JP2005209766A - Method for manufacturing oxide film containing hafnium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an oxide film containing hafnium by which a fine and highly stickable film is obtained. <P>SOLUTION: The method is an improvement of a manufacturing method using an organic metal chemical vapor-phase growth. According to the manufacturing method, an organic hafnium compound is supplied to a vaporizing chamber 26 to be vaporized, and the vaporized organic hafnium compound is supplied to a deposition chamber 10 to be decomposed by heat. An oxygen source is supplied to the deposition chamber 10, where a heat decomposed material resulting from the vaporized organic hafnium is made to react with the oxygen source to form an oxide film containing hafnium on the surface of a base material 13 held in the film forming chamber 10. The improved method includes an additional process of supplying a nitrogen source further to either the vaporizing chamber 26 or the deposition chamber 10, or to both chambers 26, 10 where the supply ratio of the organic hafnium compound and the nitrogen source is 1:500 to 1:2,500 in terms of a weight ratio. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention relates to an HfO ₂ film, an Hf—Si—O film, an Hf—Si—O—N film, etc. formed by metal organic chemical vapor deposition (hereinafter referred to as MOCVD method). The present invention relates to a method for producing a hafnium-containing oxide film.

Although a silicon oxide film is used as the high dielectric gate insulating film, in recent years, the silicon oxide film is becoming thinner as the LSI is highly integrated. Since a tunnel current flows through a thin film having a thickness of 100 nm or less and the insulation effect is lowered, further reduction in the thickness of the silicon oxide film is limited.
Therefore, there is a demand for a gate insulating film that replaces the silicon oxide film. As a candidate, a hafnium-containing oxide film, specifically, a hafnium oxide film such as an HfO ₂ film, an Hf—Si—O film, or an Hf—Si—O—N film is used. A film and a hafnium silicon composite oxide film are attracting attention. Examples of the method for producing these hafnium-containing oxide films include MOD (Metal Organic Deposition) such as sputtering, ion plating, coating pyrolysis, sol-gel, etc., but are superior in composition controllability and step coverage as compared with the above production methods. In view of consistency with the semiconductor manufacturing process, the MOCVD method has been studied as an optimum film manufacturing process.
As a general method of manufacturing a hafnium oxide film using the MOCVD method, an organic hafnium compound is supplied to a decomposition reaction furnace with a carrier gas, and oxygen is simultaneously supplied to the decomposition reaction furnace as a reaction gas to contain hafnium. Forming on a substrate. (For example, refer to Patent Document 1).
JP 2002-93804 (paragraph numbers [0031] to [0035], FIG. 1)

  However, the hafnium oxide film obtained by the manufacturing method using a general MOCVD method as disclosed in Patent Document 1 has a problem that the film surface roughness is large and sufficient adhesion is not obtained. It was. In the subsequent device process, the product yield may be reduced due to these problems.

  An object of the present invention is to provide a method for producing a hafnium-containing oxide film from which a dense film having excellent adhesion can be obtained.

According to the first aspect of the present invention, an organic hafnium compound is supplied to a vaporization chamber to vaporize the organic hafnium compound, and the vaporized organic hafnium compound is supplied to the film formation chamber for thermal decomposition, and an oxygen source is supplied to the film formation chamber. To form a hafnium-containing oxide film on the surface of the substrate held in the film-forming chamber by reacting the thermal decomposition product of the organic hafnium compound with an oxygen source to cause hafnium-containing oxidation by metal organic chemical vapor deposition It is an improvement of the manufacturing method of the film. The characteristic configuration is that a nitrogen source is further supplied to one or both of the vaporization chamber and the film formation chamber, and the supply ratio of the organic hafnium compound and the nitrogen source is organic hafnium compound: nitrogen source = 1: 500 in volume ratio. It is in the range of -2500.
In the manufacturing method according to claim 1, by further supplying a nitrogen source at the above ratio to one or both of the vaporization chamber and the film formation chamber, the nitrogen source undergoes thermal decomposition, and N in the nitrogen source The bond is broken to form an active species. The active species is modified so as to cover the substrate surface to form a species that is easy to seed. As the organic hafnium compound molecules approach the active species, the active species modified on the surface of the substrate are released therefrom, so that a dense film with excellent adhesion can be formed.

The invention according to claim 2 is the invention according to claim 1, wherein the organic hafnium compound is a metal alkoxide compound represented by the following formula (1), and a cyclopentadienyl compound represented by the following formula (2): And a production method comprising one or more selected from the group consisting of a compound containing a β-diketone represented by the following formula (3), a halide and a compound containing a β-diketone represented by the following formula (4): It is.
Hf (O-R ¹ ) ₄ (1)
However, R ¹ is a straight-chain or branched alkyl group having 1 to 5 carbon atoms.

Hf (R ² Cp) _n X _(4-n) (2)
However, R ² is a straight-chain or branched alkyl group having 1 to 4 carbon hydrogen or carbon, Cp is a cyclopentadienyl group, X is F, Cl, Br or I, n is 1 to 4 Indicates an integer.

However, R ^3, R ⁴ or R ⁵ is a straight-chain or branched alkyl group having 1 to 4 carbon atoms, m represents an integer of 1-4, R ^3, R ⁴ and R ⁵ one is also in each identical Parts or all may be different.

However, R < ⁶ >, R < ⁷ >, R < ⁸ >, R < ⁹ > or R < ¹⁰ > is hydrogen or a C1-C4 linear or branched alkyl group, p shows the integer of 1-3, R < ⁶ >, R <^7> , R ⁸ , R ⁹ and R ¹⁰ may be the same or partly or wholly different.

The invention according to claim 3 is the method according to claim 1, wherein the nitrogen source includes one or more selected from the group consisting of NR ¹¹ R ¹² H and R ¹³ N = NR ^14. It is.
However, R ^11, R ^12, R ¹³ or R ¹⁴ is hydrogen, straight-chain or branched alkyl group having 1 to 6 carbon atoms, may be R ¹¹ and R ¹² are not the same as or different from each other, and R ¹³ R ¹⁴ may be the same or different.

