JP7199200B2 - SUBSTRATE PLACE, SUBSTRATE PROCESSING APPARATUS, AND SUBSTRATE PROCESSING METHOD - Google Patents

Description

The present disclosure relates to a substrate mounting table, a substrate processing apparatus, and a substrate processing method.

In Patent Document 1, a metal base and an electrostatic chuck for attracting a substrate are provided, and at least a portion of the base that contacts the electrostatic chuck is made of martensitic stainless steel or ferritic stainless steel. A substrate mounting table is disclosed. According to the substrate mounting table disclosed in Patent Document 1 and the substrate processing apparatus equipped with this substrate mounting table, damage to the electrostatic chuck due to the difference in thermal expansion between the base material and the electrostatic chuck can be prevented.

JP 2017-147278 A

INDUSTRIAL APPLICABILITY The present disclosure is advantageous in performing a process with high in-plane uniformity when performing an etching process or the like on a substrate for an FPD in the manufacturing process of a flat panel display (hereinafter referred to as "FPD"). A substrate table and a substrate processing apparatus are provided.

A substrate mounting table according to one aspect of the present disclosure includes:
A substrate mounting table on which the substrate is mounted and the temperature of which is controlled when the substrate is processed in the processing container,
a metal first plate that is divided into a plurality of temperature control areas via gaps;
a second metal plate in contact with the first plate and having a lower thermal conductivity than the first plate;
Each of the temperature control areas incorporates a temperature control unit that performs unique temperature control,
The first plate, which has a top surface for mounting the substrate, is mounted on the top surface of the second plate.

Advantageous Effects of Invention According to the present disclosure, it is possible to provide a substrate mounting table, a substrate processing apparatus, and a substrate processing method that perform processing with high in-plane uniformity when performing etching processing or the like on a substrate for FPD.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows an example of the board|substrate mounting table which concerns on embodiment, a substrate processing apparatus, and a substrate processing method. FIG. 2 is a cross-sectional view of the first plate taken along line II-II of FIG. 1; FIG. 4 is a plan view simulating an example of a first plate; FIG. 11 is a plan view simulating another example of the first plate; FIG. 11 is a plan view simulating still another example of the first plate; FIG. 11 is a plan view simulating still another example of the first plate; FIG. 11 is a plan view simulating still another example of the first plate; FIG. 4 is a side view of an example of a substrate mounting table model used in temperature analysis; FIG. 11 is a side view of another example of a substrate mounting table model used in temperature analysis; FIG. 4B is a cross-sectional view of the temperature adjustment plate model taken along the line CC in FIGS. 4A and 4B, showing an analysis temperature specific point. It is a figure which shows the correlation graph of the frequency|count of discharge, and electrode temperature. It is the figure which expanded the B section of FIG. 5A. FIG. 4 is a diagram simulating a plan view of a substrate mounting table used in an experiment for verifying etching rate and selectivity; 5 is a graph showing experimental results regarding the temperature dependence of the etching rate of a SiN film; 5 is a graph showing experimental results regarding the temperature dependence of the etching rate of an SiO film; 5 is a graph showing experimental results regarding the temperature dependence of the etching rate of a Si film; 4 is a graph showing experimental results regarding the temperature dependence of the SiO/Si selectivity;

A substrate mounting table, a substrate processing apparatus, and a substrate processing method according to embodiments of the present disclosure will be described below with reference to the accompanying drawings. In addition, in the present specification and drawings, substantially the same components may be denoted by the same reference numerals, thereby omitting duplicate descriptions.

[Embodiment]
<Substrate Mounting Table, Substrate Processing Apparatus, and Substrate Processing Method>
First, an example of a substrate processing apparatus and a substrate processing method according to an embodiment of the present disclosure, and a substrate mounting table that constitutes the substrate processing apparatus will be described with reference to FIGS. 1 and 2. FIG. Here, FIG. 1 is a cross-sectional view showing an example of the substrate mounting table and the substrate processing apparatus according to the embodiment. 2 is a view taken along line II-II in FIG. 1, which is a cross-sectional view of the first plate.

A substrate processing apparatus 100 shown in FIG. 1 uses an inductively coupled plasma (ICP) for performing various substrate processing methods on a substrate G, which is rectangular in plan view for FPD (hereinafter simply referred to as “substrate”). ) processing equipment. Glass is mainly used as the material of the substrate, and transparent synthetic resin may be used depending on the application. Here, the substrate processing includes etching processing, film formation processing using a CVD (Chemical Vapor Deposition) method, and the like. Examples of FPD include a liquid crystal display (LCD), an electroluminescence (EL), a plasma display panel (PDP), and the like. In addition, the planar dimensions of FPD substrates have been increasing with the transition of generations. It includes at least up to dimensions of the order of 2800 mm x 3000 mm of the generation. Further, the thickness of the substrate G is about 0.5 mm to several mm.

The substrate processing apparatus 100 shown in FIG. 1 includes a rectangular parallelepiped box-shaped processing container 10, a substrate mounting table 60 having a rectangular outer shape in a plan view and arranged in the processing container 10 on which a substrate G is mounted, and a controller. 90.

The processing container 10 is divided into upper and lower spaces by a dielectric plate 11. The upper space serves as an antenna container 12 forming an antenna chamber, and the lower space serves as a chamber 13 forming a processing chamber. In the processing container 10, a rectangular ring-shaped support frame 14 is disposed at a position that serves as a boundary between the chamber 13 and the antenna container 12 so as to protrude inside the processing container 10. The support frame 14 is provided with a dielectric plate. 11 is placed. The processing container 10 is grounded by a ground wire 13c.

The processing container 10 is made of metal such as aluminum, and the dielectric plate 11 is made of ceramics such as alumina (Al ₂ O ₃ ) or quartz.

A side wall 13a of the chamber 13 is provided with a loading/unloading port 13b for loading/unloading the substrate G into/from the chamber 13, and the loading/unloading port 13b can be opened and closed by a gate valve 20. As shown in FIG. A transfer chamber (neither shown) containing a transfer mechanism is adjacent to the chamber 13, and the gate valve 20 is controlled to open and close, and the substrate G is transferred in and out through the transfer port 13b by the transfer mechanism. .

