the MFCs 241c and 241d, and the

valves

243c and 243d. The inert gas supply system can also be referred to as a purge gas supply system, a dilution gas supply system, or a carrier gas supply system.

In the buffer chamber 237, as shown in FIG. 2, two rod-shaped

electrodes

269 and 270 made of a conductor and having an elongated structure are arranged along the stacking direction of the wafer 200 from the lower part to the upper part of the reaction tube 203. It is installed. Each of the rod-shaped

electrodes

269 and 270 is provided in parallel with the nozzle 249b. Each of the rod-shaped

electrodes

269 and 270 is protected by being covered with an electrode protection tube 275 from the upper part to the lower part. One of the rod-shaped

electrodes

269 and 270 is connected to the high-frequency power source 273 via the matching unit 272, and the other is connected to the ground that is the reference potential. By applying radio frequency (RF) power between the rod-shaped

electrodes

269 and 270 from the high-frequency power source 273 via the matching device 272, plasma is generated in the plasma generation region 224 between the rod-shaped

electrodes

269 and 270. The rod-shaped

electrodes

269 and 270 and the electrode protection tube 275 mainly constitute a plasma source as a plasma generator (plasma generator). The matching device 272 and the high-frequency power source 273 may be included in the plasma source. As will be described later, the plasma source functions as an excitation unit (activation mechanism) that excites (or activates) a gas into a plasma state, that is, a plasma state.

The electrode protection tube 275 has a structure in which each of the rod-shaped

electrodes

269 and 270 can be inserted into the buffer chamber 237 while being isolated from the atmosphere in the buffer chamber 237. If the O concentration inside the electrode protection tube 275 is about the same as the O concentration in the outside air (atmosphere), the rod-shaped

electrodes

269 and 270 inserted into the electrode protection tube 275 are oxidized by heat from the heater 207. . Or it is filled with an inert gas such as N ₂ gas into the electrode protection tube 275, by the interior of the electrode protection tube 275 is purged with an inert gas such as N ₂ gas using an inert gas purge mechanism, It is possible to reduce the O concentration inside the electrode protection tube 275 and prevent the rod-shaped

electrodes

269 and 270 from being oxidized.

The reaction tube 203 is provided with an exhaust pipe 231 for exhausting the atmosphere in the processing chamber 201. The exhaust pipe 231 is connected to a pressure sensor 245 as a pressure detector (pressure detection unit) for detecting the pressure in the processing chamber 201 and an APC (Auto Pressure Controller) valve 244 as a pressure regulator (pressure adjustment unit). A vacuum pump 246 as a vacuum exhaust device is connected. The APC valve 244 can perform vacuum evacuation and vacuum evacuation stop in the processing chamber 201 by opening and closing the valve with the vacuum pump 246 activated, and further, with the vacuum pump 246 activated, The valve is configured such that the pressure in the processing chamber 201 can be adjusted by adjusting the valve opening based on the pressure information detected by the pressure sensor 245. An exhaust system is mainly configured by the exhaust pipe 231, the APC valve 244, and the pressure sensor 245. The vacuum pump 246 may be included in the exhaust system.

Below the reaction tube 203, a seal cap 219 is provided as a furnace opening lid capable of airtightly closing the lower end opening of the reaction tube 203. The seal cap 219 is configured to contact the lower end of the reaction tube 203 from the lower side in the vertical direction. The seal cap 219 is made of a metal such as SUS and is formed in a disk shape. On the upper surface of the seal cap 219, an O-ring 220 is provided as a seal member that comes into contact with the lower end of the reaction tube 203. On the opposite side of the seal cap 219 from the processing chamber 201, a rotation mechanism 267 for rotating a boat 217 described later is installed. A rotation shaft 255 of the rotation mechanism 267 passes through the seal cap 219 and is connected to the boat 217. The rotation mechanism 267 is configured to rotate the wafer 200 by rotating the boat 217. The seal cap 219 is configured to be lifted and lowered in the vertical direction by a boat elevator 115 as a lifting mechanism vertically installed outside the reaction tube 203. The boat elevator 115 is configured so that the boat 217 can be carried in and out of the processing chamber 201 by moving the seal cap 219 up and down. That is, the boat elevator 115 is configured as a transfer device (transfer mechanism) that transfers the boat 217, that is, the wafers 200 into and out of the processing chamber 201.

The boat 217 as a substrate support is configured to support a plurality of, for example, 25 to 200, wafers 200 in a multi-stage manner by aligning them vertically in a horizontal posture and with their centers aligned. It is configured to arrange at intervals. The boat 217 is made of a heat-resistant material such as quartz or SiC. Under the boat 217, heat insulating plates 218 made of a heat-resistant material such as quartz or SiC are supported in multiple stages in a horizontal posture. With this configuration, heat from the heater 207 is not easily transmitted to the seal cap 219 side. However, this embodiment is not limited to the above-mentioned form. For example, instead of providing the heat insulating plate 218 in the lower portion of the boat 217, a heat insulating cylinder configured as a cylindrical member made of a heat resistant material such as quartz or SiC may be provided.

In the reaction tube 203, a temperature sensor 263 is installed as a temperature detector. By adjusting the power supply to the heater 207 based on the temperature information detected by the temperature sensor 263, the temperature in the processing chamber 201 becomes a desired temperature distribution. The temperature sensor 263 is configured in an L shape similarly to the

nozzles

249a and 249b, and is provided along the inner wall of the reaction tube 203.

As shown in FIG. 3, the controller 121, which is a control unit (control means), is configured as a computer having a CPU (Central Processing Unit) 121a, a RAM (Random Access Memory) 121b, a storage device 121c, and an I / O port 121d. Has been. The RAM 121b, the storage device 121c, and the I / O port 121d are configured to exchange data with the CPU 121a via the internal bus 121e. For example, an input / output device 122 configured as a touch panel or the like is connected to the controller 121.

The storage device 121c includes, for example, a flash memory, a HDD (Hard Disk Drive), and the like. In the storage device 121c, a control program that controls the operation of the substrate processing apparatus, a process recipe that describes the procedure and conditions of the substrate processing described later, and the like are stored in a readable manner. The process recipe is a combination of the controller 121 that allows the controller 121 to execute each procedure in the substrate processing process described later and obtain a predetermined result, and functions as a program. Hereinafter, the process recipe, the control program, and the like are collectively referred to simply as a program. When the term “program” is used in this specification, it may include only a process recipe alone, only a control program alone, or both. The RAM 121b is configured as a memory area (work area) in which programs, data, and the like read by the CPU 121a are temporarily stored.

The I / O port 121d includes the above-described MFCs 241a to 241d, valves 243a to 243d, pressure sensor 245, APC valve 244, vacuum pump 246, heater 207, temperature sensor 263, high frequency power supply 273, matching device 272, rotation mechanism 267, boat It is connected to the elevator 115 and the like.

The CPU 121a is configured to read and execute a control program from the storage device 121c, and to read a process recipe from the storage device 121c in response to an operation command input from the input / output device 122 or the like. The CPU 121a adjusts the flow rates of various gases by the MFCs 241a to 241d, the opening and closing operations of the valves 243a to 243d, the opening and closing operations of the APC valve 244, and the pressure by the APC valve 244 based on the pressure sensor 245 so as to match the contents of the read process recipe. Adjustment operation, start and stop of vacuum pump 246, temperature adjustment operation of heater 207 based on temperature sensor 263, power supply by high frequency power supply 273, impedance adjustment operation by matching unit 272, rotation and rotation speed adjustment of boat 217 by rotation mechanism 267 It is configured to control the operation, the raising / lowering operation of the boat 217 by the boat elevator 115 and the like.

The controller 121 is not limited to being configured as a dedicated computer, and may be configured as a general-purpose computer. For example, an external storage device storing the above-described program (for example, magnetic tape, magnetic disk such as a flexible disk or hard disk, optical disk such as CD or DVD, magneto-optical disk such as MO, semiconductor memory such as USB memory or memory card) 123 is prepared, and the controller 121 of this embodiment can be configured by installing a program in a general-purpose computer using the external storage device 123. However, the means for supplying the program to the computer is not limited to supplying the program via the external storage device 123. For example, the program may be supplied without using the external storage device 123 by using communication means such as the Internet or a dedicated line. The storage device 121c and the external storage device 123 are configured as computer-readable recording media. Hereinafter, these are collectively referred to simply as a recording medium. When the term “recording medium” is used in this specification, it may include only the storage device 121c alone, may include only the external storage device 123 alone, or may include both.

(2) Substrate Processing Step A sequence example in which a film is formed on a substrate as one step of a semiconductor device (device) manufacturing process using the above-described substrate processing apparatus will be described with reference to FIG. In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 121.