The invention according to claim 4 is the invention according to claim 1, wherein a hafnium silicon composite oxide film is formed by further supplying an organic silicon compound.
In the manufacturing method according to claim 4, by further supplying an organic silicon compound, the hafnium silicon composite oxide film, specifically, the Hf—Si—O film or the Hf—Si—O—N film is densely and closely adhered. It can be formed as a film having excellent properties.

The invention according to claim 5 is the manufacturing method according to claim 4, wherein the organic silicon compound is represented by the following formula (5).
(R ¹⁵ R ¹⁶ N) _q SiH _(4-q) (5)
However, R < ¹⁵ >, R < ¹⁶ > is a C1-C4 linear or branched alkyl group, R <^15> and R < ¹⁶ > may mutually be same or different, and q is an integer of 1-4.

The invention according to claim 6 is the invention according to claim 5, wherein the organic silicon compound is (Et ₂ N) ₄ Si, (Et ₂ N) ₃ SiH, (Et ₂ N) ₂ SiH ₂ , (Me _2). N) ₄ Si, (Me ₂ N) ₃ SiH and (Me ₂ N) ₂ SiH ₂ .
However, Et is an ethyl group and Me is a methyl group.

The invention according to claim 7 is the invention according to claim 4, wherein the organic silicon compound is a production method represented by the following formula (6).
(R ¹⁷ R ¹⁸ N) _s R ¹⁹ _(4-s) Si—Si (R ²⁰ R ²¹ N) _t R ²² _(4-t) (6)
R ¹⁷ , R ¹⁸ , R ²⁰ or R ²¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, and R ¹⁷ and R ¹⁸ , R ²⁰ and R ²¹ may be the same or different from each other. , R ¹⁹ and R ²² are hydrogen or 1 to 4 linear or branched alkyl groups, and s and t are integers of 1 to 4.

The invention according to claim 8 is the invention according to claim 7, wherein the organosilicon compound is [(Et ₂ N) ₂ HSi—] ₂ , [(Et ₂ N) ₂ MeSi—] ₂ , [(Me ₂ N) ₂ HSi—] ₂ and [(Me ₂ N) ₂ MeSi—] ₂ .
However, Et is an ethyl group and Me is a methyl group.

The invention according to claim 9 is the manufacturing method according to claim 4, wherein the organic silicon compound is Si (O—R ²³ ) ₄ .
However, R ²³ is a straight-chain or branched alkyl group having 1 to 4 carbon atoms.

  As described above, the method for producing a hafnium-containing oxide film according to the present invention supplies an organic hafnium compound to a vaporization chamber to vaporize the organic hafnium compound, and supplies the vaporized organic hafnium compound to the film formation chamber to heat. A method of forming a hafnium-containing oxide film on the surface of a substrate held in a film formation chamber by decomposing and supplying an oxygen source to the film formation chamber to react a thermal decomposition product of an organic hafnium compound with the oxygen source The nitrogen source is further supplied to one or both of the vaporization chamber and the film formation chamber, and the supply ratio of the organic hafnium compound and the nitrogen source is organic hafnium compound: nitrogen source = 1: 500 to volume ratio. By making it within the range of 2500, this nitrogen source undergoes thermal decomposition, and the bond is broken by N in the nitrogen source to form an active species, and the active species is modified to cover the substrate surface. To form what is easy seeded Te. When the organic hafnium compound molecules approach the substrate, the active species modified on the substrate surface is released therefrom, so that a dense film having excellent adhesion can be formed.

Next, the best mode for carrying out the present invention will be described with reference to the drawings.
The method for producing a hafnium-containing oxide film by the MOCVD method of the present invention supplies an organic hafnium compound to a vaporizing chamber to vaporize the organic hafnium compound, and supplies the vaporized organic hafnium compound to the film forming chamber for thermal decomposition. By improving the method of forming a hafnium-containing oxide film on the surface of the substrate held in the film forming chamber by supplying an oxygen source to the film forming chamber and reacting the thermal decomposition product of the organic hafnium compound with the oxygen source. is there. The characteristic configuration is that a nitrogen source is further supplied to one or both of the vaporization chamber and the film formation chamber, and the supply ratio of the organic hafnium compound and the nitrogen source is organic hafnium compound: nitrogen source = 1: 500 in volume ratio. It is in the range of -2500. By further supplying a nitrogen source at one or both of the vaporization chamber and the film formation chamber at the above supply rate, this nitrogen source undergoes thermal decomposition, and the bonds are cut by N in the nitrogen source, so that the active species are removed. It is formed. The active species is modified so as to cover the substrate surface to form a species that is easy to seed. When the organic hafnium compound molecules approach the substrate, the active species modified on the substrate surface is released therefrom, so that a dense film having excellent adhesion can be formed.

  The supply ratio is such that the supply ratio of the organic hafnium compound and the nitrogen source is in the range of organic hafnium compound: nitrogen source = 1: 500 to 2500 in volume ratio. When the supply ratio is less than 1: 500, active species due to the nitrogen source are not sufficiently formed, so that the resulting hafnium-containing oxide film is liable to be peeled off. When the supply ratio exceeds 1: 2500, the nitrogen source As a result, excessively supplied active species are caused, resulting in a nonuniform surface of the obtained hafnium-containing oxide film. A preferred feed ratio is 1: 1.000 to 1500, and a particularly preferred feed ratio is 1: 1250-1500.

  In the production method of the present invention, particularly suitable organic hafnium compounds include metal alkoxide compounds represented by the following formula (1), cyclopentadienyl compounds represented by the following formula (2), and the following formula (3 1) or 2 or more types selected from the group consisting of a compound containing a β-diketone represented by formula (4), a halide, and a compound containing a β-diketone represented by the following formula (4).