In addition, a plurality of exhaust ports 13d are opened at the bottom of the chamber 13, a gas exhaust pipe 51 is connected to the exhaust ports 13d, and the gas exhaust pipe 51 is connected to an exhaust device 53 via an on-off valve 52. there is A gas exhaust section 50 is formed by the gas exhaust pipe 51 , the on-off valve 52 and the exhaust device 53 . The evacuation device 53 has a vacuum pump such as a turbomolecular pump, and can evacuate the inside of the chamber 13 to a predetermined degree of vacuum during the process. A pressure gauge (not shown) is installed at an appropriate location in the chamber 13 , and monitoring information from the pressure gauge is transmitted to the control section 90 .

A support beam for supporting the dielectric plate 11 is provided on the lower surface of the dielectric plate 11 , and the support beam also serves as a shower head 30 . The showerhead 30 is made of metal such as aluminum, and may be surface-treated by anodization. A horizontally extending gas flow path 31 is formed in the shower head 30 , and the gas flow path 31 has gas discharge holes extending downward to face the processing space S below the shower head 30 . 32 are in communication.

A gas supply pipe 41 communicating with the gas flow path 31 is connected to the upper surface of the shower head 30 and connected to a processing gas supply source 44 . An on-off valve 42 and a flow controller 43 such as a mass flow controller are interposed in the middle of the gas supply pipe 41 . A processing gas supply section 40 is formed by the gas supply pipe 41 , the opening/closing valve 42 , the flow controller 43 and the processing gas supply source 44 . The gas supply pipe 41 branches in the middle, and each branch pipe communicates with an on-off valve, a flow controller, and a processing gas supply source corresponding to the type of processing gas (not shown). In plasma processing, the processing gas supplied from the processing gas supply unit 40 is supplied to the shower head 30 through the gas supply pipe 41 and is discharged into the processing space S through the gas discharge holes 32 .

A high-frequency antenna 15 is arranged in the antenna container 12 . The high-frequency antenna 15 is formed by winding an antenna wire 15a made of a highly conductive metal such as copper or aluminum in a ring or spiral shape. For example, the annular antenna wire 15a may be arranged in multiples.

A feeder member 16 extending above the antenna container 12 is connected to a terminal of the antenna wire 15a. A feeder line 17 is connected to the upper end of the feeder member 16. The feeder line 17 is connected to a matching device 18 for impedance matching. is connected to the high-frequency power supply 19 via the . An induction electric field is formed in the chamber 13 by applying high-frequency power of, for example, 13.56 MHz from the high-frequency power supply 19 to the high-frequency antenna 15 . Due to this induced electric field, the processing gas supplied from the shower head 30 to the processing space S is plasmatized to generate inductively coupled plasma, and the substrate G is provided with ions and radicals in the plasma. The high-frequency power supply 19 is a source for plasma generation, and as will be described in detail below, a high-frequency power supply 73 (an example of a power supply) connected to the substrate mounting table 60 is a bias that attracts the generated ions and imparts kinetic energy. source. In this manner, plasma is generated in the ion source using inductive coupling, and the bias source, which is a separate power source, is connected to the substrate mounting table 60 to control the ion energy. are independently controlled, and the degree of freedom of the process can be increased. The frequency of the high frequency power output from the high frequency power supply 19 is preferably set within the range of 0.1 to 500 MHz.

Next, the substrate mounting table 60 will be described. As shown in FIG. 1, the substrate mounting table 60 includes a metal first plate 61 divided into a plurality of temperature control areas 61a and 61b, and a single metal plate in contact with each of the temperature control areas 61a and 61b. and a second plate 63 of The temperature control areas 61a and 61b forming the first plate 61 are divided into areas via a gap 66, and the temperature control areas 61a and 61b are continuous at upper and lower positions of the gap 66. As shown in FIG. That is, the gap 66 forms a cavity inside the first plate 61 . A second plate 63 is connected to the lower surface of the first plate 61 .

The first plate 61 has a rectangular shape in plan view, and has approximately the same planar dimensions as the FPD mounted on the substrate mounting table 60 . For example, the first plate 61 shown in FIG. 2 has the same planar dimensions as the substrate G to be mounted, the long side length t2 is about 1800 mm to 3000 mm, and the short side length t3 is 1500 mm. It can be set to a dimension of about 2800 mm. For this planar dimension, the total thickness of the first plate 61 and the second plate 63 can be, for example, about 50 mm to 100 mm.

A second plate 63 arranged below the first plate 61 is a metal plate having a lower thermal conductivity than the first plate 61 . For example, the first plate 61 is made of aluminum or an aluminum alloy. On the other hand, the second plate 63 is made of stainless steel.

Aluminum, which is the material for forming the first plate 61, is a metal material with high thermal conductivity, and JIS standards include A5052, A6061, A1100, and the like. A5052 has a thermal conductivity of 138 W/m·K, A6061 has a thermal conductivity of 180 W/m·K, and A1100 has a thermal conductivity of 220 W/m·K.

On the other hand, stainless steel, which is the material for forming the second plate 63, is a metal material with low thermal conductivity. Stainless steel includes martensitic stainless steel, ferritic stainless steel, and austenitic stainless steel.

The martensitic stainless steel has a metal structure mainly composed of a martensite phase, and SUS403, SUS410, SUS420J1, and SUS420J2 are suitable as JIS standards. Other martensitic stainless steels include SUS410S, SUS440A, SUS410F2, SUS416, SUS420F2 and SUS431. Regarding the thermal conductivity of martensitic stainless steel, SUS403 has a thermal conductivity of 25.1 W/m K, SUS410 has a thermal conductivity of 24.9 W/m K, and SUS420J1 has a thermal conductivity of 30 W/m K. , the thermal conductivity of SUS440C is 24.3 W/m·K.

On the other hand, ferritic stainless steel has a metal structure mainly composed of a ferrite phase, and SUS430 is suitable as a JIS standard. Other ferritic stainless steels include SUS405, SUS430LX, SUS430F, SUS443J1, SUS434, and SUS444. Regarding the thermal conductivity of ferritic stainless steel, the thermal conductivity of SUS430 is 26.4 W/m·K.