In the film forming sequence shown in FIG.
Supplying an HCDS gas as a source gas containing a predetermined element and a halogen element to a wafer 200 as a substrate;
Supplying a TMB gas as a first B-containing gas containing a borazine ring skeleton to the wafer 200;
Supplying a BCl ₃ gas as a second B-containing gas not containing a borazine ring skeleton to the wafer 200;
Is performed a predetermined number of times under the condition that the borazine ring skeleton in the TMB gas is maintained (maintained), so that a film having a borazine ring skeleton on the wafer 200 and containing Si, B, C, and N As a result, a silicon boron carbonitride film (SiBCN film) containing a borazine ring skeleton is formed.

In the above-described cycle, the step of supplying the HCDS gas, the step of supplying the TMB gas, and the step of supplying the BCl ₃ gas are performed non-simultaneously, that is, in this order without being synchronized. That is, the step of supplying the HCDS gas and the step of supplying the TMB gas are performed non-simultaneously in this order, and the step of supplying the TMB gas and the step of supplying BCl ₃ gas are performed non-simultaneously in this order.

In this specification, the above-described film forming sequence may be shown as follows for convenience.

(HCDS → TMB → BCl ₃ ) × n => SiBCN film

In this specification, when the term “wafer” is used, it means “wafer itself” or “a laminate (aggregate) of a wafer and a predetermined layer or film formed on the surface”. In other words, it may be called a wafer including a predetermined layer or film formed on the surface. In addition, when the term “wafer surface” is used in this specification, it means “the surface of the wafer itself (exposed surface)” or “the surface of a predetermined layer or film formed on the wafer”. That is, it may mean “the outermost surface of the wafer as a laminated body”.

Therefore, in the present specification, the phrase “supplying a predetermined gas to the wafer” means “supplying a predetermined gas directly to the surface (exposed surface) of the wafer itself”. , It may mean that “a predetermined gas is supplied to a layer, a film, or the like formed on the wafer, that is, to the outermost surface of the wafer as a laminated body”. Further, in this specification, when “describe a predetermined layer (or film) on the wafer” is described, “determine a predetermined layer (or film) directly on the surface (exposed surface) of the wafer itself”. This means that a predetermined layer (or film) is formed on a layer or film formed on the wafer, that is, on the outermost surface of the wafer as a laminate. There is a case.

In addition, when the term “substrate” is used in this specification, it is the same as the case where the term “wafer” is used. In that case, in the above description, “wafer” is replaced with “substrate”. Good.

(Wafer charge and boat load)
A plurality of wafers 200 are loaded into the boat 217 (wafer charge). Thereafter, as shown in FIG. 1, the boat 217 that supports the plurality of wafers 200 is lifted by the boat elevator 115 and loaded into the processing chamber 201 (boat loading). In this state, the seal cap 219 seals the lower end of the reaction tube 203 via the O-ring 220.

(Pressure adjustment and temperature adjustment)
Vacuum exhaust (reduced pressure) is performed by the vacuum pump 246 so that the processing chamber 201, that is, the space where the wafer 200 exists, has a desired pressure (degree of vacuum). At this time, the pressure in the processing chamber 201 is measured by the pressure sensor 245, and the APC valve 244 is feedback-controlled based on the measured pressure information. The vacuum pump 246 maintains a state in which it is always operated until at least the processing on the wafer 200 is completed. Further, the wafer 200 in the processing chamber 201 is heated by the heater 207 so as to reach a desired temperature. At this time, the power supply to the heater 207 is feedback-controlled based on the temperature information detected by the temperature sensor 263 so that the inside of the processing chamber 201 has a desired temperature distribution. Heating of the processing chamber 201 by the heater 207 is continuously performed at least until the processing on the wafer 200 is completed. Further, the rotation of the boat 217 and the wafers 200 by the rotation mechanism 267 is started. The rotation of the boat 217 and the wafer 200 by the rotation mechanism 267 is continuously performed at least until the processing on the wafer 200 is completed.

(SiBCN film formation process)
Thereafter, the next three steps, that is, steps 1 to 3 are sequentially executed.

[Step 1]
(HCDS gas supply)
In this step, HCDS gas is supplied to the wafer 200 in the processing chamber 201.

Here, the valve 243a is opened, and HCDS gas is caused to flow into the gas supply pipe 232a. The flow rate of the HCDS gas is adjusted by the MFC 241a, supplied into the processing chamber 201 through the nozzle 249a, and exhausted from the exhaust pipe 231. At this time, the HCDS gas is supplied to the wafer 200. At the same time, the valve 243c is opened and N ₂ gas is allowed to flow into the gas supply pipe 232c. The flow rate of the N ₂ gas is adjusted by the MFC 241c, supplied into the processing chamber 201 together with the HCDS gas, and exhausted from the exhaust pipe 231.

Further, in order to prevent the HCDS gas from entering the nozzle 249b, the valve 243d is opened, and N ₂ gas is allowed to flow into the gas supply pipe 232d. The N ₂ gas is supplied into the processing chamber 201 through the gas supply pipe 232b and the nozzle 249b, and is exhausted from the exhaust pipe 231.

The supply flow rate of the HCDS gas controlled by the MFC 241a is, for example, 1 to 2000 sccm, preferably 10 to 1000 sccm. The supply flow rate of N ₂ gas controlled by the MFCs 241c and 241d is set to a flow rate in the range of 100 to 10,000 sccm, for example. The pressure in the processing chamber 201 is, for example, 1 to 2666 Pa, preferably 67 to 1333 Pa. The time for supplying the HCDS gas to the wafer 200, that is, the gas supply time (irradiation time) is, for example, 1 to 120 seconds, preferably 1 to 60 seconds. The temperature of the heater 207 is set such that the temperature of the wafer 200 becomes, for example, a temperature in the range of 250 to 700 ° C., preferably 300 to 650 ° C., more preferably 350 to 600 ° C.

When the temperature of the wafer 200 is less than 250 ° C., it is difficult for HCDS to be chemically adsorbed on the wafer 200 and a practical film formation rate may not be obtained. This can be eliminated by setting the temperature of the wafer 200 to 250 ° C. or higher. By setting the temperature of the wafer 200 to 300 ° C. or higher, further 350 ° C. or higher, HCDS can be more sufficiently adsorbed on the wafer 200 and a more sufficient film formation rate can be obtained.

When the temperature of the wafer 200 exceeds 700 ° C., the CVD reaction becomes too strong (excess gas phase reaction occurs), so that the film thickness uniformity tends to be deteriorated and the control becomes difficult. When the temperature of the wafer 200 is set to 700 ° C. or lower, an appropriate gas phase reaction can be caused, so that deterioration in film thickness uniformity can be suppressed and control thereof is possible. In particular, when the temperature of the wafer 200 is set to 650 ° C. or lower, and further to 600 ° C. or lower, the surface reaction becomes dominant over the gas phase reaction, the film thickness uniformity is easily ensured, and the control thereof is facilitated.

Therefore, the temperature of the wafer 200 is set to 250 to 700 ° C., preferably 300 to 650 ° C., more preferably 350 to 600 ° C.

By supplying HCDS gas to the wafer 200 under the above-described conditions, the first layer includes Si containing, for example, Cl having a thickness of less than one atomic layer to several atomic layers on the outermost surface of the wafer 200. A layer is formed. The Si-containing layer containing Cl may be a Si layer containing Cl, an adsorption layer of HCDS, or both of them.

The Si layer containing Cl is a generic name including a continuous layer made of Si and containing Cl, as well as a discontinuous layer and a Si thin film containing Cl formed by overlapping these layers. A continuous layer made of Si and containing Cl may be referred to as a Si thin film containing Cl. Si constituting the Si layer containing Cl includes not only those that are not completely disconnected from Cl but also those that are completely disconnected from Cl.

The adsorption layer of HCDS includes a discontinuous adsorption layer as well as a continuous adsorption layer composed of HCDS molecules. That is, the adsorption layer of HCDS includes an adsorption layer having a thickness of less than one molecular layer composed of HCDS molecules or less than one molecular layer. The HCDS molecules constituting the HCDS adsorption layer include those in which the bond between Si and Cl is partially broken. That is, the HCDS adsorption layer may be an HCDS physical adsorption layer, an HCDS chemical adsorption layer, or both of them.

Here, a layer having a thickness of less than one atomic layer means an atomic layer formed discontinuously, and a layer having a thickness of one atomic layer means an atomic layer formed continuously. Means. A layer having a thickness of less than one molecular layer means a molecular layer formed discontinuously, and a layer having a thickness of one molecular layer means a molecular layer formed continuously. ing. The Si-containing layer containing Cl can include both a Si layer containing Cl and an adsorption layer of HCDS. However, as described above, the Si-containing layer containing Cl is expressed using expressions such as “one atomic layer” and “several atomic layer”.

Under conditions where the HCDS gas undergoes self-decomposition (thermal decomposition), that is, under conditions where a thermal decomposition reaction of the HCDS gas occurs, Si is deposited on the wafer 200 to form a Si layer containing Cl. Under the condition that the HCDS gas does not self-decompose (thermally decompose), that is, under the condition that the thermal decomposition reaction of the HCDS gas does not occur, the adsorption layer of HCDS is formed by adsorbing HCDS on the wafer 200. It is more preferable to form a Si layer containing Cl on the wafer 200 than to form an HCDS adsorption layer on the wafer 200 in that the film formation rate can be increased.

