CN107086200A - Substrate-placing platform and substrate board treatment - Google Patents

Abstract

The present invention provides a substrate mounting table having an electrostatic chuck, which is less prone to cracking and peeling off of a dielectric layer formed of a ceramic sprayed coating of the electrostatic chuck even at a temperature exceeding 120°C. A substrate mounting table (30) for mounting a substrate in a substrate processing apparatus for processing a substrate to be processed in a processing container (4) and used at a temperature exceeding 120°C includes: a metal base (31); An electrostatic chuck (32) that adsorbs the substrate to be processed has a dielectric layer (45) formed on a substrate (31) and a dielectric layer (45) formed by ceramic spray coating and an adsorption electrode ( 46), wherein at least the part of the substrate (31) in contact with the dielectric layer (45) is made of martensitic stainless steel or ferritic stainless steel.

Description

Substrate mounting table and substrate processing device

technical field

The present invention relates to a substrate mounting table for mounting a substrate and a substrate processing apparatus using the same.

Background technique

In the manufacturing process of a flat panel display (FPD), etching, sputtering, CVD (Chemical Vapor Deposition), and the like are performed on the substrate to be processed.

As a substrate processing apparatus that performs such processing, a substrate to be processed is mounted on a substrate mounting table arranged in a chamber (processing container), and plasma is generated in the chamber while the inside of the processing container is kept in a vacuum state. A device for performing plasma treatment on a substrate to be processed.

As a substrate mounting table of such a substrate processing apparatus, a substrate mounting table having a base and an electrostatic chuck provided thereon is known. The electrostatic chuck includes a dielectric layer formed by ceramic spray coating and an adsorption electrode disposed therein. By applying a DC voltage to the adsorption electrode, an electrostatic adsorption force such as Coulomb force and Johnson-Rahbeck force is used to hold the object. Process the substrate for adsorption fixation.

Conventionally, aluminum is often used as the substrate and alumina is often used as the dielectric layer. However, the linear expansion coefficient of aluminum is 23.8×10 ^-6 /°C, while the linear expansion coefficient of aluminum oxide is 6.4×10 ^-6 /°C. When the temperature of the substrate mounting table rises due to heat such as plasma, a large pressure is applied to the dielectric layer, and cracks and peeling may occur in the dielectric layer. In particular, such a problem becomes conspicuous on a mounting table for a large-sized FPD substrate.

Therefore, it has been proposed to form a dielectric layer with a ceramic sprayed coating having a linear expansion coefficient of 14×10 ^-6 /°C or less in absolute value of the difference in the linear expansion coefficient with the substrate, and to prevent such cracks in the dielectric layer (patent Literature 1).

prior art literature

patent documents

Patent Document 1: Patent No. 4994121

Contents of the invention

The problem to be solved by the invention

However, there are high-temperature processes such as film-forming processes as processes for FPD substrates, but when the temperature exceeds 120°C on a substrate mounting table with an electrostatic chuck, only the dielectric layer and the substrate of the electrostatic chuck are adjusted based on the technology of Patent Document 1. In the case of poor thermal expansion, the ceramic sprayed coating constituting the dielectric layer cannot follow the expansion of the substrate, and it is difficult to effectively prevent cracking and peeling of the dielectric layer.

On the other hand, in a film formation apparatus that performs chemical vapor deposition (CVD) as a high-temperature process, there are cases where a substrate mounting table without a structure using an electrostatic chuck is used. A gap occurs between the surfaces, making it difficult to control the temperature of the substrate with high precision. In addition, a mechanism for mechanically clamping the substrate may be used, but since only the outer periphery of the substrate is clamped, a gap remains in the center of the substrate, and it is still difficult to control the temperature of the substrate.

Therefore, the object of the present invention is to provide a substrate mounting table with an electrostatic chuck and a substrate processing apparatus using the same, even at a temperature exceeding 120° C., the dielectric layer formed of a ceramic sprayed coating on the electrostatic chuck is difficult to Cracks and peeling occur.

means to solve the problem

In order to solve the above-mentioned problems, a first aspect of the present invention provides a substrate mounting table for mounting a substrate in a substrate processing apparatus that processes a substrate to be processed in a processing container, and is used at a temperature exceeding 120° C. The substrate mounting table is characterized in that it includes: a base made of metal; and an electrostatic chuck that absorbs the substrate to be processed, and has a dielectric layer formed of a ceramic sprayed coating disposed on the base and a dielectric layer disposed on the dielectric layer. As for the inner adsorption electrode, at least a portion of the substrate in contact with the dielectric layer is made of martensitic stainless steel or ferritic stainless steel.

In the above-mentioned first viewpoint, the substrate mounting table further includes a temperature adjustment mechanism for adjusting the temperature of the substrate to be processed on the electrostatic chuck to a predetermined temperature via the base body and the electrostatic chuck, and the substrate mounting table can be adjusted by the temperature adjustment mechanism. It becomes the temperature exceeding 120 degreeC. In this case, the above-mentioned base body can adopt the following configuration, that is, including: an upper plate in contact with the above-mentioned dielectric layer of the above-mentioned electrostatic chuck; To adjust the temperature, at least the upper plate is made of martensitic stainless steel or ferritic stainless steel.