Hf (O-R ¹ ) ₄ (1)
However, R ¹ is a straight-chain or branched alkyl group having 1 to 5 carbon atoms.

Hf (R ² Cp) _n X _(4-n) (2)
However, R ² is a straight-chain or branched alkyl group having 1 to 4 carbon hydrogen or carbon, Cp is a cyclopentadienyl group, X is F, Cl, Br or I, n is 1 to 4 Indicates an integer.

However, R ^3, R ⁴ or R ⁵ is a straight-chain or branched alkyl group having 1 to 4 carbon atoms, m represents an integer of 1-4, R ^3, R ⁴ and R ⁵ one is also in each identical Parts or all may be different.

However, R < ⁶ >, R < ⁷ >, R < ⁸ >, R < ⁹ > or R < ¹⁰ > is hydrogen or a C1-C4 linear or branched alkyl group, p shows the integer of 1-3, R < ⁶ >, R <^7> , R ⁸ , R ⁹ and R ¹⁰ may be the same or partly or wholly different.

The reason why R ¹ in the metal alkoxide compound represented by the above formula (1) is defined as a linear or branched alkyl group having 1 to 5 carbon atoms is an alkyl group having 6 or more carbon atoms, This is because the reactivity becomes too high, the substrate interaction becomes weak and the peelability is generated, or the particle size is not uniform and the surface becomes uneven.
Examples of the metal alkoxide compound represented by the above formula (1) are Hf (O-Me) ₄ , Hf (O-Et) ₄ , Hf (O-nPr) ₄ , Hf (O-iPr) ₄ , Hf (O-nBu) ₄ , Hf (O-iBu) ₄ , Hf (O-sBu) ₄ , Hf (O-tBu) ₄ , Hf (O-nPet) ₄ , Hf (O-iPet) ₄ , Hf ( O-tPet) _{4 and the} like.

The reason why R ² in the cyclopentadienyl compound represented by the above formula (2) is defined as a linear or branched alkyl group having 1 to 4 carbon atoms is an alkyl group having 5 or more carbon atoms, This is because the reactivity with the substrate becomes too high, and the substrate interaction becomes weak, causing releasability, and the particle size is not uniform, so that the surface becomes uneven.
Examples of the cyclopentadienyl compound represented by the above formula (2) are Hf (Cp) ₄ , Hf (MeCp) ₄ , Hf (EtCp) ₄ , Hf (nPrCp) ₄ , Hf (iPrCp) ₄ , Hf (nBuCp) ₄ , Hf (iBuCp) ₄ , Hf (sBuCp) ₄ , Hf (tBuCp) ₄ , Hf (Cp) Cl ₃ , Hf (MeCp) Cl ₃ , Hf (EtCp) Cl ₃ , Hf (nPrCp) Cl ₃ , Hf (iPrCp) Cl ₃ , Hf (nBuCp) Cl ₃ , Hf (iBuCp) Cl ₃ , Hf (sBuCp) Cl ₃ , Hf (tBuCp) Cl ₃ , Hf (Cp) ₂ Cl ₂ , Hf (MeCp) ₂ Cl ₂ , Hf (EtCp) ₂ Cl ₂ , Hf (nPrCp) ₂ Cl ₂ , Hf (iPrCp) ₂ Cl ₂ , Hf (nBuCp) ₂ Cl ₂ , Hf (iBuCp) ₂ Cl ₂ , Hf (sBuCp) ₂ Cl _{2, Hf (tBuCp) 2 Cl} 2, Hf (Cp) 3 C _{, Hf (MeCp) 3 Cl,} Hf (EtCp) 3 Cl, Hf (nPrCp) 3 Cl, Hf (iPrCp) 3 Cl, Hf (nBuCp) 3 Cl, Hf (iBuCp) 3 Cl, Hf (sBuCp) 3 Cl, Hf (tBuCp) ₃ Cl and the like can be mentioned.

R ³ , R ⁴ , and R ⁵ in the compound containing a β-diketone represented by the above formula (3) are defined as a linear or branched alkyl group having 1 to 4 carbon atoms. If it is a group, the reactivity with the substrate becomes too high, the substrate interaction becomes weak, causing releasability, and the particle size is not uniform, so that the surface becomes uneven.
Examples of a compound containing a β-diketone represented by the above formula (3) include Hf (HD) ₄ , Hf (DMHD) ₄ , Hf (DMND) ₄ , Hf (DMDD) ₄ , Hf (DPM) ₄ , Hf (DMHD) ₃ (O-Me), Hf (DPM) ₃ (O-Me), Hf (DMHD) ₂ (O-Me) ₂ , Hf (DPM) ₂ (O-Me) ₂ , Hf (DMHD) (O-Me) ₃ , Hf (DPM) (O-Me) ₃ , Hf (DMHD) ₃ (O-Et), Hf (DPM) ₃ (O-Et), Hf (DMHD) ₂ (O-Et) ₂ , Hf (DPM) ₂ (O-Et) ₂ , Hf (DMHD) (O-Et) ₃ , Hf (DPM) (O-Et) ₃ , Hf (DMHD) ₃ (O-nPr), Hf (DPM) ) ₃ (O-nPr), Hf (DMHD) ₂ (O-nPr) ₂ , Hf (DPM) ₂ (O-nPr) ₂ , Hf (DMHD) (O-nPr) ₃ , Hf (DPM) (O− _{nPr) 3, Hf (DMHD)} 3 (O-iPr), Hf (DPM) 3 (O-iPr), Hf (D _{HD) 2 (O-iPr)} 2, Hf (DPM) 2 (O-iPr) 2, Hf (DMHD) (O-iPr) 3, Hf (DPM) (O-iPr) 3, Hf (DMHD) 3 ( O-nBu), Hf (DPM) ₃ (O-nBu), Hf (DMHD) ₂ (O-nBu) ₂ , Hf (DPM) ₂ (O-nBu) ₂ , Hf (DMHD) (O-nBu) ₃ Hf (DPM) (O-nBu) ₃ , Hf (DMHD) ₃ (O-iBu), Hf (DPM) ₃ (O-iBu), Hf (DMHD) ₂ (O-iBu) ₂ , Hf (DPM) ₂ (O-iBu) ₂ , Hf (DMHD) (O-iBu) ₃ , Hf (DPM) (O-iBu) ₃ , Hf (DMHD) ₃ (O-tBu), Hf (DPM) ₃ (O-tBu ), Hf (DMHD) ₂ (O-tBu) ₂ , Hf (DPM) ₂ (O-tBu) ₂ , Hf (DMHD) (O-tBu) ₃ , Hf (DPM) (O-tBu) _3, etc. It is done. To illustrate halides include _{HfF 4, HfCl 4, HfBr 4} , HfI 4.