Furthermore, the austenitic stainless steel has a metal structure mainly composed of an austenite phase, and SUS303, SUS304, and SUS316 are suitable as JIS standards. Regarding the thermal conductivity of austenitic stainless steel, the thermal conductivity of SUS303 and SUS316 is 15 W/m·K, and the thermal conductivity of SUS304 is 16.3 W/m·K.

As described above, the thermal conductivity of stainless steel is as low as about 1/5 to 1/10 of that of aluminum.

A stack of the first plate 61 and the second plate 63 is placed on a rectangular member 68 made of an insulating material, and the rectangular member 68 is fixed on the bottom plate of the chamber 13 .

An electrostatic chuck 67 having a mounting surface on which the substrate G is directly mounted is formed on the upper surface of the first plate 61 on which the substrate G is mounted. The electrostatic chuck 67 is a dielectric film formed by spraying ceramics such as alumina, and incorporates an electrode 67a having an electrostatic adsorption function. The electrode 67a is connected to a DC power supply 75 via a power supply line 74. As shown in FIG. When the control unit 90 turns on a switch (not shown) interposed in the power supply line 74, a DC voltage is applied from the DC power supply 75 to the electrode 67a, thereby generating a Coulomb force. Due to this Coulomb force, the substrate G is electrostatically attracted to the upper surface of the electrostatic chuck 67 and held while being placed on the upper surface of the first plate 61 .

The substrate mounting table 60 is composed of a first plate 61 , a second plate 63 and an electrostatic chuck 67 . A temperature sensor such as a thermocouple (not shown) is provided on the upper surface of the electrostatic chuck 67 (the surface on which the substrate G is placed) or the first plate 61. The temperatures of the 1 plate 61 and the substrate G may be monitored at any time. A plurality of lifter pins (not shown) for transferring the substrate G are provided on the substrate mounting table 60 so as to protrude from the upper surface of the substrate mounting table 60 (the upper surface of the electrostatic chuck 67).

As shown in FIG. 2 , the first plate 61 has an outer temperature control area 61 b outside the rectangular frame-shaped gap 66 and an inner temperature control area 61 a inside the gap 66 . , the outer temperature control area 61b and the inner temperature control area 61a are continuous.

A meandering temperature control medium flow path 62a is provided in the inner temperature control area 61a so as to cover the entire area of the rectangular plane. In the illustrated example of the temperature control medium flow path 62a, for example, one end 62a1 of the temperature control medium flow path 62a is an inflow portion of the temperature control medium, and the other end 62a2 is an outflow portion of the temperature control medium.

On the other hand, the outer temperature control area 61b is provided with a temperature control medium flow path 62b in which the outward path and the return path through which the temperature control medium flows are continuous so as to cover the entire rectangular frame-shaped area. In the illustrated example of the temperature control medium flow path 62b, for example, one end 62b1 of the temperature control medium flow path 62b is an inflow portion of the temperature control medium, and the other end 62b2 is an outflow portion of the temperature control medium.

As the temperature control medium, a liquid heat medium such as a refrigerant is applied, and Galden (registered trademark), Fluorinert (registered trademark), or the like is applied to this refrigerant.

Both the temperature control medium channel 62a built in the inner temperature control area 61a and the temperature control medium channel 62b contained in the outer temperature control area 61b are examples of the "temperature control section". The temperature control section includes temperature control medium flow paths 62a and 62b through which the temperature control medium flows, as well as heaters and the like. More specifically, both the inner temperature control area 61a and the outer temperature control area 61b may have only the temperature control medium flow path as the temperature control part in the illustrated example, or may have only the heater. There is also a form having both a fluid flow path and a heater. Further, depending on the application, one may have a temperature control medium flow path and the other may have a heater. The temperature control section does not include temperature control sources such as the chillers 81 and 84 in the illustrated example, and refers only to the temperature control members incorporated in the first plate 61 that constitutes the substrate mounting table 60 . The heater, which is a resistor, is made of tungsten, molybdenum, or a compound of one of these metals and alumina, titanium, or the like.

Returning to FIG. 1, at both ends of the temperature control medium channel 62a built in the inner temperature control area 61a, a feed pipe 64a for supplying the temperature control medium to the temperature control medium channel 62a and a temperature control medium It communicates with a return pipe 64b through which the temperature control medium that flows through the flow path 62a and whose temperature is raised is discharged. A feed channel 82 and a return channel 83 communicate with the feed pipe 64 a and the return pipe 64 b respectively, and the feed channel 82 and the return channel 83 communicate with the chiller 81 . The chiller 81 has a main body that controls the temperature and discharge flow rate of the temperature control medium, and a pump that pressure-feeds the temperature control medium (both not shown).

The chiller 81, the feed channel 82 and the return channel 83 form a temperature control source 80A specific to the inner temperature control area 61a.

On the other hand, at both ends of the temperature control medium flow path 62b built in the outer temperature control area 61b, a feed pipe 64c for supplying the temperature control medium to the temperature control medium flow path 62b and the temperature control medium flow path 62b A return pipe 64d through which the temperature control medium whose temperature is raised by circulating is discharged is communicated. A feed channel 85 and a return channel 86 communicate with the feed pipe 64 c and the return pipe 64 d, respectively, and the feed channel 85 and the return channel 86 communicate with the chiller 84 . The chiller 84 has a main body that controls the temperature and discharge flow rate of the temperature control medium, and a pump that pressure-feeds the temperature control medium (both not shown).

The chiller 84, the feed channel 85 and the return channel 86 form a temperature control source 80B specific to the outer temperature control area 61b.

The substrate mounting table 60 supplies temperature control media having different temperatures to the central area corresponding to the inner temperature control area 61a and the edge area corresponding to the outer temperature control area 61b, thereby controlling each area. It is a mounting table that performs area-divided temperature control to adjust temperature to different temperatures. Therefore, the inner temperature control area 61a and the outer temperature control area 61b have unique temperature control sources 80A and 80B, respectively.

In addition, after the chiller is shared, for example, a temperature control mechanism such as a heater is provided in the feed passages 82 and 85, and after the temperature of the temperature control medium is changed by each temperature control mechanism, A configuration in which temperature control media having different temperatures are supplied to 62b may be employed. Further, when the temperature control unit includes a heater, the temperature control source includes a DC power supply (heater power supply) connected to the heater via a power supply line.