A second aspect of the present invention provides a substrate mounting table for mounting a substrate in a substrate processing apparatus that processes a substrate to be processed in a processing container, and is used at a temperature exceeding 120° C., the characteristics of the substrate mounting table Including: a base made of metal; and an electrostatic chuck for adsorbing a substrate to be processed, which has a dielectric layer formed of a ceramic sprayed coating disposed on the base and an adsorption electrode disposed inside the dielectric layer, When the Young's modulus of the above-mentioned ceramic sprayed coating constituting the above-mentioned dielectric layer is E, the linear expansion coefficient difference between the portion of the above-mentioned base body at least in contact with the above-mentioned dielectric layer and the above-mentioned ceramic sprayed coating constituting the above-mentioned dielectric layer is In the case of Δα, E×Δα≦2×10 ⁶ [(N/m ² )/°C] is satisfied.

In the second viewpoint, the substrate mounting table further includes a temperature adjustment mechanism for adjusting the temperature of the substrate to be processed on the electrostatic chuck to a predetermined temperature via the base body and the electrostatic chuck, and the substrate mounting table can be adjusted by the temperature adjustment mechanism. It becomes the temperature exceeding 120 degreeC. In this case, the base body includes: an upper plate in contact with the dielectric layer of the electrostatic chuck; When the linear expansion coefficient difference of the ceramic sprayed coating of the dielectric layer is Δα, E×Δα≦2×10 ⁶ [(N/m ² )/°C] is satisfied.

In the above-mentioned first and second viewpoints, the ceramic sprayed coating constituting the above-mentioned dielectric layer can be selected from _Al2O3 (alumina), MgO· _SiO2 (talc), 2MgO· _{SiO2 (} forsterite) , at least one of YF ₃ and Y ₂ O ₃ (yttrium oxide). In addition, the ceramic sprayed coating constituting the dielectric layer is preferably selected from MgO·SiO ₂ (talc), 2MgO·SiO ₂ (forsterite), YF ₃ and Y ₂ O ₃ (yttrium oxide). In addition, the ceramic sprayed coating constituting the above-mentioned dielectric layer may be a mixture of Y ₂ O ₃ ·Al ₂ O ₃ ·SiO ₂ and Y ₂ O ₃ At least one composition of Al ₂ O ₃ .SiO ₂ .Si ₃ N ₄ . In addition, the ceramic sprayed coating constituting the above-mentioned dielectric layer can be made of Al ₂ O ₃ (aluminum oxide), MgO·SiO ₂ (talc), 2MgO·SiO ₂ (forsterite), YF ₃ and Y ₂ O ₃ At least one of (yttrium oxide) and Y ₂ O ₃ .Al ₂ O ₃ .SiO ₂ and Y ₂ O ₃ .Al ₂ O ₃ as a mixture obtained by arbitrarily changing the proportion of the powder to be sprayed • At least one composition of SiO ₂ •Si ₃ N ₄ .

A third viewpoint of the present invention provides a substrate processing apparatus, characterized by comprising: a processing container for processing a substrate to be processed; The substrate mounting table described in ; the processing gas supply mechanism for supplying processing gas to the above-mentioned processing container; the processing gas introduction part that introduces the above-mentioned processing gas supplied from the above-mentioned processing gas supply mechanism into the above-mentioned processing container; and the above-mentioned processing container Exhaust mechanism for internal exhaust.

Invention effect

According to the present invention, martensitic stainless steel or ferritic stainless steel is used as the substrate, or the Young's modulus of the ceramic sprayed coating constituting the dielectric layer is E, at least the part of the substrate in contact with the dielectric layer and the When the linear expansion coefficient difference of the above-mentioned ceramic sprayed coating is Δα, E×Δα≤2×10 ⁶ [(N/m ² )/°C] is satisfied, and thus, even at a temperature exceeding 120°C, It is also possible to prevent cracks and peeling from occurring in the dielectric layer formed of the ceramic sprayed coating of the electrostatic chuck.

Description of drawings

1 is a cross-sectional view showing a plasma processing apparatus as a substrate processing apparatus using a substrate mounting table according to an embodiment of the present invention.

Fig. 2 is a substrate mounting table (structure A) with a structure combining an aluminum substrate and an Al ₂ O ₃ spray coating, and a substrate mounting table with a structure combining an austenitic stainless steel base and an Al ₂ O ₃ spray coating (Structure B), a substrate mounting table with a structure combining a martensitic stainless steel substrate and an Al ₂ O ₃ spray coating (structure C), showing the relationship between the linear expansion coefficient difference Δα and the heat-resistant temperature and Δα and E×Δα diagram of the relationship.

3 is a cross-sectional view showing a substrate mounting table according to another embodiment of the present invention.

Explanation of reference signs

1: main container

2: Dielectric wall

3: Antenna container

4: chamber

5: Metal support frame

11: Spray frame

13: High frequency antenna

14: Matcher

15: High frequency power supply

16: Power supply components

17: spacer

19: Power supply line

20: Process gas supply system

22: terminal

30: Substrate mounting table

31: matrix

32: Electrostatic Chuck

33: Side wall insulating part

35: Upper plate

36: Lower board

37: Temperature regulating medium flow path

38: Heater

39: Temperature regulating medium flow pipe

40: Temperature regulating medium supply part

41: heater power supply

45: Dielectric layer (ceramic spray coating)

46: adsorption electrode

47: Power supply line

48: DC power supply

52: exhaust device

60: Control Department

73: High frequency power supply

100: Plasma treatment device

G: Substrate.

detailed description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, in all the drawings, common reference numerals are assigned to common parts.

1 is a cross-sectional view showing a plasma processing apparatus as a substrate processing apparatus using a substrate mounting table according to an embodiment of the present invention.