R ⁶ , R ⁷ , R ⁸ , R ⁹ , and R ¹⁰ in the compound containing a β-diketone represented by the above formula (4) are defined as a linear or branched alkyl group having 1 to 4 carbon atoms. If the number of alkyl groups is 5 or more, the reactivity with the substrate becomes too high, and the substrate interaction becomes weak and peelability occurs, or the particle size is not uniform and the surface becomes uneven. This is because it occurs.
Examples of a part of a compound containing a β-diketone represented by the above formula (4) include Hf (DMHD) (O—C (Me) H—O—Me) ₃ , Hf (DMHD) (O—C (Me) (Et) -O-Me) ₃ , Hf (DMHD) (O—C (Me) (iPr) -O-Me) ₃ , Hf (DMHD) (O—C (tBu) ₂ —O-Me) ₃ , Hf (DMHD) ₂ (O—C (Me) H—O—Me) ₂ , Hf (DMHD) ₂ (O—C (Me) (Et) —O—Me) ₂ , Hf (DMHD) ₂ (O— C (Me) (iPr) -O-Me) ₂ , Hf (DMHD) ₂ (O—C (tBu) ₂ —O-Me) ₂ , Hf (DMHD) ₃ (O—C (Me) H—O— Me), Hf (DMHD) ₃ (O—C (Me) (Et) —O—Me), Hf (DMHD) ₃ (O—C (Me) (iPr) —O—Me), Hf (DMHD) ₃ (O—C (tBu) ₂ —O—Me), Hf (DPM) (O—C (Me) H—O—Me) ₃ , Hf (DPM) (O—C (Me) (Et) —O— Me) ₃ , Hf (DPM) (O—C (Me) (iPr) —O) -Me) ₃ , Hf (DPM) (O-C (tBu) ₂ -O-Me) ₃ , Hf (DPM) ₂ (O-C (Me) H-O-Me) ₂ , Hf (DPM) ₂ ( O—C (Me) (Et) —O—Me) ₂ , Hf (DPM) ₂ (O—C (Me) (iPr) —O—Me) ₂ , Hf (DPM) ₂ (O—C (tBu) ₂ -O-Me) ₂ , Hf (DPM) ₃ (O-C (Me) H-O-Me), Hf (DPM) ₃ (O-C (Me) (Et) -O-Me), Hf ( DPM) ₃ (O—C (Me) (iPr) —O—Me), Hf (DPM) ₃ (O—C (tBu) ₂ —O—Me), and the like.

In the production method of the present invention, particularly suitable oxygen sources include O ₂ gas and O ₃ gas.
In the production method of the present invention, particularly suitable nitrogen sources include one or more selected from the group consisting of NR ¹¹ R ¹² H and R ¹³ N═NR ¹⁴ . However, R ^11, R ^12, R ¹³ or R ¹⁴ is hydrogen, straight-chain or branched alkyl group having 1 to 6 carbon atoms, may be R ¹¹ and R ¹² are not the same as or different from each other, and R ¹³ R ¹⁴ may be the same or different.

The reason why R ¹¹ and R ¹² in NR ¹¹ R ¹² H are defined as a linear or branched alkyl group having 1 to 6 carbon atoms is that the alkyl group having 7 or more carbon atoms has reactivity with the substrate. This is because it becomes too high and the substrate interaction is weakened to cause releasability, or the surface is not uniform because the particle size is not uniform.
Some examples of NR ¹¹ R ¹² H compounds are NH ₃ , N (Me) ₂ H, N (Et) ₂ H, N (nPr) ₂ H, N (iPr) ₂ H, N (nBu) ₂ H, N (iBu) ₂ H, N (sBu) ₂ H, N (tBu) ₂ H, N (nPet) ₂ H, N (iPet) ₂ H, N (tPet) ₂ H, N (nHex) ₂ H N (Me) H ₂ , N (Et) H ₂ , N (Me) (Et) H, N (iPr) H ₂ , N (Me) (iPr) H, N (Et) (iPr) H, N (tBu) H ₂ , N (Me) (tBu) H, N (Et) (tBu) H, N (iPr) (tBu) H, N (iPet) H ₂ , N (Me) (iPet) H, N (Et) (iPet) H, N (iPr) (iPet) H, N (tBu) (iPet) H, N (nHex) H ₂ , N (Me) (nHex) H, N (Et) (nHex) H N (iPr) (nHex) H, N (tBu) (nHex) H, N (iPet) (nHex) H, N (tPet) (nHex) H, etc. It is below.