When a temperature sensor such as a thermocouple is provided on the upper surface of the electrostatic chuck 67 or the first plate 61, information monitored by the temperature sensor is transmitted to the control unit 90 as needed. Then, based on the transmitted monitor information, the controller 90 performs temperature control of (the electrostatic chuck 67 of) the substrate mounting table 60 or the first plate 61 and the substrate G. FIG. More specifically, the controller 90 adjusts the temperature and flow rate of the temperature control medium supplied from the chillers 81 and 84 to the feed passages 82 and 85 . Then, the temperature control medium whose temperature and flow rate have been adjusted is circulated through the temperature control medium flow paths 62a and 62b, so that the central area and the edge areas of the substrate mounting table 60 are temperature controlled at respective specific temperatures. can be controlled. A heat transfer gas such as He gas is supplied between the electrostatic chuck 67 and the substrate G from a heat transfer gas supply unit through a supply channel (none of which is shown). A large number of through holes (not shown) are formed in the electrostatic chuck 67, and supply channels (not shown) are embedded in the second plate 63 and the like. By supplying the heat transfer gas to the lower surface of the substrate G through the supply channel and the through hole and through the through hole of the electrostatic chuck 67, the temperature of the substrate placing table 60 whose temperature is controlled changes the heat transfer gas. The heat is quickly transferred to the substrate G via the heat, and the temperature of the substrate G is controlled.

As shown in FIG. 1, a stepped portion is formed by the outer peripheries of the electrostatic chuck 67 and the first plate 61 and the upper surface of the rectangular member 68, and a rectangular frame-shaped focus ring 69 is placed on the stepped portion. ing. The upper surface of the focus ring 69 is set to be lower than the upper surface of the electrostatic chuck 67 when the focus ring 69 is installed on the stepped portion. The focus ring 69 is made of ceramics such as alumina or quartz. The inner edge of the upper end surface of the focus ring 69 is covered with the outer peripheral edge of the substrate G while the substrate G is placed on the mounting surface of the electrostatic chuck 67 .

A through hole 63a is formed in the second plate 63, and the power supply member 70 penetrates through the through hole 63a and is connected to the lower surface of the inner temperature control area 61a. A power supply line 71 is connected to the lower end of the power supply member 70, and the power supply line 71 is connected to a high frequency power supply 73 as a bias power supply via a matching device 72 for impedance matching. That is, the inner temperature control area 61 a that constitutes the first plate 61 is electrically connected to the high frequency power supply 73 . By applying a high frequency power of, for example, 13.56 MHz from a high frequency power supply 73 to the substrate mounting table 60, ions generated by the high frequency power supply 19, which is a source for plasma generation, are attracted to the substrate G and turned into ions. Ion energy can be applied. The dependence of the etching rate on ion energy differs depending on the material forming the film to be etched. Therefore, in the plasma etching process, both the etching rate and the etching selectivity can be increased. Alternatively, the power supply member 70 may be connected to the lower surface of the second plate 63 so that high-frequency power is applied to the first plate 61 via the second plate 63 .

In this way, the first plate 61 that receives power from the high-frequency power supply 73 and performs temperature control can also be referred to as a temperature control plate. Hereinafter, the term “temperature adjustment plate” refers to the first plate 61 made of a metal with high thermal conductivity such as aluminum, which performs temperature adjustment control.

As shown in FIG. 1, the high-frequency power source 73 is connected only to the inner temperature control area 61a, and a second plate 63 made of, for example, stainless steel is connected to the lower surfaces of the inner temperature control area 61a and the outer temperature control area 61b. ing. The second plate 63 is a member that fixes the first plate 61 as a temperature control plate to the rectangular member 68 that constitutes the chamber 13 . Also, when the power supply line 71 is connected to the second plate 63 , it becomes a member that supplies high-frequency power from the high-frequency power source 73 to the temperature control plate via the conductive second plate 63 . Further, the second plate 63 is a member having a diffusion channel (not shown) for diffusing heat transfer gas such as He gas over the entire surface of the electrostatic chuck 67 . As described above, the second plate 63 is a structural member that constitutes the substrate mounting table 60, and at the same time, it is a member that requires electrical conduction performance in some cases. Hereinafter, the second plate 63 may be referred to as a "heat transfer adjusting plate".

The substrate mounting table 60 separates the center area and the edge area of the substrate mounting table 60 by circulating temperature control media having different temperatures, for example, in the inner temperature control area 61a and the outer temperature control area 61b. It is a mounting table for temperature control. For this reason, a gap 66 is provided between the inner temperature control area 61a and the outer temperature control area 61b to make it difficult to conduct heat between them. For example, the inner temperature control area 61a can be controlled to have a relatively high temperature with respect to the outer temperature control area 61b. When the first plate 61 is made of aluminum having a high thermal conductivity, the first plate 61 has a gap 66, for example, so that the entire inner temperature control area 61a can be kept at a uniform high temperature. , the entire outer temperature control area 61b can be brought into a uniform low temperature state. The inner temperature control area 61a and the outer temperature control area 61b are connected to each other above and below the gap 66 via a continuous portion, but the thickness of the continuous portion is thinner than the thickness of the first plate 61 outside the gap 66. be done. Therefore, heat transfer between the inner temperature control area 61a and the outer temperature control area 61b can be suppressed as much as possible. Accordingly, the material of the continuous portion may be aluminum, like the material other than the continuous portion, so that the gap 66 may be formed as a cavity inside the first plate 61 .

If the thermal conductivity of the second plate 63 connected to the inner temperature control area 61a and the outer temperature control area 61b is high, the temperature of the inner temperature control area 61a and the outer temperature control area 61b, which are controlled at different temperatures, will be reduced. Temperature regulation can be disturbed. Specifically, for example, heat conduction from the relatively high temperature inner temperature control area 61a to the relatively low temperature outer temperature control area 61b is promoted, and the temperature of both areas can be brought close to each other. Therefore, the substrate mounting table 60 is provided with the second plate 63 having a lower thermal conductivity than the first plate 61 . As the thermal conductivity of the second plate 63 decreases, the heat transfer action from the inner temperature control area 61a to the outer temperature control area 61b decreases. It is preferably formed from the lowest austenitic stainless steel.