As shown in FIG. 1 , this plasma processing apparatus is configured as an inductively coupled plasma etching apparatus for etching a rectangular glass substrate (hereinafter referred to simply as “substrate”) G for FPD. Examples of the FPD include a liquid crystal display (LCD), an electroluminescence (Electro Luminescence; EL) display, a plasma display panel (PDP), and the like.

This plasma processing apparatus 100 has an airtight main body container 1 in the shape of an angular cylinder formed of a conductive material such as aluminum whose inner wall surface has been anodized. The main body container 1 is detachably assembled and grounded by a grounding wire 1a. The main body container 1 is divided into upper and lower parts by a dielectric wall 2, the upper side is an antenna container 3 forming an antenna chamber, and the lower side is a chamber (processing container) 4 forming a processing chamber. The dielectric wall 2 forms the top wall of the chamber 4 . The dielectric wall 2 is made of ceramics such as Al ₂ O ₃ , quartz, or the like.

A support frame 5 protruding inward is provided between the side wall 3 a of the antenna container 3 and the side wall 4 a of the chamber 4 in the main body container 1 , and the dielectric wall 2 is placed on the support frame 5 .

A shower frame 11 for supplying process gas is fitted in a lower portion of the dielectric wall 2 . The shower frame 11 is provided in a cross shape, and is a structure supporting the dielectric wall 2 from below, for example, a beam structure. Here, the shower frame 11 supporting the above-mentioned dielectric wall 2 is in a state of being suspended from the top of the main body container 1 by a plurality of suspenders (not shown). The metal support frame 5 and the shower frame 11 can be covered by dielectric components.

The shower frame 11 is made of a conductive material, preferably metal, for example, aluminum whose inner surface or outer surface is anodized so as not to generate pollutants. A gas flow path 12 extending horizontally is formed in the shower frame 11, and the gas flow path 12 communicates with a plurality of gas discharge holes 12a extending downward. On the other hand, a gas supply pipe 20 a is provided at the center of the upper surface of the dielectric wall 2 so as to communicate with the gas flow path 12 . The gas supply pipe 20a penetrates from the top of the main body container 1 to the outside thereof, and is connected to a processing gas supply system 20 including a processing gas supply source, a valve system, and the like. Therefore, in the plasma processing, the processing gas supplied from the processing gas supply system 20 is supplied into the shower housing 11 through the gas supply pipe 20a, and is discharged into the chamber 4 through the gas discharge hole 12a on the lower surface thereof.

A radio frequency (RF) antenna 13 is arranged inside the antenna case 3 . The high-frequency antenna 13 is configured by arranging an antenna wire 13 a made of a metal with high conductivity such as copper and aluminum in any conventionally used shape such as a loop or a spiral. A multiple antenna having a plurality of antenna units may also be used.

The terminal 22 of the antenna wire 13 a is connected to the power feeding member 16 extending above the antenna case 3 . The upper end of the power supply unit 16 is connected to the high-frequency power supply 15 through a power supply line 19 . In addition, a matching unit 14 is attached to the power supply line 19 . Further, the high-frequency antenna 13 is separated from the dielectric wall 2 by a spacer 17 formed of an insulating member. Further, by supplying high-frequency power with a frequency of 13.56 MHz from the high-frequency power supply 15 to the high-frequency antenna 13, an induced electric field is formed in the chamber 4, and the process supplied from the shower frame 11 is made to use this induced electric field. The gas is plasmatized to generate an inductively coupled plasma.

A substrate mounting table 30 on which a substrate G is mounted is provided on the bottom wall of the chamber 4 via an insulating member 26 made of insulating ceramics such as alumina. The detailed structure of the substrate mounting table 30 will be described later.

A plurality of exhaust ports 50 are provided on the bottom 4 b of the chamber 4 , and each exhaust port 50 is connected to an exhaust pipe 51 . The exhaust pipe 51 is connected to an exhaust device 52 , and a pressure regulating valve (not shown) is provided in the exhaust pipe 51 . The exhaust device 52 has a vacuum pump such as a turbomolecular pump, and thereby exhausts the inside of the chamber 4 to a predetermined vacuum degree.

In addition, a loading/unloading port 55 for loading and unloading the substrate G into and from the chamber 4 is provided on the side wall 4 a of the chamber, and the loading/unloading port 55 can be opened and closed by a gate valve 56 . A transfer chamber (not shown) is provided adjacent to the chamber 4 , and by opening the gate valve 56 , the substrate G can be loaded and unloaded through the loading and unloading port 55 by a transfer mechanism (not shown) provided in the transfer chamber.

In addition, the plasma processing apparatus 100 includes a control unit 60 including a microprocessor (computer) for controlling each component of the plasma processing apparatus 100 .

Next, a detailed configuration of the substrate mounting table 30 will be described.

The substrate mounting table 30 includes a base 31 disposed on the insulating member 26 , an electrostatic chuck 32 disposed on the base, and a side wall insulating member 33 covering the side walls of the base 31 and the electrostatic chuck 32 . The base body 31 and the electrostatic chuck 32 have a rectangular shape corresponding to the shape of the substrate G, and the entire substrate mounting table 30 is formed in a square plate shape or a column shape. The side wall insulating member 33 is made of insulating ceramics such as alumina.

The base body 31 includes an upper plate 35 on which an electrostatic chuck 32 is formed on an upper surface, and a lower plate 36 that supports the upper plate 35 .