When the thickness of the first layer exceeds several atomic layers, the modification effect in Steps 2 and 3 described later does not reach the entire first layer. Moreover, the minimum value of the thickness of the first layer is less than one atomic layer. Therefore, the thickness of the first layer is preferably less than one atomic layer to several atomic layers. By setting the thickness of the first layer to 1 atomic layer or less, that is, 1 atomic layer or less than 1 atomic layer, the action of the reforming reaction in Steps 2 and 3 described later can be relatively increased, The time required for the reforming reaction in steps 2 and 3 can be shortened. The time required for forming the first layer in Step 1 can also be shortened. As a result, the processing time per cycle can be shortened, and the total processing time can be shortened. That is, the film forming rate can be increased. Further, by controlling the thickness of the first layer to 1 atomic layer or less, it becomes possible to improve the controllability of film thickness uniformity.

In addition, it is preferable that the HCDS gas is supplied by being thermally activated by non-plasma because the above-described reaction can be progressed softly and the first layer can be easily formed. That is, when the HCDS gas is supplied after being thermally activated by non-plasma, it is possible to prevent an excessive gas phase reaction in the processing chamber 201 than when the HCDS gas is supplied after being excited by plasma. It is preferable in that the generation of particles in can be suppressed. Further, it is preferable in that the step coverage and film thickness controllability of the first layer, that is, the finally formed SiBCN film can be improved.

(Residual gas removal)
After the first layer is formed, the valve 243a is closed and the supply of HCDS gas is stopped. At this time, the APC valve 244 is kept open, the processing chamber 201 is evacuated by the vacuum pump 246, and the HCDS gas remaining in the processing chamber 201 or contributing to the formation of the first layer is processed. Exclude from the chamber 201. At this time, the

valves

243c and 243d remain open, and the supply of N ₂ gas into the processing chamber 201 is maintained. The N ₂ gas acts as a purge gas, which can enhance the effect of removing the gas remaining in the processing chamber 201 from the processing chamber 201.

At this time, the gas remaining in the processing chamber 201 may not be completely removed, and the inside of the processing chamber 201 may not be completely purged. If the amount of gas remaining in the processing chamber 201 is very small, there will be no adverse effect in the subsequent step 2. The flow rate of the N ₂ gas supplied into the processing chamber 201 does not need to be a large flow rate. For example, by supplying an amount of N ₂ gas equivalent to the volume of the reaction tube 203 (processing chamber 201), step 2 is performed. Purging can be performed to such an extent that no adverse effect is caused. Thus, by not completely purging the inside of the processing chamber 201, the purge time can be shortened and the throughput can be improved. The consumption of N ₂ gas can be suppressed to the minimum necessary.

As source gases, in addition to HCDS gas, for example, OCTS gas, dichlorosilane (SiH ₂ Cl ₂ , abbreviation: DCS) gas, monochlorosilane (SiH ₃ Cl, abbreviation: MCS) gas, tetrachlorosilane, that is, silicon tetrachloride (SiCl) ₄ , an abbreviated name: STC) gas, an inorganic halosilane source gas such as trichlorosilane (SiHCl ₃ , abbreviated name: TCS) gas can be used, and as the source gas, BTCSE gas, BTCSM gas, TCDMDS gas, DCTMDS An organic halosilane source gas such as gas or MCPMDS gas can be used. When an organic halosilane source gas that also acts as a C source is used as the source gas, a Si-containing layer containing C and Cl is formed as the first layer, and as a result, the SiBCN finally formed The C concentration in the film can be increased as compared with the case where an inorganic halosilane source gas is used as the source gas.

As the inert gas, for example, a rare gas such as Ar gas, He gas, Ne gas, or Xe gas can be used in addition to N ₂ gas.

[Step 2]
(TMB gas supply)
After step 1 is completed, TMB gas is supplied to the wafer 200 in the processing chamber 201.

In this step, the opening / closing control of the valves 243b to 243d is performed in the same procedure as the opening / closing control of the

valves

243a, 243c, 243d in Step 1. The supply flow rate of the TMB gas controlled by the MFC 241b is set, for example, within a range of 1 to 1000 sccm. The pressure in the processing chamber 201 is, for example, 1 to 2666 Pa, preferably 67 to 1333 Pa. The partial pressure of the TMB gas in the processing chamber 201 is, for example, a pressure in the range of 0.0001 to 2424 Pa. The time for supplying the TMB gas to the wafer 200, that is, the gas supply time (irradiation time) is, for example, 1 to 120 seconds, preferably 1 to 60 seconds. Other processing procedures and processing conditions are the same as, for example, the processing procedures and processing conditions in step 1.

By supplying TMB gas to the wafer 200 under the above-described conditions, the first layer formed in Step 1 reacts with TMB gas. That is, Cl (chloro group) contained in the first layer reacts with a ligand (methyl group, hereinafter also referred to as “organic ligand” or “methyl ligand”) contained in TMB. Thereby, Cl of the first layer reacted with methyl ligand of TMB is separated (pulled out) from the first layer, and methyl ligand of TMB reacted with Cl of the first layer is separated from TMB. Can be made. And N which comprises the borazine ring of TMB which the methyl ligand isolate | separated, and Si of a 1st layer can be combined. That is, among the B and N constituting the borazine ring of TMB, the methyl ligand is removed and N has a dangling bond, and it is included in the first layer and has a dangling bond. Si-N bonds can be formed by bonding Si or Si having dangling bonds. At this time, the borazine ring skeleton constituting the borazine ring of TMB is retained without being broken. In addition, the bond between the borazine ring and the methyl ligand, that is, the N—C bond of TMB is also retained without being broken. Note that the methyl group is one of alkyl groups, and the methyl ligand can also be referred to as an alkyl ligand.

By supplying TMB gas under the above-described conditions, the first layer and TMB can be appropriately reacted while maintaining the borazine ring skeleton and part of the N—C bond in TMB without breaking them. And the above-described series of reactions can be caused. The most important factors (conditions) for causing this series of reactions in a state where the borazine ring skeleton of TMB is held are considered to be the temperature of the wafer 200 and the pressure in the processing chamber 201, particularly the temperature of the wafer 200. By properly controlling these, it becomes possible to cause an appropriate reaction.

</ RTI> By this series of reactions, a borazine ring is newly incorporated into the first layer. In addition, some methyl ligands of TMB, that is, some N—C bonds of TMB are newly incorporated into the first layer. Thereby, the first layer changes to a second layer having a borazine ring skeleton and containing Si, B, C and N, that is, a silicon borocarbonitride layer (SiBCN layer) containing a borazine ring skeleton ( Modified). For example, the second layer is a layer having a thickness of less than one atomic layer to several atomic layers. It can be said that the SiBCN layer containing a borazine ring skeleton is a layer containing Si, C, and a borazine ring skeleton.

When the borazine ring is newly taken into the first layer, the B component and N component constituting the borazine ring are newly taken into the first layer. At this time, the C component contained in the TMB ligand is also taken into the first layer. In this way, by reacting the first layer with TMB and incorporating the C component contained in the borazine ring or methyl ligand into the first layer, the B component, C component and N component can be newly added.

When forming the second layer, Cl contained in the first layer constitutes a gaseous substance containing at least Cl in the process of the reforming reaction of the first layer with TMB gas. It is discharged from the inside. That is, impurities such as Cl in the first layer are separated from the first layer by being extracted or desorbed from the first layer. Accordingly, the second layer is a layer having less impurities such as Cl than the first layer.

When forming the second layer, by maintaining (holding) the borazine ring skeleton constituting the borazine ring contained in TMB without destroying it, the center space of the borazine ring can be maintained (held), It becomes possible to form a porous SiBCN layer.

In addition, it is preferable that the TMB gas is supplied by being thermally activated by non-plasma because the above-described reaction can be performed softly and the second layer can be easily formed. In other words, the TMB gas is maintained without being destroyed by destroying the borazine ring skeleton and some of the N—C bonds in the TMB when supplied by being thermally activated with non-plasma rather than being supplied with plasma excitation. However, it is preferable in that it can be easily incorporated into the second layer.

(Residual gas removal)
After the second layer is formed, the valve 243b is closed and the supply of TMB gas is stopped. Then, TMB gas and reaction byproducts remaining in the processing chamber 201 or contributed to the formation of the second layer are removed from the processing chamber 201 by the same processing procedure as that in Step 1. At this time, it is the same as in step 1 that the gas remaining in the processing chamber 201 does not have to be completely removed.

As a gas containing a borazine ring skeleton, for example, TEB gas, TPB gas, TIPB gas, TBB gas, TIBB gas and the like can be used in addition to TMB gas. As the inert gas, for example, a rare gas such as Ar gas, He gas, Ne gas, or Xe gas can be used in addition to N ₂ gas.