The thickness of the first plate 61 can be set within a range of 25 mm to 50 mm, for example. Since the inner temperature control area 61a and the outer temperature control area 61b, which constitute the first plate 61, have temperature control medium flow paths 62a and 62b therein, respectively, a certain thickness is required. On the other hand, the thickness of the first plate 61 is preferably as thin as possible from the viewpoint of making it easier to create a temperature difference between the inner temperature control area 61a and the outer temperature control area 61b. More specifically, the temperature control medium flow paths 62a and 62b are arranged in the first plate 61 so that the thickness of the upper and lower gaps 66 between the temperature control medium flow paths 62a and 62b in the first plate 61 is as thin as possible. is provided, it is possible to easily create a temperature difference between the inner temperature control area 61a and the outer temperature control area 61b.

On the other hand, the thickness of the second plate 63 can be set within a range of 20 mm to 45 mm, for example. It is desired that the thickness of the second plate 63 be reduced in order to reduce the heat transfer effect. However, since it has the same planar dimension as the substrate G for FPD, if the thickness of the second plate 63 is less than 20 mm, a strength problem due to lack of rigidity such as deformation due to bending occurs. It is preferable to set the thickness of the second plate 63 to 20 mm or more. On the other hand, the thickness of the second plate 63 is preferably set to 45 mm or less from the viewpoint of heat transfer and that stainless steel, which is highly versatile as a material for the substrate mounting table, has a thickness of about 45 mm (material cost).

The control unit 90 controls each component of the substrate processing apparatus 100, for example, the chillers 81 and 84 constituting the temperature control sources 80A and 80B, the high-frequency power sources 19 and 73, the processing gas supply unit 40, and the monitor transmitted from the pressure gauge. The operation of the gas exhaust unit 50 and the like is controlled based on the information. The control unit 90 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU executes a predetermined process according to a recipe (process recipe) stored in a storage area such as RAM. Control information for the substrate processing apparatus 100 with respect to process conditions is set in the recipe. The control information includes, for example, the gas flow rate, the pressure inside the processing container 10, the temperature inside the processing container 10, the temperatures of the inner temperature control area 61a and the outer temperature control area 61b that constitute the first plate 61, the process time, and the like. be For example, the recipe includes processing for controlling the temperature of each of the inner temperature control area 61a and the outer temperature control area 61b to a specific temperature suitable for plasma etching processing or the like. Here, the “specific temperature suitable for plasma etching processing etc.” means that the etching rate of the insulating film, electrode film, etc. in the entire range of the wide substrate G for FPD is the same, and the in-plane uniformity is high. is the specific temperature for each area in which it is suitable for

The recipe and the program applied by the control unit 90 may be stored in, for example, a hard disk, a compact disk, a magneto-optical disk, or the like. Also, the recipe and the like may be stored in a portable computer-readable storage medium such as a CD-ROM, DVD, memory card, etc., and set in the control unit 90 to be read out. The control unit 90 also has a user interface such as an input device such as a keyboard and a mouse for inputting commands, a display device such as a display for visualizing and displaying the operating status of the substrate processing apparatus 100, and an output device such as a printer. have.

According to the substrate processing method using the substrate processing apparatus 100, by performing temperature control unique to each area, processing with high in-plane uniformity can be realized in the wide substrate G for FPD. . Furthermore, as will be described in detail below, since the substrate G is placed on a temperature adjustment plate (first plate 61) with high thermal conductivity, which performs temperature adjustment control, good thermal responsiveness (or temperature responsiveness) can be performed. Therefore, it is possible to stabilize the temperature of the temperature adjustment plate at a stage where the number of substrates G to be processed (in other words, the number of times the plasma is turned on and off) is small.

(Modified example of the first plate)
Next, a modification of the first plate having multiple temperature control areas will be described with reference to FIG. 3A to 3E are plan views simulating modified examples of the first plate.

The first plate 61A shown in FIG. 3A is a rectangular metal plate in plan view divided into three areas by two rectangular frame-shaped gaps 66 from the center toward the outer circumference. It has an outer area 61e. The inner area 61c, the intermediate area 61d, and the outer area 61e incorporate temperature control units such as temperature control medium flow paths and heaters, respectively. not shown). For example, temperature control is performed for three areas so that the temperature decreases in the order of the inner area 61c, the intermediate area 61d, and the outer area 61e.

On the other hand, the first plate 61B shown in FIG. 3B has four corners of a rectangular metal plate in plan view divided into five areas by L-shaped or reversed L-shaped gaps 66, with a central area 61f and four corners. It has a corner area 61g. For example, two areas are temperature-controlled such that the center area 61f has a higher temperature than the corner area 61g.

On the other hand, the first plate 61C shown in FIG. 3C is divided into five areas by U-shaped or inverted U-shaped gaps 66 at the central positions of four edges of a rectangular metal plate in plan view, It has a center area 61h and four edge center areas 61j. For example, two areas are temperature-controlled such that the center area 61h has a higher temperature than the edge center area 61j.

On the other hand, the first plate 61D shown in FIG. 3D is a rectangular metal plate in plan view divided into nine areas by grid-like gaps 66, and has a central area 61k, corner areas 61m, and side central areas 61n. The center area 61k, the corner area 61m, and the side center area 61n incorporate temperature control units such as temperature control medium flow paths and heaters, respectively, and each temperature control unit has a unique temperature control source (all not shown). For example, temperature control is performed for three areas so that the temperature decreases in the order of the center area 61k, the corner area 61m, and the side center area 61n. Note that the side center area 61n may be subjected to temperature control control that differs between the side center area on the long side and the side center area on the short side.

Further, the first plate 61E shown in FIG. 3E is a rectangular metal plate in plan view and is divided into three large areas by two rectangular frame-shaped gaps 66 from the center toward the outer circumference. Specifically, it has an inner area 61p and a middle area 61q, and furthermore, the outer area consists of four corner areas 61r and four edge center areas 61s and 61t separated by gaps 66. It is a divided form. Of the four edges, two long sides may have an edge central area 61s, and two short sides may have an edge central area 61t. The inner area 61p, the intermediate area 61q, the corner area 61r, and the edge center areas 61s and 61t each incorporate a temperature control section such as a unique temperature control medium flow path and a heater, and each temperature control section has a unique temperature. source (neither shown).