Inside the lower plate 36, a temperature adjustment medium flow path 37 and a heater 38 are provided. The temperature regulation medium flow path 37 is connected to a temperature regulation medium flow pipe 39 , and the temperature regulation medium flow pipe 39 is connected to a temperature regulation medium supply unit 40 . Further, a temperature regulation medium at a predetermined temperature is supplied from the temperature regulation medium supply unit 40 to the temperature regulation medium flow path 37 via the temperature regulation medium flow pipe 39 . In addition, the heater 38 is connected to a heater power supply 41 , and the heater 38 generates heat by being supplied with power from the heater power supply 41 . The temperature adjustment medium flow path 37 , the heater 38 , the temperature adjustment medium flow pipe 39 , the temperature adjustment medium supply unit 40 , and the heater power supply 41 constitute a temperature adjustment mechanism of the substrate mounting table 30 . With such a temperature adjustment mechanism, the temperature of the lower plate 36 is adjusted to a predetermined temperature, and the temperature of the substrate G is adjusted from the lower plate 36 via the upper plate 35 and the electrostatic chuck 32 . In this embodiment, it is suitable when the temperature adjustment temperature by the temperature adjustment means exceeds 120 degreeC.

The temperature adjustment medium and the heater 38 can be used appropriately by adjusting the temperature according to the temperature. For example, the temperature adjustment medium is used until the temperature adjustment temperature reaches about 200° C., and the heater 38 is used when the temperature exceeds this temperature. When the temperature adjustment range is limited, only any one of the temperature adjustment medium flow path 37 and the heater 38 may be used as the temperature adjustment mechanism of the substrate mounting table 30 .

The electrostatic chuck 32 includes a dielectric layer 45 formed of a ceramic sprayed film formed on the surface of the upper plate 35 , that is, the surface of the base 31 , and a suction electrode 46 horizontally provided inside the dielectric layer 45 . The adsorption electrode 46 can adopt various forms such as a plate shape, a film shape, a grid shape, and a mesh shape. The adsorption electrode 46 is connected to a DC power supply 48 via a power supply line 47 , and a DC voltage is applied to the adsorption electrode 46 . The power supply to the adsorption electrode 46 is turned on and off by a switch (not shown). By applying a DC voltage to the adsorption electrode 46 , an electrostatic adsorption force such as Coulomb force or Johansen-Rabeck force is generated to adsorb the substrate G.

On the substrate mounting table 30, a plurality of lift pins (not shown) for transferring the substrate G are provided so as to protrude and sink relative to the upper surface of the substrate mounting table 30 (that is, the upper surface of the electrostatic chuck 32). Handing over of the lift pins is carried out with respect to the lift pins protruding upward from the upper surface of the substrate mounting table 30 . In addition, in a state where the substrate G is placed on the substrate mounting table 30 , a heat transfer gas for heat transfer is supplied between the substrate G and the substrate mounting table 30 . As the heat transfer gas, He gas having high heat transfer properties can be suitably used.

The upper plate 35 constituting at least a portion of the base body 31 that is in direct contact with the electrostatic chuck 32 is preferably made of martensitic stainless steel or ferritic stainless steel. Among them, martensitic stainless steel is more preferable.

The metal structure of martensitic stainless steel is mainly a martensite phase, and SUS403, SUS410, SUS420J1, and SUS420J2 are applicable to JIS standards. Examples of other martensitic stainless steels include SUS410S, SUS440A, SUS410F2, SUS416, SUS420F2, SUS431 and the like.

The metal structure of ferritic stainless steel is mainly ferrite phase, and SUS430 is applicable in JIS standard. Examples of other ferritic stainless steels include SUS405, SUS430LX, SUS430F, SUS443J1, SUS434, SUS444 and the like.

Martensitic stainless steel and ferritic stainless steel have a smaller coefficient of linear expansion than aluminum and austenitic stainless steel used as the existing substrate, and can also reduce the damage caused by the formation of stainless steel when used at high temperatures exceeding 120°C. The electrostatic chuck 32 on the surface is formed by the thermal pressure generated by the dielectric layer 45 of the ceramic spray coating.

For example, the linear expansion coefficient of aluminum is 23.8×10 ^-6 /°C, the linear expansion coefficient of austenitic stainless steel is 17.3×10 ^-6 /°C for SUS303 and SUS304, and 16×10 ^-6 /°C for SUS316 In contrast, the linear expansion coefficient of martensitic stainless steel is 10.4×10 ^-6 /℃ for SUS403 and SUS420J1, and 10.1×10 ^-6 /℃ for SUS410 and SUS440C. The linear expansion coefficient of ferritic stainless steel The coefficient is 11×10 ^-6 /°C for SUS430.

In addition, although the thermal conductivity of martensitic stainless steel and ferritic stainless steel is lower than that of aluminum, it is larger than that of austenitic stainless steel, and the temperature regulation effect is better than the case of using austenitic stainless steel.

For example, the thermal conductivity of aluminum is 138W/m·K, the thermal conductivity of austenitic stainless steel is 15W/m·K for SUS303 and SUS316, and 16.3W/m·K for SUS304. The thermal conductivity of body stainless steel is 25.1W/m·K for SUS403, 24.9W/m·K for SUS410, 30W/m·K for SUS420J1, and 24.3W/m·K for SUS440C. The thermal conductivity of element stainless steel is 26.4W/m·K when it is SUS430.

Among them, as a material having a very small coefficient of linear expansion and having a thermal conductivity suitable for the substrate 31, there are Ti and AlN, but both are expensive materials, and Ti is difficult to process, and AlN is difficult to make large parts, so it is not suitable as a material. The base of the substrate mounting table.