[Step 3]
(BCl ₃ gas supply)
After step 1 is completed, BCl ₃ gas is supplied to the wafer 200 in the processing chamber 201.

valves

243a, 243c, 243d in Step 1. The supply flow rate of the BCl ₃ gas controlled by the MFC 241b is set to a flow rate in the range of 100 to 10,000 sccm, for example. The pressure in the processing chamber 201 is, for example, 1 to 2666 Pa, preferably 67 to 1333 Pa. The partial pressure of the BCl ₃ gas in the processing chamber 201 is, for example, a pressure in the range of 0.01 to 2640 Pa. The time for supplying the BCl ₃ gas to the wafer 200, that is, the gas supply time (irradiation time) is, for example, 1 to 120 seconds, preferably 1 to 60 seconds. Other processing procedures and processing conditions are the same as, for example, the processing procedures and processing conditions in step 1.

By supplying BCl ₃ gas to the wafer 200 under the above-described conditions, the second layer formed in Step 2 reacts with BCl ₃ gas. That is, a ligand (methyl group) bonded to N constituting the borazine ring skeleton contained in the second layer reacts with Cl (chloro group) contained in BCl ₃ . Thereby, the methyl ligand of the second layer reacted with Cl of BCl ₃ is separated (pulled out) from the second layer, and the Cl of BCl ₃ reacted with the methyl ligand of the second layer is converted to BCl _3. ₃ can be separated. Then, B of BCl ₃ from which Cl has been separated and N constituting the borazine ring contained in the second layer from which the methyl ligand has been separated can be bonded. That is, among B of BCl ₃ that has had a dangling bond due to Cl being released, and B and N that constitute the borazine ring skeleton included in the second layer, the methyl ligand has come off and has a dangling bond. It becomes possible to form a BN bond by combining N which has become to be N or N having an unbonded hand. In addition, B in BCl ₃ that has had a dangling bond due to the release of Cl, and Si, B, or C contained in the second layer had a dangling bond or was not bonded It becomes possible to form Si—B bonds, BB bonds, and BC bonds by bonding Si, B, and C that have had hands. At this time, the borazine ring skeleton constituting the borazine ring contained in the second layer is held without breaking. In addition, a part of the methyl ligand contained in the second layer is also retained in the layer without desorbing from the second layer. That is, some of the N—C bonds contained in the second layer are retained without being broken.

By supplying the BCl ₃ gas under the above-described conditions, the borazine ring skeleton and some N—C bonds contained in the second layer are maintained without being broken, and the second layer and the BCl ₃ Can be appropriately reacted, and the above-described series of reactions can be caused. The most important factors (conditions) for causing this series of reactions while holding the borazine ring skeleton and the like contained in the second layer are the temperature of the wafer 200 and the pressure in the processing chamber 201, particularly the wafer 200. It is possible to cause an appropriate reaction by appropriately controlling these temperatures.

By this series of reactions, B is further incorporated into the second layer, and the second layer is a B-rich third layer having a borazine ring skeleton and containing Si, B, C, and N, that is, borazine. It is changed (modified) into a B-rich SiBCN layer containing a ring skeleton. The third layer is, for example, a layer having a thickness of less than one atomic layer to several atomic layers. A B-rich SiBCN layer containing a borazine ring skeleton can be said to be a layer containing Si, B, C, and a borazine ring skeleton.

By incorporating the B component contained in BCl ₃ into the third layer, the third layer has a higher B concentration in the layer than the second layer, that is, a B-rich layer and Become. Further, when forming the third layer, a part of the methyl ligand contained in the second layer is separated from the second layer, and the rest is held in the second layer. . Thereby, the third layer is a layer having a lower C concentration in the layer than the second layer, that is, a carbon poor layer. When forming the third layer, it is possible to form a porous SiBCN layer by maintaining (holding) the borazine ring skeleton constituting the borazine ring contained in the second layer without destroying it. Is the same as step 2.

Note that the BCl ₃ gas is preferably supplied by being thermally activated by non-plasma from the viewpoint that the above-described reaction can be performed softly and the formation of the third layer is facilitated. That, BCl ₃ gas, who was fed thermally activated in a non-plasma, rather than supplied by plasma excitation, it is possible to prevent the BCl ₃ gas is excessively activated, the The borazine ring skeleton and a part of N—C bonds in the second layer are preferably maintained without being destroyed.

(Residual gas removal)
After the third layer is formed, the valve 243b is closed and the supply of BCl ₃ gas is stopped. Then, BCl ₃ gas and reaction by-products remaining in the processing chamber 201 and contributed to the formation of the third layer are removed from the processing chamber 201 by the same processing procedure as in step 1. At this time, it is the same as in step 1 that the gas remaining in the processing chamber 201 does not have to be completely removed.

The borazine ring skeleton-free B-containing gas, BCl ₃ gas other than halogenated boron-based gas (Haroboran based gas), for example, BCl ₃ and chloroborane based gas other than the gas, trifluoroborane (BF ₃₎ such as a gas A bromoborane-based gas such as a fluoroborane-based gas or a tribromoborane (BBr ₃ ) gas can be used. Further, a Cl-free borane-based gas such as B ₂ H ₆ gas can also be used. In addition to these inorganic borane-based gases, organic borane-based gases can also be used. As the inert gas, for example, a rare gas such as Ar gas, He gas, Ne gas, or Xe gas can be used in addition to N ₂ gas.

(Performed times)
A SiBCN film including a borazine ring skeleton having a predetermined composition and a predetermined film thickness can be formed on the wafer 200 by performing the above-described steps 1 to 3 non-simultaneously at least once (a predetermined number of times). The above cycle is preferably repeated multiple times. That is, it is preferable that the thickness of the SiBCN layer formed per cycle is made smaller than the desired film thickness, and the above-described cycle is repeated a plurality of times until the desired film thickness is obtained.

(Purge and return to atmospheric pressure)
The

valves

243c and 243d are opened, N ₂ gas is supplied into the processing chamber 201 from the

gas supply pipes

232c and 232d, and exhausted from the exhaust pipe 231. N ₂ gas acts as a purge gas. Thereby, the inside of the processing chamber 201 is purged, and the gas and reaction by-products remaining in the processing chamber 201 are removed from the processing chamber 201 (purge). Thereafter, the atmosphere in the processing chamber 201 is replaced with an inert gas (inert gas replacement), and the pressure in the processing chamber 201 is returned to normal pressure (return to atmospheric pressure).

(Boat unload and wafer discharge)
The seal cap 219 is lowered by the boat elevator 115 and the lower end of the reaction tube 203 is opened. Then, the processed wafer 200 is carried out from the lower end of the reaction tube 203 to the outside of the reaction tube 203 (boat unloading) while being supported by the boat 217. The processed wafer 200 is taken out from the boat 217 (wafer discharge).

(3) Effects According to the Present Embodiment According to the present embodiment, one or more effects shown below can be obtained.

(A) By performing a predetermined number of cycles including step 1 for supplying HCDS gas, step 2 for supplying TMB gas, and step 3 for supplying BCl ₃ gas, the SiBCN film finally formed The controllability of the composition ratio can be improved. That is, the composition of the SiBCN film finally formed by performing the film forming process using not only the TMB gas containing B and N but also the BCl ₃ gas containing B and not containing N as the B-containing gas. The ratio can be precisely controlled.

This is because, in the SiBCN film formed using HCDS gas and TMB gas without using BCl ₃ gas, the ratio of B component and N component contained in the film (hereinafter also referred to as B / N ratio) The ratio is determined by the ratio of the number of B and the number of N contained in one molecule of the TMB gas (1/1 in the case of TMB gas), that is, the type of gas containing the borazine ring skeleton. That is, it is difficult to set the B / N ratio described above to a value far from 1/1 in a SiBCN film formed using HCDS gas and TMB gas without using BCl ₃ gas.

On the other hand, as in the present embodiment, as the B-containing gas, two types of gases (double B source) including TMB gas containing B and N and BCl ₃ gas containing B and not containing N are used. When the film forming process is performed, the B / N ratio of the SiBCN film to be finally formed can be freely controlled by appropriately adjusting the supply conditions of these gases.

For example, by increasing the ratio of “the supply flow rate of BCl ₃ gas in step 3” to “the supply flow rate of TMB gas in step 2” (hereinafter also referred to as “BCl ₃ gas supply flow rate / TMB gas supply flow rate”), In step 3, the amount of the B component added to the third layer is increased, and the B / N ratio of the finally formed SiBCN film can be increased (larger than 1/1). Further, by reducing the above-mentioned “BCl ₃ gas supply flow rate / TMB gas supply flow rate”, the amount of B component added to the third layer in Step 3 is appropriately suppressed, and finally formed SiBCN. It is possible to reduce the B / N ratio of the film (close to 1/1).