The reason why R ¹³ and R ¹⁴ in R ¹³ N = NR ¹⁴ are defined as a linear or branched alkyl group having 1 to 6 carbon atoms is that the alkyl group having 7 or more carbon atoms is reactive with the substrate. This is because the film becomes too high, and the substrate interaction becomes weak to cause peelability, and the particle size is not uniform, resulting in a problem that the surface becomes non-uniform.
Some examples of compounds of R ¹³ N═NR ¹⁴ are HN = NH, HN = NMe, HN = NEt, HN = N (iPr), HN = N (tBu), HN = N (iPet), HN = N (nHex), MeN = NMe, MeN = NEt, MeN = N (iPr), MeN = N (tBu), MeN = N (iPet), MeN = N (nHex), EtN = NEt, EtN = N (iPr ), EtN = N (tBu), EtN = N (iPet), EtN = N (nHex), (iPr) N = N (iPr), (iPr) N = N (tBu), (iPr) N = N ( iPet), (iPr) N = N (nHex), (tBu) N = N (tBu), (tBu) N = N (nPet), (tBu) N = N (iPet), (tBu) N = N ( tPet), (tBu) N = N (nHex), (iPet) N = N (iPet), (iPet) N = N (tPet), (iPet) N = N (nHex), (nHex) N = N ( nHex) and the like.

In the manufacturing method of the present invention, a hafnium silicon composite oxide film such as a Si—O—Hf thin film can be formed by further supplying an organic silicon compound.
A general formula of a suitable organosilicon compound is represented by the following formula (5).
(R ¹⁵ R ¹⁶ N) _q SiH _(4-q) (5)
R ¹⁵ and R ^{16 in} the above formula (5) are linear or branched alkyl groups having 1 to 4 carbon atoms, R ¹⁵ and R ¹⁶ may be the same or different, and q is an integer of 1 to 4. It is. Examples of the alkyl group for R ¹⁵ and R ¹⁶ include a Me group, an Et group, a Pr group, and a Bu group. Examples of the organic silicon compound represented by the general formula (5) include (Et ₂ N) ₄ Si, (Et ₂ N) ₃ SiH, (Et ₂ N) ₂ SiH ₂ , (Me ₂ N) ₄ Si, (Me ₂ N) ₃ SiH and (Me ₂ N) ₂ SiH ₂ . The organosilicon compound may be a compound represented by the following formula (6).
(R ¹⁷ R ¹⁸ N) _s R ¹⁹ _(4-s) Si—Si (R ²⁰ R ²¹ N) _t R ²² _(4-t) (6)
R ¹⁷ , R ¹⁸ , R ²⁰ or R ^{21 in the} formula (6) is a linear or branched alkyl group having 1 to 4 carbon atoms, and R ¹⁷ and R ¹⁸ , R ²⁰ and R ²¹ are the same or different from each other. R ¹⁹ and R ²² are hydrogen or 1 to 4 linear or branched alkyl groups, and s and t are integers of 1 to 4. Examples of the alkyl group for R ¹⁷ , R ¹⁸ , R ²⁰ or R ²¹ include a Me group, an Et group, a Pr group, and a Bu group. Examples of the alkyl group for R ¹⁹ and R ²² include a Me group, an Et group, a Pr group, and a Bu group. Examples of the organic silicon compound represented by the general formula (6) include [(Et ₂ N) ₂ HSi—] ₂ , [(Et ₂ N) ₂ MeSi—] ₂ , [(Me ₂ N) ₂ HSi—] _2. And [(Me ₂ N) ₂ MeSi-] ₂ . Furthermore, the organic silicon compound may be a compound represented by Si (O—R ²³ ) ₄ . In the above formula, R ²³ is a linear or branched alkyl group having 1 to 4 carbon atoms. Examples of the organic silicon compound represented by the general formula Si (O—R ²³ ) ₄ include Si (O—Me) ₄ , Si (O—Et) ₄ , Si (O—nPr) ₄ , and Si (O—iPr). ₄ , Si (O-nBu) ₄ , Si (O-iBu) ₄ , and Si (O-tBu) ₄ .

  In the production method of the present invention, the organic hafnium compound or the organic silicon compound described above may be dissolved in an organic solvent at a predetermined ratio to obtain a solution raw material. By dissolving in an organic solvent, an organic hafnium compound or an organic silicon compound can be more stably sent to a vaporization chamber or a film formation chamber, and as a result, the growth rate of a thin film in MOCVD is promoted. As the organic solvent, one selected from the group consisting of THF, methyl THF, n-octane, isooctane, hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, pyridine, lutidine, butyl acetate, amyl acetate, methyl acetate and ethyl acetate or Two or more solvents can be mentioned. In the production method of the present invention, the organic hafnium compound and the nitrogen source described above may be mixed at a predetermined ratio to obtain a mixed raw material solution. High-speed film formation is possible by using a mixed raw material solution.