Since the lower plate 36 does not directly contact the electrostatic chuck 32 and has little influence on the thermal expansion of the dielectric layer 45, the lower plate 36 can be made of metal materials other than martensitic stainless steel and ferritic stainless steel, such as aluminum or austenitic stainless steel. It is particularly preferable to use aluminum, which has high thermal conductivity and is easy to control temperature. However, the lower plate 36 is made of martensitic stainless steel or ferritic stainless steel similarly to the upper plate 35 . In this case, it is preferably composed of martensitic stainless steel or ferritic stainless steel having the same composition as that of the upper plate 35 .

The ceramic sprayed coating constituting the dielectric layer 45 of the electrostatic chuck 32 can be obtained by spraying dielectric ceramics. Plasma spraying is preferable as the spraying method. As the ceramics constituting the dielectric layer 45, a dielectric having a resistivity capable of adsorbing the substrate by Coulomb force or Johansen-Rabeck force can be used, such as Al ₂ O ₃ (aluminum oxide), MgO·SiO ₂ (talc), 2MgO • SiO ₂ (forsterite), YF ₃ , Y ₂ O ₃ (yttrium oxide). In addition, the above-mentioned mixtures can also be used. In the case of thermal spraying, it is possible to form a mixture of arbitrary ratios by changing the compounding ratio of the powders to be sprayed. In addition, as such a mixture, at least one of Y ₂ O ₃ ·Al ₂ O ₃ ·SiO ₂ and Y ₂ O ₃ ·Al ₂ O ₃ ·SiO ₂ ·Si ₃ N ₄ can be used as the constituent dielectric. Layer 45 ceramic coating. In this case, the dielectric layer 45 may be composed of only at least one of Y ₂ O ₃ .Al ₂ O ₃ .SiO ₂ and Y ₂ O ₃ .Al ₂ O ₃ .SiO ₂ .Si ₃ N ₄ , however, The above materials are preferably used together with Al ₂ O ₃ (aluminum oxide), MgO·SiO ₂ (talc), 2MgO·SiO ₂ (forsterite), YF ₃ , Y ₂ O ₃ (yttrium oxide) or mixtures thereof For example, a laminated film (hybrid film).

On the other hand, since the temperature of the substrate mounting table 30 rises, stress occurs in the ceramic sprayed film (dielectric layer 45 ). The film stress σ at this time can be represented by the following formula (1).

σ=E×Δε=E×ΔT×Δα…(1)

Among them, E is the Young's modulus of the ceramic sprayed coating, Δε is the strain difference between the substrate (upper plate) and the ceramic sprayed coating, ΔT is the temperature difference, and Δα is the strain difference between the substrate (upper plate) and the ceramic sprayed coating. The coefficient of linear expansion of the film is poor.

When the film stress σ becomes large, cracks or film peeling of the ceramic sprayed coating constituting the dielectric layer 45 may occur. Therefore, it is necessary to make σ as small as possible. However, as shown in the above formula (1), the film stress σ Not only by simply reducing the linear expansion coefficient difference Δα between the substrate and the ceramic sprayed coating as shown in Patent Document 1, but also by reducing the Young’s modulus E and the linear expansion coefficient difference Δα of the coating itself to make it smaller, reducing The value of the product of the small Young's modulus E and the linear expansion coefficient difference Δα is important.

Then, when the value of the Young's modulus E of the film x the linear thermal expansion coefficient difference Δα is 2×10 ⁶ [(N/m ² )/°C] or less, the substrate mounting table 30 is heated to a temperature higher than 120°C. , It can also effectively prevent cracks and peeling in the dielectric layer (ceramic sprayed coating) of the electrostatic chuck. That is, it is preferably E×Δα≦2×10 ⁶ [(N/m ² )/°C]. Here, the part of the base body 31 that is in contact with the dielectric layer 45 is used as a reference for calculating the linear expansion coefficient difference Δα, which is the upper plate 35 in this embodiment.

In the combination of aluminum substrate and Al ₂ O ₃ (aluminum oxide) sprayed coating film that has been used in the past, the linear thermal expansion coefficient of aluminum is 23.8×10 ^-6 /°C, and the linear expansion coefficient of Al ₂ O ₃ is 6.4×10 ^-6 /℃, so Δα is 17.4×10 ^-6 /℃, the Young’s modulus E of Al ₂ O ₃ is 370×10 ⁹ N/m ² , so the value of E×Δα is 6.44×10 ⁶ [(N /m ² )/°C], which is a larger value. In addition, in the combination of austenitic stainless steel matrix and Al ₂ O ₃ , Δα is 10.9×10 ^-6 /℃, and the value of E×Δα is 4.03×10 ⁶ [(N/m ² )/℃], which is also larger value.

On the other hand, when the above-mentioned martensitic stainless steel is used as the substrate, Δα is 3.7×10 ^-6 to 4×10 ^-6 /°C in combination with the Al ₂ O ₃ (alumina) sprayed coating, The value of E×Δα is 1.37×10 ⁶ to 1.48×10 ⁶ [(N/m ² )/°C], which is a small value.

The linear expansion coefficients of MgO·SiO ₂ (talc), 2MgO·SiO ₂ (forsterite), YF ₃ , and Y ₂ O ₃ (yttrium oxide), which are other ceramic spray coating materials, are 7.7×10 ^-6 /°C, 12.5×10 ^-6 /°C, 13×10 ^-6 /°C, 8.2×10 ^-6 /°C. In addition, their Young's moduli were 120×10 ⁹ N/m ² , 150×10 ⁹ N/m ² , 41×10 ⁹ N/m ² , and 160×10 ⁹ N/m ² , respectively. As mentioned above, MgO·SiO ₂ (talc), 2MgO·SiO ₂ (forsterite), YF ₃ , and Y ₂ O ₃ (yttrium oxide) have a larger mean linear expansion coefficient than Al ₂ O ₃ (alumina). Since the modulus is low, it is more advantageous that the value of E×Δα is smaller than the case of using Al ₂ O ₃ (alumina) by using the above-mentioned material as the ceramic sprayed coating.