In this first plate 61E, there are multiple forms of temperature control for each area. The first temperature control form in the first plate 61E is, for example, temperature control of four areas so that the temperature decreases in the order of the inner area 61p, the intermediate area 61q, the corner area 61r, and the edge central areas 61s and 61t. done. Here, the edge center areas 61s and 61t are controlled to the same temperature.

On the other hand, in the second temperature control mode in the first plate 61E, for example, the inner area 61p, the intermediate area 61q, the corner area 61r, the edge central area 61s, and the edge central area 61t are lowered in order of temperature. Area temperature control is performed. Here, the edge center areas 61s and 61t are controlled to different temperatures.

In the first plate according to any of the modified examples, the unique temperature control is performed for each area, so that the wide substrate G for FPD can be processed with high in-plane uniformity.

[Temperature analysis]
Next, with reference to FIG. 4 and Table 1, the results of temperature analysis will be described. In this temperature analysis, the metal types of the temperature control plate having the temperature control medium flow path and the heat transfer control plate connected to the temperature control plate are changed, and the vertical positions of the temperature control plate and the heat transfer control plate are changed. Four types of analysis models were created by inverting the model, and temperature analysis was performed for each analysis model. Through this temperature analysis, the temperatures at multiple locations on the temperature control plate were specified, and the temperature difference between the maximum temperature and the minimum temperature was verified. Here, both FIGS. 4A and 4B are side views of an example of a substrate mounting table model used in temperature analysis, and FIG. 4C is a CC arrow view of FIGS. 4A and 4B, FIG. 4 is a cross-sectional view of the temperature adjustment plate model, showing an analysis temperature specific location;

(Analysis overview)
The present inventors created the following four types of analysis models in the computer. Analysis models 1 to 3 below are comparative examples 1 to 3, respectively, and analysis model 4 is an example. For the sake of convenience, the model having the temperature control medium channel is referred to as the temperature control plate model, and the model not having the temperature control medium channel is referred to as the heat transfer control plate model, regardless of whether they are arranged vertically.

<Analysis model 1>
The analysis model 1 is the analysis model M1 shown in FIG. 4A, and has a temperature adjustment plate model Mb at the bottom and a heat transfer adjustment plate model Ma at the top. The temperature adjustment plate model Mb is made of A5052 and has a thickness of 45 mm. The heat transfer adjustment plate model Ma is made of SUS304 and has a thickness of 25 mm. As shown in FIG. 4C, the temperature control plate model Mb has an inner temperature control area Mb1 and an outer temperature control area Mb2 with a rectangular frame-shaped gap G therebetween. The inner temperature control area Mb1 has a temperature control medium flow path model Mb11, and the outer temperature control area Mb2 has a temperature control medium flow path model Mb21.

<Analysis model 2>
Although the basic configuration is the same as that of the analysis model 1, both the temperature adjustment plate model Mb and the heat transfer adjustment plate model Ma are made of A5052.

<Analysis model 3>
The analysis model 3 is the analysis model M2 shown in FIG. 4B, and has a temperature adjustment plate model Mc on the upper side and a heat transfer adjustment plate model Md on the lower side. The temperature adjustment plate model Mc is made of A5052 and has a thickness of 25 mm, and the heat transfer adjustment plate model Md is made of A5052 and has a thickness of 25 mm. As shown in FIG. 4C, the temperature control plate model Mc has an inner temperature control area Mc1 and an outer temperature control area Mc2 with a rectangular frame-shaped gap G therebetween. The inner temperature control area Mc1 has a temperature control medium flow path model Mc11, and the outer temperature control area Mc2 has a temperature control medium flow path model Mc21.

<Analysis model 4>
Although the basic configuration is the same as that of the analysis model 3, the material of the temperature adjustment plate model Mc is A5052, and the material of the heat transfer adjustment plate model Md is SUS304.

In this temperature analysis, a temperature control medium of 50° C. was circulated through the temperature control medium flow path models Mb11 and Mc11, and a temperature control medium of 0° C. was circulated through the temperature control medium flow path models Mb21 and Mc21.

(Analysis result)
Points O to C indicate a plurality of analysis temperature specific points in FIG. 4C. Here, the point O is the center point of the analytical models M1 and M2, the point A is the center position of the short side, the point C is the corner position, and the point B is on the straight line connecting the points O and C. is a position corresponding to the gap G in . In each analysis model, the point O indicates the highest temperature and the point C indicates the lowest temperature, and the difference value between them was obtained. The results are shown in Table 1 below.

From Table 1, it was found that the two cases of Comparative Example 1 and Example, which had the largest difference value between the maximum temperature and the minimum temperature, were preferable area temperature control modes.

Then, next, verification regarding thermal responsiveness is performed below.

[A study on thermal responsiveness]
One consideration regarding thermal responsiveness will be described with reference to FIG. Here, FIG. 5A is a graph showing a correlation graph between the number of times of discharge and electrode temperature in Example and Comparative Example 1 in the above temperature analysis, and FIG. 5B is an enlarged view of part B of FIG. 5A.

Thermal responsiveness (or temperature responsiveness) refers to the temperature stability of the electrode plate in the process of repeating the plasma treatment after adjusting the temperature of the electrode plate. The shorter (smaller) the better the thermal responsiveness.

As the number of processed substrates increases, in other words, the number of plasma ON-OFF repetitions (the number of discharges) causes the temperature of the temperature control plate to rise gradually. Since the temperature control plate of the example is made of aluminum, which has high thermal conductivity, plasma processing can be performed with good thermal responsiveness. Therefore, as shown in FIG. 5A, the temperature of the temperature adjustment plate can be stabilized at a stage where the number of discharges is small, and a process that does not depend on the number of substrates G to be processed can be realized.

On the other hand, the heat transfer adjusting plate of Comparative Example 1 is made of stainless steel with low thermal conductivity. The time required for the temperature of the heat adjustment plate to stabilize is longer than in the example. Incidentally, as shown in FIG. 5B, the plasma is turned on at the position X1 and turned off at the position X2. By repeating such discharge, the temperature stabilizes. As compared with the example, the number of times of discharge until the temperature is stabilized may be less.

In this way, considering both the results of the temperature analysis described above and the consideration of thermal responsiveness, it can be concluded that the configuration of the temperature control plate and the heat transfer control plate of the example is preferable.