Next, an example of forming an HfO ₂ thin film by a solution vaporization CVD method using a solution raw material in which an organic hafnium compound is dissolved in an organic solvent will be described. The solution vaporization CVD method is a method in which each solution is supplied to a heated vaporizer, where each solution raw material is instantaneously vaporized and sent to a film formation chamber to form a film on a substrate.
As shown in FIG. 1, the MOCVD apparatus includes a film formation chamber 10 and a vapor generator 11. A heater 12 is provided inside the film forming chamber 10, and a substrate 13 is held on the heater 12. The inside of the film forming chamber 10 is evacuated by a pipe 17 including a pressure sensor 14, a cold trap 15 and a needle valve 16. An oxygen source supply pipe 37 is connected to the film forming chamber 10 through a needle valve 36 and a gas flow rate adjusting device 34. The steam generator 11 is provided with a raw material container 18, and the raw material container 18 stores and seals the solution raw material of the present invention. A first carrier gas supply pipe 21 is connected to the raw material container 18 via a gas flow rate control device 19, and a supply pipe 22 is connected to the raw material container 18. The supply pipe 22 is provided with a needle valve 23 and a solution flow rate adjusting device 24, and the supply pipe 22 is connected to a vaporizer 26. A nitrogen source supply pipe 41 is connected to the vaporizer 26 via a needle valve 39 and a gas flow rate control device 38. A second carrier gas supply pipe 29 is connected to the vaporizer 26 via a needle valve 31 and a gas flow rate adjusting device 28. The vaporizer 26 is further connected to the film forming chamber 10 by a pipe 27. A gas drain 32 and a drain 33 are connected to the vaporizer 26, respectively.
In this apparatus, a first carrier gas made of an inert gas such as N ₂ , He, or Ar is supplied from the first carrier gas supply pipe 21 into the raw material container 18, and the raw material is supplied by the carrier gas pressure supplied to the raw material container 18. The solution raw material stored in the container 18 is conveyed to the vaporizer 26 via the supply pipe 22. A nitrogen source is supplied from the nitrogen source supply pipe 41 into the vaporizer 26. The organic hafnium compound vaporized by the vaporizer 26 and the nitrogen source are further fed into the film forming chamber 10 via the pipe 27 by the second carrier gas supplied from the second carrier gas supply pipe 28 to the vaporizer 26. Supplied. In the film forming chamber 10, the vapor of the nitrogen source is thermally decomposed to form active species, which are modified on the substrate surface. Further, the vapor of the organic hafnium compound is thermally decomposed and reacts with the oxygen source supplied from the oxygen source supply pipe 37 into the film forming chamber 10, thereby generating HfO ₂ . When the generated HfO ₂ approaches the heated substrate 13, the active species modified on the surface of the substrate are released therefrom, and HfO ₂ starts to be deposited from the released portion, so that the HfO ₂ thin film having high density and high adhesion is obtained. Is obtained.

  Further, as shown in FIG. 2, the nitrogen source supply pipe 41 may be connected to the film formation chamber 10 so that the nitrogen source is directly supplied into the film formation chamber 10.

Next, examples of the present invention will be described in detail together with comparative examples.
<Example 1>
First, Hf (O-tBu) ₄ was prepared as an organic hafnium compound, and the organic hafnium compound was dissolved in an organic solvent (THF) to prepare a 1.0 mol / L solution raw material. Further, NH ₃ was prepared as a nitrogen source, and O ₂ was prepared as an oxygen source.
Next, a silicon substrate was prepared, and this substrate was placed in the film forming chamber 10 of the MOCVD apparatus shown in FIG. Next, the temperature of the substrate 13 was set to 500 ° C., the temperature in the vaporization chamber 26 was set to 70 ° C., and the pressure in the film forming chamber 10 was set to about 1.33 × 10 ³ Pa (10 Torr). In addition, the oxygen source supplied into the film forming chamber 10 was adjusted to a supply amount of 100 ccm. Next, Ar gas was supplied as a first carrier gas into the raw material container 18 and supplied to the vaporization chamber 26 so that the supply amount of the organic hafnium compound solution raw material was 0.05 ccm. In addition, the supply amount of the nitrogen source was adjusted to 62.5 ccm and supplied to the vaporizing chamber 26. Further, the second carrier gas was supplied to the vaporizing chamber 26 and the organic hafnium compound solution raw material and nitrogen source vaporized in the vaporizing chamber 26 were supplied into the film forming chamber 10 to form hafnium oxide on the surface of the substrate 13. When the film formation time was 30 minutes, the substrate 13 was taken out from the film formation chamber 10 to obtain a silicon substrate on which a hafnium oxide thin film having a predetermined thickness was formed.

<Example 2>
A hafnium oxide thin film was formed in the same manner as in Example 1 except that Hf (O-iPr) ₄ was used as the organic hafnium compound, N (Me) ₂ H was used as the nitrogen source, and the nitrogen source supply amount was 50 ccm. A silicon substrate was obtained.
<Example 3>
A hafnium oxide thin film was formed in the same manner as in Example 1 except that Hf (Cp) ₄ was used as the organic hafnium compound, N (Me) (Et) H was used as the nitrogen source, and the supply amount of this nitrogen source was 25 ccm. A silicon substrate was obtained.
<Example 4>
A silicon substrate on which a hafnium oxide thin film was formed in the same manner as in Example 1 except that Hf (Cp) Cl ₃ was used as the organic hafnium compound, HN = NH was used as the nitrogen source, and the nitrogen source supply amount was 100 ccm. Obtained.
<Example 5>
A silicon substrate on which a hafnium oxide thin film was formed in the same manner as in Example 1 except that Hf (MeCp) ₂ Br ₂ was used as the organic hafnium compound, MeN = NMe was used as the nitrogen source, and the nitrogen source supply amount was 75 ccm. Got.

<Example 6>
A silicon substrate on which a hafnium oxide thin film was formed in the same manner as in Example 1 except that Hf (DPM) ₄ was used as the organic hafnium compound, NH ₃ was used as the nitrogen source, and the nitrogen source supply amount was 62.5 ccm. Obtained.
<Example 7>
Silicon on which a hafnium oxide thin film was formed in the same manner as in Example 1 except that Hf (DMHD) ₄ was used as the organic hafnium compound, N (Me) ₂ H was used as the nitrogen source, and the nitrogen source supply amount was 75 ccm. A substrate was obtained.
<Example 8>
A silicon substrate on which a hafnium oxide thin film was formed in the same manner as in Example 1 except that HfCl ₄ was used as the organic hafnium compound, N (Me) (Et) H was used as the nitrogen source, and the nitrogen source supply amount was 125 ccm. Got.
<Example 9>
A hafnium oxide thin film as in Example 1 except that Hf (DPM) ₂ (O-tBu) ₂ is used as the organic hafnium compound, HN = NH is used as the nitrogen source, and the nitrogen source supply amount is 62.5 ccm. A silicon substrate on which was formed was obtained.
<Example 10>
Example 1 except that Hf (DPM) (O—C (tBu) ₂ —O—Me) ₃ was used as the organic hafnium compound, MeN = NMe was used as the nitrogen source, and the nitrogen source supply amount was 100 ccm. Thus, a silicon substrate on which a hafnium oxide thin film was formed was obtained.