Martensitic stainless steel and ferritic stainless steel are preferably used as the substrate 31, and Al ₂ O ₃ (aluminum oxide), MgO·SiO ₂ (talc), 2MgO·SiO ₂ are preferably used as the ceramic sprayed coating material constituting the dielectric layer 45. (forsterite), YF ₃ , Y ₂ O ₃ (yttrium oxide), etc. However, when the value of Young's modulus E of the coating x linear thermal expansion coefficient difference Δα is 2 x 10 ⁶ [(N/m ² ) /°C] or less, other combinations can also be used.

Next, processing operations in the plasma processing apparatus 100 configured as described above will be described. The following processing operations are performed under the control of the control unit 60 .

First, the inside of the chamber 4 is exhausted by the exhaust device 52 to a predetermined pressure, the gate valve 56 is opened, and the substrate G is carried in from the loading and unloading port 55 by a conveying device not shown, and the lift pins not shown are raised. The substrate G is received thereon in the state in which it is placed, and the substrate G is placed on the substrate mounting table 30 by lowering the lift pins. After retracting the conveyance mechanism from the chamber 4, the gate valve 56 is closed.

In this state, the pressure inside the chamber 4 is adjusted to a predetermined degree of vacuum using a pressure regulating valve (not shown), and the processing gas is supplied from the processing gas supply system 20 through the gas supply pipe 20a and the shower frame 11. into the chamber 4.

At this time, the temperature of the substrate mounting table 30 is adjusted to a predetermined temperature by passing the temperature regulating medium through the temperature regulating medium flow path 37 in the lower plate 36 of the base body 31 or by supplying power to the heater 38, and the temperature on the back side of the substrate G is adjusted. A heat transfer gas such as He gas is supplied. At this time, when the plasma treatment is high-temperature treatment such as film formation treatment, the temperature of the substrate mounting table 30 is adjusted to a temperature exceeding 120° C., for example.

Next, a high frequency of, for example, 13.56 MHz is applied to the high frequency antenna 13 from the high frequency power supply 15 , whereby a uniform induced electric field is formed in the chamber 4 via the dielectric wall 2 . Using the induced electric field formed in this way, the process gas is plasmatized in the chamber 4, and high-density inductively coupled plasma is generated. Using this plasma, predetermined plasma processing such as film formation processing and etching processing is performed on the substrate G.

At this time, when it is necessary to heat the temperature of the substrate mounting table 30 to a temperature higher than 120° C., as in the conventional method, when aluminum or austenitic stainless steel is used as the substrate, as in the method of Patent Document 1, even if Even if the material of the ceramic sprayed coating constituting the dielectric layer 45 of the electrostatic chuck 32 is selected, the ceramic sprayed coating cannot follow the extension of the substrate, and it is difficult to effectively prevent the cracking of the dielectric layer.

In contrast, at least the part of the base 31 that is in contact with the electrostatic chuck 32, in this embodiment at least the upper plate 35, is made of martensitic stainless steel or ferritic stainless steel. By heating to a temperature higher than 120° C., the ceramic sprayed coating constituting the dielectric layer of the electrostatic chuck 32 can also follow the extension of the base 31 , and cracking and peeling of the ceramic sprayed coating can be prevented.

At this time, it was found that the stress generated in the ceramic sprayed film (dielectric layer 45) due to the temperature rise of the substrate mounting table 30 can be expressed by the above-mentioned formula (1), and that the film stress σ is not only expressed by simply Reduce the linear expansion coefficient difference Δα between the substrate and the ceramic spray coating, and also reduce the Young’s modulus E and the linear expansion coefficient difference Δα of the coating itself, thereby reducing the Young’s modulus E The value of the product of the difference Δα and the coefficient of linear expansion is important, and when the value of the Young's modulus E of the coating x the difference Δα of the coefficient of linear expansion is 2×10 ⁶ [(N/m ² )/°C] or less, even Even heating the substrate mounting table 30 to a temperature higher than 120° C. can effectively prevent cracking and peeling of the thermal sprayed coating (ceramic thermal sprayed coating) of the electrostatic chuck.

Moreover, by making the material of the base body 31 martensitic stainless steel or ferritic stainless steel, _Al2 , which has the smallest thermal expansion coefficient and the largest Young's modulus among the above-mentioned preferable materials, is used as the ceramic spray coating film constituting the dielectric layer 45. Also in the case of O ₃ (alumina), the value of the Young's modulus E of the coating x the linear thermal expansion coefficient difference Δα can be set to 2 x 10 ⁶ [(N/m ² )/°C] or less.

In addition, by making the value of the Young's modulus E of the coating x the linear thermal expansion coefficient difference Δα equal to or less than 2×10 ⁶ [(N/m ² )/°C] as described above, the heat resistance of the substrate mounting table 30 can be adjusted to 200°C or higher, further 250°C or higher.

In addition, martensitic stainless steel or ferritic stainless steel is used as the substrate 31, and as the material of the ceramic sprayed coating constituting the dielectric layer 45, a material having a larger linear expansion coefficient than Al ₂ O ₃ (alumina) and having a Young's modulus is used. When the amount of MgO·SiO ₂ (talc), 2MgO·SiO ₂ (forsterite), YF ₃ , Y ₂ O ₃ (yttrium oxide) is low, the Young's modulus E of the coating can be improved. The linear thermal expansion coefficient difference Δα The value of is 1×10 ⁶ [(N/m ² )/°C] or less. Therefore, higher heat resistance can be obtained, and the heat resistance of the substrate mounting table 30 can be more easily set to 250° C. or higher.