[Experiment on temperature dependence of etching rate and selectivity]
Next, experiments on the temperature dependence of the etching rate and selectivity of a plurality of insulating films will be described with reference to FIGS. 6 to 10. FIG. Here, FIG. 6 is a diagram simulating a plan view of the substrate mounting table applied in the experiment.

(Outline of the experiment)
In this experiment, the temperature of the mounting table was changed to evaluate the process performance in each area. In the experiment, the central rectangular area in plan view corresponding to the inner temperature control area was defined as the center area CA including the center point O, and the outer rectangular frame-shaped area in plan view corresponding to the outer temperature control area was defined as the edge area including the edge E. Let EA. Further, the intermediate line between the center area CA and the edge area EA is defined as a middle area MA.

In this experiment, the substrate processing apparatus in which the substrate mounting table is accommodated is an inductively coupled plasma processing apparatus, the pressure inside the chamber is set to 5 mTorr to 15 mTorr (0.665 Pa to 1.995 Pa), and the ICP source power and bias Both powers were set between 5 kW and 15 kW. Etching gases include F-based gases such as CHF ₃ , CH ₂ F ₂ , CH ₃ F, CF ₄ , C ₄ F ₈ and C ₅ F ₈ , and diluent gases such as He and Ar. , and a gas selected from Xe, etc., to perform plasma etching.

In this experiment, a test sample with a SiN film formed on the substrate, a test sample with a SiO film formed on the substrate, and a Si film (poly-Si film) for the gate electrode formed on the substrate were used. The temperature dependence of the etching rate of each insulating film and electrode film was verified for the test specimens. Furthermore, the temperature dependence of the SiO/Si selectivity (selectivity of the SiO film) was also verified in a multilayer film in which a Si film and a SiO film are formed on a substrate.

(Experimental result)
FIG. 7 is a graph showing experimental results regarding the temperature dependence of the etching rate of the SiN film. Further, FIG. 8 is a graph showing experimental results regarding the temperature dependence of the etching rate of the SiO film. Further, FIG. 9 is a graph showing experimental results regarding the temperature dependence of the etching rate of the Si film. Further, FIG. 10 is a graph showing experimental results regarding the temperature dependence of the SiO/Si selectivity.

In each graph, the solid line graph is a graph regarding the temperature dependence of the etching rate and selectivity in the edge area of the substrate mounting table shown in FIG. 6, and the dotted line graph is the temperature dependence of the etching rate and selectivity in the center area shown in FIG. It is a graph about sex. Further, the dashed-dotted line is a graph regarding the temperature dependence of the etching rate and selectivity in the middle area shown in FIG.

FIG. 7 proves that the SiN film has temperature dependence. Regarding the etching rate of the edge area, it can be seen that there is no large difference in the etching rate between the low temperature and the high temperature. On the other hand, it can be seen that the etching rate in the center area is low at low temperatures and high at high temperatures, and is approximately the same as the etching rate at low temperatures in the edge areas.

From the experimental results shown in FIG. 7, in the etching process of the SiN film, the edge area of the substrate mounting table is controlled to a low temperature and the center area is controlled to a high temperature. It has been demonstrated that a high etching rate that is as uniform as possible can be obtained over the entire surface.

Next, FIG. 8 proves that the SiO film has no temperature dependence. Therefore, it can be seen that the area-by-area temperature control is not always necessary when etching the SiO film.

Next, FIG. 9 demonstrates that the Si film has temperature dependence. Regarding the etching rate of the edge area, there is a certain difference in the etching rate between the low temperature and the high temperature. I understand.

From the experimental results shown in FIG. 9, with respect to the etching process of the Si film, the edge area of the substrate mounting table is controlled to a low temperature and the center area is controlled to a high temperature. It has been demonstrated that an etch rate that is as uniform as possible can be obtained throughout. By comparing FIGS. 7 and 8 with FIG. 9, it can be seen that the etching rate of the Si film is lower than the etching rate of insulating films such as SiN films and SiO films. This leads to an increase in the SiO/Si selection ratio shown in FIG.

FIG. 10 demonstrates that the SiO/Si selection ratio has temperature dependence. As for the selectivity of the edge area, it can be seen that it is high at low temperatures and decreases sharply as the temperature rises, showing a tendency opposite to the edge graphs shown in FIGS. On the other hand, it can be seen that the selectivity of the center area is high at low temperatures (higher than that of the edge graph) and gradually decreases as the temperature rises, but is about the same as the selectivity of the edge graph at low temperatures.

From the experimental results shown in FIG. 10, in the etching process of the SiO film formed on the Si film, by adjusting the temperature of the edge area of the substrate mounting table to a low temperature and adjusting the temperature of the center area to a high temperature, the substrate It has been demonstrated that a high SiO selectivity that is as uniform as possible over the entire area of the support table is obtained.

In this experiment, in both the etching process of the SiN film and the etching process of the Si film, the temperature of the edge area of the substrate mounting table was adjusted to a low temperature, and the temperature of the center area was adjusted to a high temperature. The etching process can be performed as uniformly as possible over the range. In particular, in the case of a SiN film, a high etching rate can be obtained in addition to performing a uniform etching process as much as possible over the entire range of the substrate. Also, in the etching process of the SiO film formed on the Si film, the temperature of the edge area of the substrate mounting table is adjusted to a low temperature, and the temperature of the center area is adjusted to a high temperature. A uniform and high SiO/Si selectivity can be obtained over the entire surface.

In addition, depending on the types of insulating films such as SiN films and SiO films and conductive films such as Si films, the suitable temperature control temperature for each of the edge area and the center area may differ. Accordingly, it is desirable to perform temperature control for each area at a suitable temperature control temperature for each area.

Other embodiments may be possible in which other components are combined with the configurations and the like described in the above embodiments, and the present disclosure is not limited to the configurations shown here. This point can be changed without departing from the gist of the present disclosure, and can be determined appropriately according to the application form.