In addition, for example, the ratio of "BCl ₃ gas supply time in Step 3" to "supply time of the TMB gas in Step 2" (hereinafter also referred to as "BCl ₃ gas supply time / TMB gas supply time") to increase the In Step 3, it is possible to increase the amount of the B component added to the third layer and increase the B / N ratio of the SiBCN film to be finally formed (greater than 1/1). Further, by reducing the above-mentioned “BCl ₃ gas supply time / TMB gas supply time”, the amount of B component added to the third layer in Step 3 is appropriately suppressed, and finally formed SiBCN. It is possible to reduce the B / N ratio of the film (close to 1/1).

Further, for example, a ratio of “pressure in the processing chamber 201 in step 3” to “pressure in the processing chamber 201 in step 2” (hereinafter also referred to as “processing pressure in step 3 / processing pressure in step 2”). By increasing the size, the amount of the B component added to the third layer in Step 3 is increased, and the B / N ratio of the SiBCN film finally formed is increased (made larger than 1/1). It becomes possible. Further, by reducing the above-mentioned “processing pressure in step 3 / processing pressure in step 2”, the amount of the B component added to the third layer in step 3 is appropriately suppressed and finally formed. It is possible to reduce the B / N ratio of the SiBCN film to be close (close to 1/1).

Further, for example, a ratio of “partial pressure of BCl ₃ gas in the processing chamber 201 in step 3” to “partial pressure of TMB gas in the processing chamber 201 in step 2” (hereinafter referred to as “BCl ₃ gas partial pressure / TMB”). By increasing the gas partial pressure ”, the amount of B component added to the third layer in step 3 is increased, and the B / N ratio of the SiBCN film finally formed is increased (1 / Greater than 1). Further, by reducing the above-mentioned “BCl ₃ gas partial pressure / TMB gas partial pressure”, the amount of B component added to the third layer in Step 3 is appropriately suppressed, and finally formed SiBCN. It is possible to reduce the B / N ratio of the film (close to 1/1).

Further, as in the present embodiment, the film is formed by using two types of gas, that is, a TMB gas containing C and a BCl ₃ gas containing no C as the B-containing gas. It becomes possible to finely adjust the C concentration in the SiBCN film. That is, in addition to Steps 1 and 2, Step 3 for supplying C-free BCl ₃ gas is further performed, so that Steps 1 and 2 are alternately performed with respect to the C concentration in the finally formed SiBCN film. It is possible to control the concentration so as to be an arbitrary concentration lower than the C concentration in the SiBCN film formed in (1).

(B) As a B-containing gas, a film is formed using two types of gases, a TMB gas containing a borazine ring skeleton and a BCl ₃ gas not containing a borazine ring skeleton, and finally formed. It becomes possible to improve the oxidation resistance of the SiBCN film.

This is because the SiBCN film containing a borazine ring skeleton contains B as one component of the borazine ring skeleton constituting the film. The BN bond constituting the borazine ring skeleton has a small bond (small polarity) and has a strong bond. Therefore, a SiBCN film containing a borazine ring skeleton has a lower probability of desorption of B from the film due to oxidation than a SiBCN film not containing a borazine ring skeleton, and a film having high resistance to oxidation resistance, for example, oxygen plasma, That is, the film has high ashing resistance.

As in the present embodiment, the final film formation process is performed by using two types of gases, a TMB gas containing a borazine ring skeleton and a BCl ₃ gas not containing a borazine ring skeleton, as the B-containing gas. The oxidation resistance of the SiBCN film formed on the silicon nitride film can be made higher than that of the SiBCN film not containing a borazine ring skeleton. That is, Step 2 for supplying a TMB gas containing a borazine ring skeleton is performed between Steps 1 and 3 and the borazine ring skeleton is included in the finally formed SiBCN film, for example, HCDS gas, BCl ₃ Compared to a SiBCN film not containing a borazine ring skeleton formed by using gas, C ₃ H ₆ gas, NH ₃ gas, or the like, it is possible to reduce the probability of B desorption from the film due to oxidation. That is, the oxidation resistance of the film, that is, the ashing resistance can be improved.

In addition to the B constituting the borazine ring skeleton, the inventors have added B in the third layer by performing Step 3, that is, the borazine ring skeleton contained in the film. It has also been confirmed that the probability of desorption from the film can be reduced even for B which is not a constituent element. This is because the borazine ring skeleton contained in the SiBCN film is added to the third layer by performing step 3 on the oxygen plasma or the like supplied to the film, for example, One reason is considered to act as a protective (guard) element that suppresses the elimination of B, which is bound to N or the like constituting the borazine ring. When the inventors supply oxygen plasma or the like to the borazine ring skeleton-free SiBCN film, desorption from the film tends to occur in the order of B, C, N, that is, B, C, It has been confirmed that among N, B is most easily desorbed and then C is easily desorbed.

(C) As a B-containing gas, a film is formed using two types of gases, a TMB gas containing a borazine ring skeleton and a BCl ₃ gas not containing a borazine ring skeleton, and finally formed. It is possible to appropriately reduce the film density of the SiBCN film, that is, the atomic density of the film. As a result, it is possible to appropriately increase the dielectric constant of the finally formed SiBCN film.

This is because a film containing a borazine ring skeleton (porous film) has a lower atomic density and a lower dielectric constant than a film not containing a borazine ring skeleton (non-porous film). . Therefore, as the B-containing gas, film formation is performed using two kinds of gases, ie, a TMB gas containing a borazine ring skeleton and a BCl ₃ gas not containing a borazine ring skeleton, and in the SiBCN film finally formed By including a borazine ring skeleton in the film, it is possible to appropriately reduce the film density of the film and increase the dielectric constant. Furthermore, the processing conditions in Steps 2 and 3 are controlled as described above, and the amount of borazine ring skeleton contained in this film is adjusted, so that the dielectric constant of this film can be changed to, for example, HCDS gas or BCl ₃ gas. The dielectric constant of a borazine ring skeleton-free SiBCN film formed using C ₃ H ₆ gas, NH ₃ gas, etc., and the dielectric constant of a SiBCN film including a borazine ring skeleton formed using HCDS gas and TMB gas It is possible to control to be an arbitrary value between.

That is, according to the present embodiment, the dielectric constant of the finally formed SiBCN film can be made higher than that of the borazine ring skeleton-free SiBCN film. Furthermore, the dielectric constant of the SiBCN film to be finally formed is set such that when a SiBCN film containing no borazine ring skeleton is formed, or when a SiBCN film containing a borazine ring skeleton is formed using HCDS gas or TMB gas, etc. The value can not be realized. That is, it is possible to widen the window for controlling the dielectric constant. Further, by controlling the TMB gas and BCl ₃ gas supply conditions in steps 2 and _{3 as} described above, for example, the dielectric constant of the finally formed SiBCN film can be finely adjusted.

(D) As a B-containing gas, a film is formed using two types of gases, a TMB gas containing a borazine ring skeleton and a BCl ₃ gas not containing a borazine ring skeleton, and finally formed. It becomes possible to improve the surface roughness of the SiBCN film.

Here, “surface roughness” means a height difference in the wafer surface or in an arbitrary target surface, and has the same meaning as the surface roughness. The improvement in surface roughness (good) means that this height difference becomes small (small), that is, the surface becomes smooth (smooth). Deteriorating (poor) surface roughness means that this height difference becomes large (large), that is, the surface becomes rough (coarse).

A film containing no borazine ring skeleton tends to have better surface roughness than a film containing a borazine ring skeleton. Therefore, it is possible to improve the surface roughness of the finally formed SiBCN film by further performing Step 3 of supplying a C-free B-containing gas in addition to Steps 1 and 2. That is, as a B-containing gas, a film forming process is performed using two kinds of gases, a TMB gas containing a borazine ring skeleton and a BCl ₃ gas not containing a borazine ring skeleton, and the SiBCN film finally formed By appropriately adjusting the amount of the borazine ring skeleton contained in the film, the surface roughness of this film can be made higher than that of the SiBCN film containing a borazine ring skeleton formed using HCDS gas and TMB gas without using BCl ₃ gas. It becomes possible to improve.

(E) By using the TMB gas obtained by vaporizing the organic borazine compound in Step 2, an appropriate amount of C can be contained in the finally formed film. That is, in step 2, a step of supplying a C-containing gas such as C ₃ H ₆ gas by using a B-containing gas that contains an organic ligand in one molecule such as TMB gas and also acts as a C source is newly added. It is possible to form a SiBN film containing C, that is, a SiBCN film on the wafer 200 without adding to the above. Thus, by including an appropriate amount of C in the film, it is possible to increase the resistance of this film to hydrogen fluoride (HF), that is, the etching resistance.

(F) In Step 1, a halosilane source gas (silane source gas containing a halogen element) is used, in Step 2, an organic borazine gas (borazine compound gas containing an organic ligand) is used, and in Step 3, a haloborane gas (borane containing a halogen element) is used. By using a compound gas) and performing a cycle of performing steps 1 to 3 non-simultaneously in this order a predetermined number of times, it is possible to efficiently perform the formation process of the first to third layers, that is, the formation of the SiBCN film. It becomes.