Next, in practice, a substrate mounting table (Structure A) with a structure combining an aluminum substrate and an Al ₂ O ₃ spray coating, and a substrate with a structure combining an austenitic stainless steel base and an Al ₂ O ₃ spray coating The heat-resistant temperature was evaluated on a mounting table (Structure B) and a substrate mounting table (Structure C) having a structure in which a martensitic stainless steel substrate and an Al ₂ O ₃ sprayed coating were combined. The heat-resistant temperature is a temperature at which damage is not caused to the ceramic sprayed coating when heating the substrate mounting table of each structure.

Table 1 shows a graph summarizing the combination of materials of the above-mentioned structures, the linear expansion coefficient difference Δα, the absolute value of the Young's modulus E×Δα of the film, and the heat resistance temperature. In addition, FIG. 2 shows the relationship between the linear expansion coefficient difference Δα and the heat resistance temperature and the relationship between Δα and E×Δα for the above structure.

【Table 1】

As shown in Table 1 and Figure 2, the results of the existing structure A and structure B are: Δα is larger than 10×10 ^-6 /°C, and the value (absolute value) of E×Δα is significantly more than 6.44×10 ⁶ Values of [(N/m ² )/°C], 4.03×10 ⁶ [(N/m ² )/°C] and 2×10 ⁶ [(N/m ² )/°C], each with a heat resistance temperature of 40°C , 120 ℃ lower. On the other hand, in structure C using martensitic stainless steel as a base, Δα is 3.7×10 ^-6 /10°C, and the value (absolute value) of E×Δα is smaller than 1.37×10 ⁶ [(N/m ² ) /°C] and 2×10 ⁶ [(N/m ² )/°C] are small, and therefore, the heat resistance temperature is 250°C, showing very high heat resistance compared with the prior art.

Next, it is considered to use martensitic stainless steel or ferritic stainless steel as the substrate, and use MgO·SiO ₂ , 2MgO·SiO ₂ , YF ₃ , Y ₂ as the material of the ceramic sprayed coating that constitutes the dielectric layer, other than Al ₂ O ₃ Structures D to K of O ₃ . Table 2 shows the materials of the substrates of structures D to K, the materials of the ceramic sprayed coatings, the difference in linear expansion coefficient Δα, and the values of the Young's modulus E×Δα of the coatings.

【Table 2】

As shown in Table 2, it was confirmed that by using martensitic stainless steel or ferritic stainless steel as a base, MgO·SiO ₂ and 2MgO·SiO ₂ , which have a larger linear expansion coefficient and a lower Young's modulus than Al ₂ O ₃ , YF ₃ , and Y ₂ O ₃ are used as materials for the ceramic sprayed coating that constitutes the dielectric layer, and the value of E×Δα can be lower than that of structure C, and it can be 1×10 ⁶ [(N/m ² )/°C] or less . From this result, the structures D to K can be expected to have a heat resistance temperature higher than 250° C. of the structure C, for example, a heat resistance temperature of 300° C. or higher.

Next, another embodiment of the present invention will be described.

3 is a cross-sectional view showing a substrate mounting table according to another embodiment of the present invention. The basic structure of this substrate mounting table 30 ′ is the same as that of the above-mentioned substrate mounting table 30 , but a high-frequency power supply 73 connected via a power supply line 71 is added to the base body 31 (lower plate 36 ). In addition, a matching unit 72 is attached to the power supply line 71 . The high-frequency power supply 73 functions to apply a high-frequency bias to the substrate G placed on the substrate stage 30' to introduce ions into the substrate G, and is effective when plasma processing is, for example, etching processing. In addition, as described above, by connecting the high-frequency power supply 73, instead of the inductively coupled plasma generating mechanism formed by the antenna 13, the high-frequency power supply 15, etc. of FIG. Coupled plasma generation mechanism.

At this time, it is preferable that the relative magnetic permeability of the material constituting the base body 31 to which high-frequency power is supplied is low. Martensitic stainless steel and ferritic stainless steel, which are preferable materials for the substrate 31, have relative magnetic permeability of 750 to 950 and 1000 to 1800, respectively, both of which can supply high-frequency power, but martensitic stainless steel with lower relative magnetic permeability is preferable. Body stainless steel.

<Other applications>

In addition, this invention is not limited to the said embodiment, Various deformation|transformation is possible within the scope of the idea of this invention. For example, in the above-mentioned embodiments, an example in which the substrate mounting table of the present invention is applied to an inductively coupled plasma processing apparatus has been described. Set the stage. As another plasma processing apparatus, a capacitively coupled plasma processing apparatus as described above can be used.

In addition, the present invention is not limited to a plasma processing apparatus, but can be generally applied to a substrate processing apparatus that places a substrate on a substrate stage and processes it. In addition, when the present invention can be used in an application in which the substrate stage is used at a high temperature of 120° C. or higher, it is not limited to the above-mentioned film formation treatment and etching treatment.

In addition, in the above-mentioned embodiment, the base body of the type divided into the upper plate and the lower plate was exemplified as the base body, but the base body may have an integral structure.

In addition, in the above-mentioned embodiment, the temperature adjustment is performed on the lower plate of the base body, however, the temperature adjustment mechanism may be provided outside the base body. In addition, the present invention can be applied to the treatment of the substrate stage at a temperature exceeding 120° C., and a temperature adjustment mechanism is not necessarily required.