<Comparative Example 1>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 1 except that Hf (O-tBu) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative example 2>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 1 except that Hf (DPM) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative Example 3>
A silicon substrate having a hafnium oxide thin film formed thereon was obtained in the same manner as in Example 1 except that Hf (DMHD) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative example 4>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 1 except that HfCl ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative Example 5>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 1 except that Hf (Me ₂ N) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.

<Comparison test 1>
A peel test for examining adhesion using a silicon substrate on which a hafnium oxide thin film obtained in each of Examples 1 to 10 and Comparative Examples 1 to 5 is formed, an average grain size test for examining particle diameter, and a surface roughness are examined. An AFM analyzer test was conducted.
(1) Peel test The following peel test was performed on the hafnium oxide thin film formed on the flat portion of the substrate with a film formation time of 30 minutes. First, the hafnium oxide thin film after film formation was cut into a predetermined size using a cutter knife to create 100 cut squares. Next, an adhesive cellophane tape was adhered to the hafnium oxide thin film having the grids. Subsequently, the cellophane tape was peeled off from the thin film, and the number of the hafnium oxide thin film cut into 100 cells and peeled off with the cellophane tape and the number remaining on the substrate were examined.
(2) Average Grain Size Test The average particle diameter on the thin film surface of the hafnium oxide thin film on the substrate after film formation was measured from an SEM (scanning electron microscope) image.
(3), respectively measuring the surface high roughness most R _top and the lowest R _Bottom of the thin film surface hafnium oxide thin film on a substrate after an AFM analyzer test deposited using AFM (atomic force microscope) Analyzer The value obtained by calculating R _Top / R _Bottom was _defined as the surface roughness.

<Evaluation>
Table 1 shows the results of the peel test, the particle diameter and the surface roughness obtained per film formation time. The peel test indicates the number of remaining substrates per 100 cut grids.

  As is clear from Table 1, the hafnium oxide thin films obtained in Comparative Examples 1 to 5 obtained only a low numerical value in the peel test, resulting in slightly inferior adhesion. In addition, the average particle size was generally high, and the surface roughness was large. On the other hand, it was found that the hafnium oxide thin films obtained in Examples 1 to 10 had high numerical values in the peel test and had excellent adhesion. Moreover, both the average particle diameter and the surface roughness showed small numerical values, indicating that a dense film was obtained.

<Examples 11 to 20>
First, as in Examples 1 to 10, an organic hafnium compound was prepared, and a 1.0 mol / L solution raw material was prepared. Moreover, the nitrogen source and the oxygen source were prepared similarly to Examples 1-10, respectively. Further, tetrakisdimethylaminosilane (Si (DMA) ₄ ) was prepared as an organosilicon compound, and a 1.0 mol / L solution raw material of this Si (DMA) ₄ was prepared.
Next, a silicon substrate was prepared, and this substrate was placed in the film forming chamber 10 of the MOCVD apparatus shown in FIG. Next, the temperature of the substrate 13 was set to 600 ° C., the temperature in the vaporization chamber 26 was set to 70 ° C., and the pressure in the film forming chamber 10 was set to about 1.33 × 10 ³ Pa (10 Torr). In addition, the oxygen source supplied into the film forming chamber 10 was adjusted to a supply amount of 100 ccm. Next, Ar gas was supplied into the first raw material container 18 as the first carrier gas, and supplied to the vaporization chamber 26 so that the supply amount of the organic hafnium compound solution raw material was 0.05 ccm. Further, the supply amount of the nitrogen source was adjusted so as to be the ratio shown in the following Table 2 and supplied to the vaporizing chamber 26. Also, Ar gas was supplied as the second carrier gas into the second raw material container 42 and supplied to the vaporization chamber 26 so that the supply amount of the organic silicon compound solution raw material was 0.05 ccm. Further, the third carrier gas is supplied to the vaporizing chamber 26, and the organic hafnium compound solution raw material, the organic silicon compound solution raw material, and the nitrogen source vaporized in the vaporizing chamber 26 are supplied into the film forming chamber 10 to supply hafnium on the substrate surface. A silicon composite oxide thin film was formed. When the film formation time was 30 minutes, the substrate 13 was taken out from the film formation chamber 10 to obtain a silicon substrate on which a hafnium silicon composite oxide thin film having a predetermined thickness was formed.

<Comparative Example 6>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 11 except that Hf (O-tBu) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative Example 7>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 11 except that Hf (DPM) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative Example 8>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 11 except that Hf (DMHD) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative Example 9>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 11 except that HfCl ₄ was used as the organic hafnium compound and no nitrogen source was supplied.
<Comparative Example 10>
A silicon substrate on which a hafnium oxide thin film was formed was obtained in the same manner as in Example 11 except that Hf (Me ₂ N) ₄ was used as the organic hafnium compound and no nitrogen source was supplied.

<Comparison test 2>
A peel test for examining the adhesion using the silicon substrate on which the hafnium silicon composite oxide thin film obtained in each of Examples 11 to 20 and Comparative Examples 6 to 10 was formed, an average grain size test and a surface roughness for examining the particle diameter An AFM analyzer test was conducted to check the thickness.
(1) Peel test The following peel test was performed on the hafnium silicon composite oxide thin film formed on the flat portion of the substrate with a film formation time of 30 minutes. First, the hafnium-silicon composite oxide thin film after film formation was cut into a predetermined size using a cutter knife to create 100 cut squares. Next, an adhesive cellophane tape was adhered to the hafnium oxide thin film having the grids. Subsequently, the cellophane tape was peeled off from the thin film, and the number of the hafnium silicon composite oxide thin film cut into 100 cells and peeled off by the cellophane tape and the number remaining on the substrate were examined.
(2) Average Grain Size Test The average particle size on the thin film surface of the hafnium silicon composite oxide thin film on the substrate after film formation was measured from an SEM (scanning electron microscope) image.
(3) high surface roughness of the film surface hafnium silicon composite oxide thin film on a substrate after an AFM analyzer test deposited using AFM (atomic force microscope) analyzer most R _top and the lowest R _Bottom Was measured, and the value obtained by calculating R _Top / R _Bottom was _defined as the surface roughness.