This is because the HCDS gas containing Cl, that is, the halosilane source gas having a high adsorptivity to the base, is supplied to the wafer 200 in Step 1, thereby efficiently forming the first layer on the wafer 200. It is possible to make progress.

In addition, after forming the Si-containing layer containing Cl as the first layer in Step 1, the second layer is formed by supplying TMB gas containing an organic ligand to the first layer in Step 2. It becomes possible to carry out efficiently. That is, in step 2, the reaction efficiency between the first layer and the TMB gas can be increased by utilizing the reaction between Cl contained in the first layer and the organic ligand contained in the TMB gas. Become. As a result, the formation process of the second layer can be efficiently advanced.

Further, after forming a SiBCN layer containing an organic ligand as the second layer in Step 2, a third layer is formed by supplying BCl ₃ gas containing Cl to the second layer in Step 3. It becomes possible to carry out efficiently. That is, in step 3, and the organic ligands included in the second layer, by using a Cl contained in the BCl ₃ gas, a reaction, to increase the reaction efficiency between the second layer and the BCl ₃ gas It becomes possible. As a result, it is possible to efficiently proceed with the formation process of the third layer.

Thus, when performing the above-described cycle, after supplying a gas containing a halogen element, a gas containing an organic ligand is supplied, and after supplying a gas containing an organic ligand, a gas containing a halogen element is supplied. The layer formed on the wafer 200 and the gas supplied to this layer can be reacted efficiently. As a result, the formation rate of the first to third layers can be increased, and the film formation rate of the SiBCN film to be finally formed can be improved. In addition, it is possible to reduce the amount of gas (raw material gas, reaction gas) that is exhausted from the processing chamber 201 without contributing to the film formation process, thereby reducing the film formation cost.

(G) By performing steps 1 to 3 non-simultaneously, that is, by performing non-simultaneous operations without synchronizing the supply of the source gas and the reaction gas (first B-containing gas, second B-containing gas), This gas can be properly contributed to the reaction under conditions where a gas phase reaction and a surface reaction occur appropriately. As a result, the step coverage and film thickness controllability of the finally formed SiBCN film can be improved. In addition, excessive gas phase reaction in the processing chamber 201 can be avoided, and generation of particles can be suppressed.

(H) The above-described effects are obtained when a source gas other than the HCDS gas is used as the source gas, when a B-containing gas containing a borazine ring skeleton other than the TMB gas is used as the first B-containing gas, or when the second B The same can be obtained when a B-containing gas not containing a borazine ring skeleton other than BCl ₃ gas is used as the containing gas.

(4) Modified Example The film forming sequence in the present embodiment is not limited to the mode shown in FIG. 4 and can be changed as in the following modified example.

(Modifications 1 to 3)
For example, a film containing a borazine ring skeleton may be formed on the wafer 200 by the following film formation sequence (in order of Modifications 1 to 3). Also by this modification, the same effect as the film-forming sequence shown in FIG. 4 can be acquired.

(HCDS → BCl ₃ → TMB) × n ⇒ SiBCN film

(BCl ₃ → HCDS → TMB) × n ⇒ SiBCN film

(BCl ₃ → TMB → HCDS) × n ⇒ SiBCN film

(Modifications 4 to 7)
Further, for example, a step of supplying NH ₃ gas to the wafer 200 may be further performed during the above-described cycle, as in the following film forming sequence (in order of Modifications 4 to 7). FIG. 5 is a diagram illustrating the gas supply timing in the fourth modification.

(HCDS → TMB → BCl ₃ → NH ₃ ) × n ⇒ SiBCN film or SiBN film

(HCDS → BCl ₃ → TMB → NH ₃ ) × n => SiBCN film or SiBN film

(BCl ₃ → HCDS → TMB → NH ₃ ) × n => SiBCN film or SiBN film

(BCl ₃ → TMB → HCDS → NH ₃ ) × n ⇒ SiBCN film or SiBN film

Also by these modified examples, the same effect as the film forming sequence shown in FIG. 4 can be obtained. Further, by performing the step of supplying NH ₃ gas, the N component contained in the NH ₃ gas can be added to the layers formed so far (SiBCN layer), the layer, N concentration Can be modified (nitrided) into a high layer (N-rich SiBCN layer). As a result, it is possible to increase the N concentration in the finally formed SiBCN film. Further, most of C contained in the SiBCN layer can be eliminated to an impurity level, or C contained in the SiBCN layer can be substantially eliminated. It can also be modified to a layer (SiBN layer). In this case, a C-free silicon boronitride film (SiBN film) containing a borazine ring skeleton can also be formed on the wafer 200.

Note that the step of supplying NH ₃ gas can be performed simultaneously with the steps of supplying other gases. Further, the NH ₃ gas can be supplied by being activated by heat, or can be supplied after being excited by plasma.

(Modifications 8 and 9)
Further, for example, as in the following film forming sequence (in order of Modifications 8 and 9), when performing the above-described cycle, the step of supplying TMB gas and the step of supplying BCl ₃ gas are performed simultaneously. It may be. FIG. 6 is a diagram illustrating the gas supply timing in the modification 8. FIG. 7 is a diagram illustrating the gas supply timing in the modification 9. Also by these modified examples, the same effect as the film forming sequence shown in FIG. 4 can be obtained.

(HCDS → [TMB + BCl ₃ ]) × n => SiBCN film

(HCDS → [TMB + BCl ₃ ] → NH ₃ ) × n => SiBCN film or SiBN film

(Modification 10)
The film forming sequence shown in FIG. 4 and each of the above-described modifications may further include a step of supplying a C-containing gas such as a C ₃ H ₆ gas to the wafer 200. The step of supplying the C ₃ H ₆ gas can be performed non-simultaneously with the step of supplying the HCDS gas, the step of supplying the TMB gas, the step of supplying the BCl ₃ gas, or at least one of these steps. It can be performed simultaneously with the steps. For example, the step of supplying the C ₃ H ₆ gas may be performed simultaneously with the step of supplying the TMB gas.

Also according to this modification, the same effects as those of the film forming sequence shown in FIG. 4 and each of the modifications described above can be obtained. Moreover, according to this modification, it becomes possible to add the C component contained in the C ₃ H ₆ gas to the finally formed film, and the C concentration in the finally formed film Can be further increased. However, excessive gas phase reaction in the processing chamber 201 can be avoided by supplying the C ₃ H ₆ gas at the same time as the reaction gas rather than at the same time as the source gas. It is preferable in that generation of particles can be suppressed.

(Processing conditions)
In the above-described modification, in the step of supplying the NH ₃ gas to the wafer 200 after being activated by heat, the supply flow rate of the NH ₃ gas controlled by the MFC 241b is set to a flow rate in the range of, for example, 100 to 10,000 sccm. The pressure in the processing chamber 201 is, for example, 1 to 4000 Pa, preferably 1 to 3000 Pa. In addition, the partial pressure of the NH ₃ gas in the processing chamber 201 is set to a pressure in the range of 0.01 to 3960 Pa, for example. The time for supplying the NH ₃ gas to the wafer 200, that is, the gas supply time (irradiation time) is, for example, 1 to 120 seconds, preferably 1 to 60 seconds. Other processing conditions are, for example, the same processing conditions as those in step 2 of the film forming sequence shown in FIG. Examples of the N-containing gas include NH ₃ gas, hydrogen nitride-based gases such as diazene (N ₂ H ₂ ) gas, hydrazine (N ₂ H ₄ ) gas, and N ₃ H ₈ gas, and compounds thereof. Gas or the like can be used.

In the step of supplying NH ₃ gas to the wafer 200 by plasma excitation, the supply flow rate of the NH ₃ gas controlled by the MFC 241b is set to a flow rate in the range of 100 to 10,000 sccm, for example. The RF power applied between the rod-shaped

electrodes

269 and 270 is, for example, power in the range of 50 to 1000 W. The pressure in the processing chamber 201 is, for example, 1 to 500 Pa, preferably 1 to 100 Pa. The partial pressure of NH ₃ gas in the processing chamber 201 is, for example, 0.01 to 495 Pa, preferably 0.01 to 99 Pa. By using plasma, the NH ₃ gas can be activated even when the pressure in the processing chamber 201 is set to such a relatively low pressure zone. Other processing conditions are, for example, the same processing conditions as those in step 2 of the film forming sequence shown in FIG. As the N-containing gas, in addition to NH ₃ gas, the above-mentioned various hydrogen nitride-based gases, gases containing these compounds, and the like can be used.