In addition, the present invention can be generally applied to substrate mounting tables for mounting substrates other than glass substrates for FPDs. Among them, when the temperature exceeds 120°C, when the temperature exceeds 120°C, the substrate mounting table for mounting the glass substrate for FPD that is a rectangular substrate, especially the substrate mounting table for mounting a rectangular substrate with a side length of 700mm or more, will be damaged by the dielectric layer of the electrostatic chuck. The ceramic spray coating is prone to cracking and peeling. Therefore, the present invention is particularly effective on a substrate mounting table for mounting a rectangular substrate of such a size.

Claims (11)

1. a kind of substrate-placing platform, is used to load substrate in substrate board treatment, is used at a temperature of more than 120 DEG C, its In, the substrate board treatment is to processed substrate implementation processing in process container, and the substrate-placing platform is characterised by, Including：

Metal matrix；With

The electrostatic chuck of the processed substrate of absorption, its have be arranged on it is on described matrix, formed by ceramic spray coating Dielectric layer and the adsorption electrode for the inside for being arranged on the dielectric layer,

The part at least contacted with the dielectric layer of described matrix is made up of martensitic stain less steel or ferritic stainless steel.

2. substrate-placing platform as claimed in claim 1, it is characterised in that：

Also have via described matrix and the electrostatic chuck by the temperature adjustment of the processed substrate on the electrostatic chuck into The thermoregulation mechanism of set point of temperature, makes the substrate-placing platform turn into the temperature more than 120 DEG C using the thermoregulation mechanism Degree.

3. substrate-placing platform as claimed in claim 2, it is characterised in that：

Described matrix includes：The upper board contacted with the dielectric layer of the electrostatic chuck；And lower panel, it is arranged on institute State under upper board, temperature is adjusted by the thermoregulation mechanism, at least described upper board is by martensitic stain less steel or iron element Body stainless steel is constituted.

4. a kind of substrate-placing platform, is used to load substrate in substrate board treatment, is used at a temperature of more than 120 DEG C, its In, the substrate board treatment is to processed substrate implementation processing in process container, and the substrate-placing platform is characterised by, Including：

Metal matrix；With

The electrostatic chuck of the processed substrate of absorption, its have be arranged on it is on described matrix, formed by ceramic spray coating Dielectric layer and the adsorption electrode for the inside for being arranged on the dielectric layer,

Set the Young's modulus for the ceramic spray coating for constituting the dielectric layer as E, described matrix at least with it is described The feelings that the linear expansion coefficient difference of the ceramic spray coating of the part of dielectric layer contact with constituting the dielectric layer is Δ α Under condition, E × Δ α≤2 × 10 are met⁶[(N/m²)/℃]。

5. substrate-placing platform as claimed in claim 4, it is characterised in that：

Also have via described matrix and the electrostatic chuck by the temperature adjustment of the processed substrate on the electrostatic chuck into The thermoregulation mechanism of set point of temperature, makes the substrate-placing platform turn into the temperature more than 120 DEG C using the thermoregulation mechanism Degree.

6. substrate-placing platform as claimed in claim 5, it is characterised in that：

Described matrix includes：The upper board contacted with the dielectric layer of the electrostatic chuck；And lower panel, it is arranged on institute State under upper board, temperature is adjusted by the thermoregulation mechanism, in the institute for setting the upper board with constituting the dielectric layer The linear expansion coefficient difference of ceramic spray coating is stated in the case of Δ α, to meet E × Δ α≤2 × 10⁶[(N/m²)/℃]。

7. the substrate-placing platform as any one of claim 1 to 6, it is characterised in that：

The ceramic spray coating for constituting the dielectric layer is to be selected from Al₂O₃(aluminum oxide), MgOSiO₂(talcum), 2MgO SiO₂(forsterite), YF₃And Y₂O₃At least one of (yittrium oxide).

8. the substrate-placing platform as any one of claim 1 to 6, it is characterised in that：

The ceramic spray coating for constituting the dielectric layer is selected from MgOSiO₂(talcum), 2MgOSiO₂(forsterite), YF₃ And Y₂O₃(yittrium oxide).

9. the substrate-placing platform as any one of claim 1 to 6, it is characterised in that：

The ceramic spray coating for constituting the dielectric layer is obtained as any change of proportioning of the powder by spraying plating is carried out The Y of mixture₂O₃·Al₂O₃·SiO₂And Y₂O₃·Al₂O₃·SiO₂·Si₃N₄At least one.

10. the substrate-placing platform as any one of claim 1 to 6, it is characterised in that：

The ceramic spray coating for constituting the dielectric layer is by selected from Al₂O₃(aluminum oxide), MgOSiO₂(talcum), 2MgO SiO₂(forsterite), YF₃And Y₂O₃At least one and as the powder by spraying plating is carried out proportioning of (yittrium oxide) is any to be changed Obtained from mixture Y₂O₃·Al₂O₃·SiO₂And Y₂O₃·Al₂O₃·SiO₂·Si₃N₄At least one composition.

11. a kind of substrate board treatment, it is characterised in that including：

Process container for implementing processing to the substrate that is processed；

It is used to load the substrate-placing any one of claim 1 to the claim 10 of substrate in the process container Platform；

Processing gas feed mechanism to supplying processing gas in the process container；

The processing gas in the processing gas importing process container come will be supplied from the processing gas feed mechanism Introduction part；With

To the exhaust gear being exhausted in the process container.