<Evaluation>
Table 2 shows the results of the peel test, the particle diameter and the surface roughness obtained per film formation time. The peel test indicates the number of remaining substrates per 100 cut grids.

  As is clear from Table 2, the hafnium oxide thin films obtained in Comparative Examples 6 to 10 were only able to obtain a low numerical value in the peel test, resulting in slightly inferior adhesion. In addition, the average particle size was generally high, and the surface roughness was large. On the other hand, it was found that the hafnium oxide thin films obtained in Examples 11 to 20 had high numerical values in the peel test, and obtained excellent results in adhesion. Moreover, both the average particle diameter and the surface roughness showed small numerical values, indicating that a dense film was obtained.

Schematic of the MOCVD apparatus used for the manufacturing method of this invention. The schematic of the MOCVD apparatus which has another structure. Furthermore, the schematic of the MOCVD apparatus which has another structure.

Claims (9)

An organic hafnium compound is supplied to the vaporization chamber to vaporize the organic hafnium compound, and the vaporized organic hafnium compound is supplied to the film formation chamber for thermal decomposition, and an oxygen source is supplied to the film formation chamber for organic Method for producing hafnium-containing oxide film by metal organic chemical vapor deposition, in which a hafnium-containing oxide film is formed on a substrate surface held in the film-forming chamber by reacting a thermal decomposition product of a hafnium compound with an oxygen source In
A nitrogen source is further supplied to one or both of the vaporization chamber and the deposition chamber;
A method for producing a hafnium-containing oxide film, wherein the supply ratio of the organic hafnium compound and the nitrogen source is within the range of organic hafnium compound: nitrogen source = 1: 500 to 2500 in a volume ratio. A compound containing a metal alkoxide compound represented by the following formula (1), a cyclopentadienyl compound represented by the following formula (2), a β-diketone represented by the following formula (3), or a halide The manufacturing method of Claim 1 containing 1 type (s) or 2 or more types selected from the group which consists of a compound containing (beta) diketone shown by following Formula (4).
Hf (O-R ¹ ) ₄ (1)
However, R ¹ is a straight-chain or branched alkyl group having 1 to 5 carbon atoms.
Hf (R ² Cp) _n X _(4-n) (2)
However, R ² is a straight-chain or branched alkyl group having 1 to 4 carbon hydrogen or carbon, Cp is a cyclopentadienyl group, X is F, Cl, Br or I, n is 1 to 4 Indicates an integer.

However, R ^3, R ⁴ or R ⁵ is a straight-chain or branched alkyl group having 1 to 4 carbon atoms, m represents an integer of 1-4, R ^3, R ⁴ and R ⁵ one is also in each identical Parts or all may be different.

However, R < ⁶ >, R < ⁷ >, R < ⁸ >, R < ⁹ > or R < ¹⁰ > is hydrogen or a C1-C4 linear or branched alkyl group, p shows the integer of 1-3, R < ⁶ >, R <^7> , R ⁸ , R ⁹ and R ¹⁰ may be the same or partly or wholly different. Nitrogen source NR ¹¹ R ¹² H and R ¹³ N = The method of claim 1 further comprising one or more selected from the group consisting of NR ^14.
However, R ^11, R ^12, R ¹³ or R ¹⁴ is hydrogen, straight-chain or branched alkyl group having 1 to 6 carbon atoms, may be R ¹¹ and R ¹² are not the same as or different from each other, and R ¹³ R ¹⁴ may be the same or different.   The manufacturing method according to claim 1, wherein an organic silicon compound is further supplied to form a hafnium silicon composite oxide film. The manufacturing method of Claim 4 with which an organosilicon compound is shown by following Formula (5).
(R ¹⁵ R ¹⁶ N) _q SiH _(4-q) (5)
However, R < ¹⁵ >, R < ¹⁶ > is a C1-C4 linear or branched alkyl group, R <^15> and R < ¹⁶ > may mutually be same or different, and q is an integer of 1-4. Organosilicon compounds are (Et ₂ N) ₄ Si, (Et ₂ N) ₃ SiH, (Et ₂ N) ₂ SiH ₂ , (Me ₂ N) ₄ Si, (Me ₂ N) ₃ SiH and (Me ₂ N) The manufacturing method according to claim 5, which is ₂ SiH ₂ .
However, Et is an ethyl group and Me is a methyl group. The manufacturing method of Claim 4 with which an organosilicon compound is shown by following Formula (6).
(R ¹⁷ R ¹⁸ N) _s R ¹⁹ _(4-s) Si—Si (R ²⁰ R ²¹ N) _t R ²² _(4-t) (6)
R ¹⁷ , R ¹⁸ , R ²⁰ or R ²¹ is a linear or branched alkyl group having 1 to 4 carbon atoms, and R ¹⁷ and R ¹⁸ , R ²⁰ and R ²¹ may be the same or different from each other. , R ¹⁹ and R ²² are hydrogen or 1 to 4 linear or branched alkyl groups, and s and t are integers of 1 to 4. The organosilicon compounds are [(Et ₂ N) ₂ HSi-] ₂ , [(Et ₂ N) ₂ MeSi-] ₂ , [(Me ₂ N) ₂ HSi-] ₂ and [(Me ₂ N) ₂ MeSi-]. The production method according to claim 7, which is ₂ .
However, Et is an ethyl group and Me is a methyl group. The method according to claim ₄ , wherein the organosilicon compound is Si (O—R ²³ ) ₄ .
However, R ²³ is a straight-chain or branched alkyl group having 1 to 4 carbon atoms.

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