For example, the illustrated substrate processing apparatus 100 has been described as an inductively coupled plasma processing apparatus having a dielectric window, but an inductively coupled plasma processing apparatus having a metal window instead of the dielectric window may be used. Alternatively, it may be another type of plasma processing apparatus. Specific examples include electron cyclotron resonance plasma (ECP), helicon wave excited plasma (HWP), and parallel plate plasma (capacitively coupled plasma; CCP). Also, a microwave-excited surface wave plasma (SWP) is exemplified. All of these plasma processing apparatuses, including ICP, can independently control the ion flux and ion energy, can freely control the etching shape and selectivity, and have a high electron density of about 10 ¹¹ to 10 ¹³ cm ⁻³ . is obtained.

Further, the substrate processing apparatus 100 has a high-frequency electrode by a high-frequency power source 19 connected to the high-frequency antenna 15 on the opposite surface of the substrate G, and a high-frequency electrode by a high-frequency power source 73 connected to the first plate 61 on the substrate mounting table 60 . Although the apparatus has electrodes, it may be a substrate processing apparatus having only one of the high-frequency electrodes.

Further, when each temperature control area constituting the first plate 61 of the substrate processing apparatus 100 has a built-in heater as a temperature control part and film formation is performed using a thermal CVD method, generation of plasma is not necessarily required. .

Further, a substrate mounting table that does not have the electrostatic chuck 67 on the upper surface of the first plate 61 and the focus ring 69 on the upper surface of the rectangular member 68 may be applied.

10 Processing Container 60 Substrate Mounting Table 61 First Plate (Temperature Adjustment Plate)
61a temperature control area (inner temperature control area)
61b temperature control area (outside temperature control area)
62a, 62b temperature control medium flow path (temperature control part)
63 Second plate (heat transfer adjustment plate)
66 Gap 80A, 80B Temperature control source 100 Substrate processing apparatus G Substrate

Claims (14)

A substrate mounting table on which the substrate is mounted and the temperature of which is controlled when the substrate is processed in the processing container,
a metal first plate that is divided into a plurality of temperature control areas via gaps;
a second metal plate in contact with the first plate and having a lower thermal conductivity than the first plate;
Each of the temperature control areas incorporates a temperature control unit that performs unique temperature control,
the first plate having an upper surface for mounting the substrate is mounted on the upper surface of the second plate ;
The plurality of temperature control areas are continuous above and below the gap,
The first plate has a rectangular outer shape in plan view, and the corners are divided into areas by the gaps of L-shape or inverted L-shape, or the central position of the edge side is U-shaped or inverted U-shaped. A substrate mounting table including a configuration divided into areas by the U-shaped gap . The first plate is made of aluminum or an aluminum alloy,
2. The substrate mounting table according to claim 1, wherein said second plate is made of stainless steel. 3. The substrate mounting table according to claim 2, wherein said second plate is made of austenitic stainless steel. 4. The substrate mounting table according to claim 1 , wherein a power supply is electrically connected to any one of said temperature control areas. The substrate mounting table according to any one of claims 1 to 4 , wherein the temperature control section has at least one of a heater and a temperature control medium flow path through which a temperature control medium flows. A substrate processing apparatus comprising a processing container, a substrate mounting table for placing a substrate in the processing container and controlling the temperature thereof, and a temperature control source for the substrate mounting table,
The substrate mounting table is
a metal first plate that is divided into a plurality of temperature control areas via gaps;
a second metal plate in contact with the first plate and having a lower thermal conductivity than the first plate;
Each of the temperature control areas incorporates a temperature control unit that performs unique temperature control,
the first plate having an upper surface for mounting the substrate is mounted on the upper surface of the second plate ;
The plurality of temperature control areas are continuous above and below the gap,
The first plate has a rectangular outer shape in plan view, and the corners are divided into areas by the gaps of L-shape or inverted L-shape, or the central position of the edge side is U-shaped or inverted U-shaped. A substrate processing apparatus including a configuration in which areas are divided by the U-shaped gap . The first plate is made of aluminum or an aluminum alloy,
7. The substrate processing apparatus of claim 6 , wherein said second plate is made of stainless steel. 8. The substrate processing apparatus according to claim 7 , wherein said second plate is made of austenitic stainless steel. 9. The substrate processing apparatus according to claim 6 , wherein said plurality of temperature control areas are continuous above and below said gap. 10. The substrate processing apparatus according to claim 6 , wherein a power supply is electrically connected to any one of said temperature control areas. The temperature control unit has at least one of a heater and a temperature control medium flow path through which a temperature control medium flows,
11. The substrate processing apparatus according to claim 6 , wherein said temperature control source corresponding to said heater is a heater power supply, and said temperature control source corresponding to said temperature control medium flow path is a chiller. The substrate processing apparatus further has a control unit,
12. The control unit according to any one of claims 6 to 11 , wherein the control unit causes the temperature control source to perform temperature control at a temperature unique to the temperature control unit of each of the temperature control areas. A substrate processing apparatus as described. The substrate mounting table has a rectangular outer shape in a plan view,
The temperature control area has an outer temperature control area in the shape of a rectangular frame, and an inner temperature control area that is rectangular in plan view and disposed inside the outer temperature control area with the gap therebetween,
Both the outer temperature control area and the inner temperature control area incorporate a temperature control medium flow path,
The controller controls the temperature control source to transfer a temperature control medium having a temperature relatively higher than that of the temperature control medium flowing through the temperature control medium flow path of the outer temperature control area to the temperature control medium of the inner temperature control area. 13. The substrate processing apparatus according to claim 12 , which executes control to circulate through the preparation medium flow path. A substrate processing method using a substrate processing apparatus having a processing container, a substrate mounting table on which a substrate is mounted and temperature-controlled in the processing container, and a temperature control source for the substrate mounting table,
The substrate mounting table is
a metal first plate that is divided into a plurality of temperature control areas via gaps;
a second metal plate in contact with the first plate and having a lower thermal conductivity than the first plate;
Each of the temperature control areas incorporates a temperature control unit that performs unique temperature control,
the first plate having an upper surface for mounting the substrate is mounted on the upper surface of the second plate;
The plurality of temperature control areas are continuous above and below the gap,
The first plate has a rectangular outer shape in plan view, and the corners are divided into areas by the gaps of L-shape or inverted L-shape, or the central position of the edge side is U-shaped or inverted U-shaped. including a configuration divided into areas by the square-shaped gap,
A substrate processing method, wherein substrate processing is performed while performing unique temperature control in each of the temperature control areas.

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