Further, in the step of supplying the C ₃ H ₆ gas to the wafer 200, the supply flow rate of the C ₃ H ₆ gas controlled by the MFC 241b is set to a flow rate in the range of 100 to 10,000 sccm, for example. The pressure in the processing chamber 201 is, for example, 1 to 5000 Pa, preferably 1 to 4000 Pa. In addition, the partial pressure of the C ₃ H ₆ gas in the processing chamber 201 is set to a pressure in the range of 0.01 to 4950 Pa, for example. The time for supplying the C ₃ H ₆ gas to the wafer 200, that is, the gas supply time (irradiation time) is, for example, in the range of 1 to 200 seconds, preferably 1 to 120 seconds, more preferably 1 to 60 seconds. Time. Other processing conditions are, for example, the same processing conditions as those in step 2 of the film forming sequence shown in FIG. As the C-containing gas, in addition to C ₃ H ₆ gas, for example, hydrocarbon gas such as acetylene (C ₂ H ₂ ) gas, ethylene (C ₂ H ₄ ) gas and the like can be used.

The processing procedures and processing conditions in other steps can be the same as the processing procedures and processing conditions of each step in the film forming sequence shown in FIG.

<Other Embodiments of the Present Invention>
The embodiment of the present invention has been specifically described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

For example, in the above-described embodiment, the example in which the reaction gas (B-containing gas, N-containing gas gas, C-containing gas) is supplied after the source gas is supplied has been described. The present invention is not limited to such a form, and the supply order of the source gas and the reaction gas may be reversed. That is, the source gas may be supplied after the reaction gas is supplied. By changing the supply sequence, the film quality and composition ratio of the thin film to be formed can be changed. Further, the supply order of the plural kinds of reaction gases can be arbitrarily changed. By changing the supply sequence of the reaction gas, the film quality and composition ratio of the formed thin film can be changed.

For example, in the above-described embodiment, an example in which TMB gas that is an organic borazine-based gas is used as the first B-containing gas has been described. The present invention is not limited to such a form, and a C-free borazine-based gas such as borazine (B ₃ H ₆ N ₃ ) gas, for example, an inorganic borazine-based gas is used as the first B-containing gas. You may do it. In the film forming sequence shown in FIG. 4, when an inorganic borazine-based gas is used as the second B-containing gas, a C-free film having a borazine ring skeleton and containing Si, B, and N on the wafer 200, That is, a C-free SiBN film containing a borazine ring skeleton is formed.

By using the silicon-based insulating film formed by the film forming sequence shown in FIG. 4 and the method of each modification as a side wall spacer, it is possible to provide a device forming technique with low leakage current and excellent workability. It becomes. In addition, by using the above-described silicon-based insulating film as an etch stopper, it is possible to provide a device forming technique with excellent workability. Further, according to the film forming sequence shown in FIG. 4 and each modification, it is possible to form a silicon-based insulating film having an ideal stoichiometric ratio without using plasma. Since a silicon-based insulating film can be formed without using plasma, it is possible to adapt to a process that is concerned about plasma damage, such as a DPT SADP film.

In the above-described film formation sequence, titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), aluminum (Al), molybdenum (Mo), and tungsten (W The present invention can also be suitably applied to the case of forming a boronitride film having a borazine ring skeleton and a metal element, that is, a metal boronitride film including a borazine ring skeleton.

That is, the present invention includes, for example, a TiBN film, a TiBCN film, a ZrBN film, a ZrBCN film, an HfBN film, an HfBCN film, a TaBN film, a TaBCN film, an NbBN film, an NbBCN film, an AlBN film, an AlBCN film, an MoBN film, an MoBCN film, The present invention can also be suitably applied when forming a metal-based boronitride film including a borazine ring skeleton such as a WBN film or a WBCN film.

In these cases, a source gas containing a metal element can be used as the source gas instead of the source gas containing a semiconductor element such as Si in the above-described embodiment. As the reaction gas, the same gas as in the above-described embodiment can be used. The processing procedure and processing conditions at this time can be the same processing procedure and processing conditions as in the above-described embodiment, for example.

That is, the present invention can be suitably applied when forming a boronitride film having a borazine ring skeleton and containing a predetermined element such as a semiconductor element or a metal element.

The process recipes (programs describing the processing procedures and processing conditions for substrate processing) used to form these various thin films are the contents of the substrate processing (film type, composition ratio, film quality, film thickness, processing of the thin film to be formed) According to the procedure, processing conditions, etc.), it is preferable to prepare each separately (preparing a plurality). And when starting a substrate processing, it is preferable to select a suitable recipe suitably from several recipes according to the content of a substrate processing. Specifically, a storage device included in the substrate processing apparatus stores a plurality of recipes individually prepared according to the contents of the substrate processing via an electric communication line or a recording medium (external storage device 123) that records the recipe. It is preferable to store (install) in 121c in advance. When starting the substrate processing, it is preferable that the CPU 121a included in the substrate processing apparatus appropriately selects an appropriate recipe from a plurality of recipes stored in the storage device 121c according to the content of the substrate processing. . With such a configuration, thin films having various film types, composition ratios, film qualities, and film thicknesses can be formed for general use with good reproducibility using a single substrate processing apparatus. In addition, it is possible to reduce the operation burden on the operator (such as an input burden on the processing procedure and processing conditions), and to quickly start the substrate processing while avoiding an operation error.

The above-described process recipe is not limited to a case of newly creating, and may be prepared by changing an existing recipe that has already been installed in the substrate processing apparatus, for example. When changing the recipe, the changed recipe may be installed in the substrate processing apparatus via an electric communication line or a recording medium on which the recipe is recorded. Further, an existing recipe that has already been installed in the substrate processing apparatus may be directly changed by operating the input / output device 122 provided in the existing substrate processing apparatus.

In the above-described embodiment, an example in which a thin film is formed using a batch-type substrate processing apparatus that processes a plurality of substrates at a time has been described. The present invention is not limited to the above-described embodiment, and can be suitably applied to the case where a thin film is formed using, for example, a single-wafer type substrate processing apparatus that processes one or several substrates at a time. In the above-described embodiment, an example in which a thin film is formed using a substrate processing apparatus having a hot wall type processing furnace has been described. The present invention is not limited to the above-described embodiment, and can also be suitably applied to the case where a thin film is formed using a substrate processing apparatus having a cold wall type processing furnace. Also in these cases, the processing procedure and processing conditions can be the same processing procedure and processing conditions as in the above-described embodiment, for example.

For example, the present invention can also be suitably applied when a film is formed using a substrate processing apparatus including the processing furnace 302 shown in FIG. The processing furnace 302 includes a processing container 303 that forms the processing chamber 301, a shower head 303s as a gas supply unit that supplies gas into the processing chamber 301 in a shower shape, and one or several wafers 200 in a horizontal posture. A support base 317 for supporting, a rotating shaft 355 for supporting the support base 317 from below, and a heater 307 provided on the support base 317 are provided. A gas supply port 332a for supplying the above-described source gas and a gas supply port 332b for supplying the above-described reaction gas are connected to an inlet (gas introduction port) of the shower head 303s. A gas supply system similar to the source gas supply system of the above-described embodiment is connected to the gas supply port 332a. Connected to the gas supply port 332b is a remote plasma unit (plasma generator) 339b serving as an excitation unit that supplies the above-described reaction gas by plasma excitation, and a gas supply system similar to the reaction gas supply system of the above-described embodiment. Has been. At the outlet (gas outlet) of the shower head 303s, a gas dispersion plate that supplies gas into the processing chamber 301 in a shower shape is provided. The shower head 303 s is provided at a position facing (facing) the surface of the wafer 200 carried into the processing chamber 301. The processing vessel 303 is provided with an exhaust port 331 for exhausting the inside of the processing chamber 301. An exhaust system similar to the exhaust system of the above-described embodiment is connected to the exhaust port 331.

For example, the present invention can also be suitably applied to the case where a film is formed using a substrate processing apparatus including the processing furnace 402 shown in FIG. The processing furnace 402 includes a processing container 403 that forms a processing chamber 401, a support base 417 that supports one or several wafers 200 in a horizontal position, a rotating shaft 455 that supports the support base 417 from below, and a processing container. A lamp heater 407 that irradiates light toward the wafer 200 in the 403 and a quartz window 403w that transmits light from the lamp heater 407 are provided. The processing container 403 is connected to a gas supply port 432a for supplying the above-described source gas and a gas supply port 432b as a gas supply unit for supplying the above-described reaction gas. A gas supply system similar to the source gas supply system of the above-described embodiment is connected to the gas supply port 432a. The gas supply port 432b is connected to the remote plasma unit 339b described above and a gas supply system similar to the reaction gas supply system of the above-described embodiment. The

gas supply ports

432a and 432b are respectively provided on the side of the end portion of the wafer 200 loaded into the processing chamber 401, that is, at a position not facing the surface of the wafer 200 loaded into the processing chamber 401. The processing container 403 is provided with an exhaust port 431 for exhausting the inside of the processing chamber 401. An exhaust system similar to the exhaust system of the above-described embodiment is connected to the exhaust port 431.

Even when these substrate processing apparatuses are used, film formation can be performed with the same sequence and processing conditions as those of the above-described embodiments and modifications.

Also, the above-described embodiments and modifications can be used in appropriate combination. Further, the processing conditions at this time can be the same processing conditions as in the above-described embodiment, for example.

<Preferred embodiment of the present invention>
Hereinafter, preferred embodiments of the present invention will be additionally described.

(Appendix 1)
According to one aspect of the invention,
Supplying a source gas containing a predetermined element and a halogen element to the substrate;
Supplying a first boron-containing gas containing a borazine ring skeleton to the substrate;
Supplying a second boron-containing gas not containing a borazine ring skeleton to the substrate;
Is performed a predetermined number of times under the condition that the borazine ring skeleton in the first boron-containing gas is retained, so that the substrate has the borazine ring skeleton, and the predetermined element, boron, and nitrogen A method for manufacturing a semiconductor device or a substrate processing method including a step of forming a film including the substrate is provided.

(Appendix 2)
The method according to appendix 1, preferably,
The step of supplying the first boron-containing gas and the step of supplying the second boron-containing gas are performed non-simultaneously.

(Appendix 3)
The method according to appendix 1, preferably,
The step of supplying the source gas, the step of supplying the first boron-containing gas, and the step of supplying the second boron-containing gas are performed non-simultaneously.

(Appendix 4)
The method according to appendix 1, preferably,
The step of supplying the first boron-containing gas and the step of supplying the second boron-containing gas are performed simultaneously.

(Appendix 5)
The method according to appendix 1, preferably,
Performing the step of supplying the source gas and the step of supplying the first boron-containing gas non-simultaneously;
The step of supplying the first boron-containing gas and the step of supplying the second boron-containing gas are performed simultaneously.

(Appendix 6)
The method according to any one of appendices 1 to 5, preferably,
The first boron-containing gas contains a borazine compound, and the second boron-containing gas contains a borane compound.

(Appendix 7)
The method according to any one of appendices 1 to 6, preferably,
The first boron-containing gas contains an organic borazine compound, and the second boron-containing gas contains an inorganic borane compound. That is, the first boron-containing gas contains a borazine compound containing an organic ligand, and the second boron-containing gas contains a borane compound containing no organic ligand. By using an organic borazine compound, carbon can be contained in the film.

(Appendix 8)
The method according to any one of appendices 1 to 7, preferably,
The first boron-containing gas contains a borazine compound containing an organic ligand, and the second boron-containing gas contains a borane compound containing a halogen element. That is, the second boron-containing gas contains a halogenated borane compound. By using a borazine compound containing an organic ligand, the film can contain carbon. The reaction efficiency can be increased by using a borazine compound containing an organic ligand and a borane compound containing a halogen element.

(Appendix 9)
The method according to any one of appendices 1 to 8, preferably,
The cycle further includes supplying a nitrogen-containing gas to the substrate. The step of supplying the nitrogen-containing gas can be performed non-simultaneously with the steps described above.

(Appendix 10)
The method according to any one of appendices 1 to 9, preferably,
The cycle further includes supplying a carbon-containing gas to the substrate. The step of supplying the carbon-containing gas can be performed non-simultaneously with the respective steps, or can be performed simultaneously with at least one of the steps. For example, the step of supplying the carbon-containing gas and the step of supplying the first boron-containing gas can be performed simultaneously.

(Appendix 11)
According to another aspect of the invention,
A processing chamber for accommodating the substrate;
A source gas supply system for supplying a source gas containing a predetermined element and a halogen element to the substrate in the processing chamber;
A first boron-containing gas supply system for supplying a first boron-containing gas containing a borazine ring skeleton to the substrate in the processing chamber;
A second boron-containing gas supply system that supplies a second boron-containing gas not containing a borazine ring skeleton to the substrate in the processing chamber;
A heater for heating the substrate in the processing chamber;
A pressure adjusting unit for adjusting the pressure in the processing chamber;
A process of supplying the source gas to the substrate in the processing chamber; a process of supplying the first boron-containing gas to the substrate in the processing chamber; and the first of the substrate in the processing chamber. A process including supplying a boron-containing gas of 2 under a condition that the borazine ring skeleton in the first boron-containing gas is maintained a predetermined number of times, whereby the borazine ring skeleton is formed on the substrate. The source gas supply system, the first boron-containing gas supply system, the second boron-containing gas supply system, and the heater so as to perform a process of forming a film containing the predetermined element, boron, and nitrogen. And a controller configured to control the pressure regulator;
A substrate processing apparatus is provided.

(Appendix 12)
According to yet another aspect of the invention,
A procedure for supplying a source gas containing a predetermined element and a halogen element to the substrate;
Supplying a first boron-containing gas containing a borazine ring skeleton to the substrate;
Supplying a second boron-containing gas containing no borazine ring skeleton to the substrate;
Is performed a predetermined number of times under the condition that the borazine ring skeleton in the first boron-containing gas is retained, so that the substrate has the borazine ring skeleton, and the predetermined element, boron, and nitrogen There is provided a program for causing a computer to execute a procedure for forming a film including the above, or a computer-readable recording medium on which the program is recorded.

121 Controller (control unit)
200 wafer (substrate)
201 processing chamber 202 processing furnace 203 reaction pipe 207 heater 231 exhaust pipe 232a to 232d gas supply pipe

Claims

Supplying a source gas containing a predetermined element and a halogen element to the substrate;
Supplying a first boron-containing gas containing a borazine ring skeleton to the substrate;
Supplying a second boron-containing gas not containing a borazine ring skeleton to the substrate;
Is performed a predetermined number of times under the condition that the borazine ring skeleton in the first boron-containing gas is retained, so that the substrate has the borazine ring skeleton, and the predetermined element, boron, and nitrogen A method for manufacturing a semiconductor device, comprising the step of forming a film including the same.
The method for manufacturing a semiconductor device according to claim 1, wherein the step of supplying the first boron-containing gas and the step of supplying the second boron-containing gas are performed simultaneously.
2. The method of manufacturing a semiconductor device according to claim 1, wherein the step of supplying the source gas, the step of supplying the first boron-containing gas, and the step of supplying the second boron-containing gas are performed simultaneously. .
2. The method of manufacturing a semiconductor device according to claim 1, wherein the step of supplying the first boron-containing gas and the step of supplying the second boron-containing gas are performed simultaneously.
Performing the step of supplying the source gas and the step of supplying the first boron-containing gas non-simultaneously;
The method for manufacturing a semiconductor device according to claim 1, wherein the step of supplying the first boron-containing gas and the step of supplying the second boron-containing gas are performed simultaneously.
2. The method of manufacturing a semiconductor device according to claim 1, wherein the first boron-containing gas contains a borazine compound, and the second boron-containing gas contains a borane compound.
2. The method of manufacturing a semiconductor device according to claim 1, wherein the first boron-containing gas contains an organic borazine compound, and the second boron-containing gas contains an inorganic borane compound.
2. The method of manufacturing a semiconductor device according to claim 1, wherein the first boron-containing gas contains a borazine compound containing an organic ligand, and the second boron-containing gas contains a borane compound containing a halogen element.
The method for manufacturing a semiconductor device according to claim 1, wherein the cycle further includes a step of supplying a nitrogen-containing gas to the substrate.
The method for manufacturing a semiconductor device according to claim 1, wherein the cycle further includes a step of supplying a carbon-containing gas to the substrate.
A processing chamber for accommodating the substrate;
A source gas supply system for supplying a source gas containing a predetermined element and a halogen element to the substrate in the processing chamber;
A first boron-containing gas supply system for supplying a first boron-containing gas containing a borazine ring skeleton to the substrate in the processing chamber;
A second boron-containing gas supply system that supplies a second boron-containing gas not containing a borazine ring skeleton to the substrate in the processing chamber;
A heater for heating the substrate in the processing chamber;
A pressure adjusting unit for adjusting the pressure in the processing chamber;
A process of supplying the source gas to the substrate in the processing chamber; a process of supplying the first boron-containing gas to the substrate in the processing chamber; and the first of the substrate in the processing chamber. And a step of supplying a boron-containing gas in a predetermined number of times under the condition that the borazine ring skeleton in the first boron-containing gas is retained, thereby forming a borazine ring skeleton on the substrate. The source gas supply system, the first boron-containing gas supply system, the second boron-containing gas supply system, and the heater so as to perform a process of forming a film containing the predetermined element, boron, and nitrogen. And a controller configured to control the pressure regulator;
A substrate processing apparatus.
A procedure for supplying a source gas containing a predetermined element and a halogen element to the substrate;
Supplying a first boron-containing gas containing a borazine ring skeleton to the substrate;
Supplying a second boron-containing gas containing no borazine ring skeleton to the substrate;
Is performed a predetermined number of times under the condition that the borazine ring skeleton in the first boron-containing gas is retained, so that the substrate has the borazine ring skeleton, and the predetermined element, boron, and nitrogen A computer-readable recording medium storing a program for causing a computer to execute a procedure for forming a film including