Polishing method of substrate mounting table and substrate processing device

Abstract

The present invention provides a polishing method for a substrate stage and a substrate processing device. The polishing method can suppress the generation of steps due to machining misalignment caused by the inclination of a machining tool due to the influence of a cutting load during machining of the substrate stage, thereby suppressing the generation of etching spots. The polishing method for a substrate stage is used to polish a substrate mounting surface as the upper surface of a substrate stage, the substrate stage comprising a substrate, a lower sprayed film provided on the substrate, and an upper sprayed film provided on an electrode layer, the polishing method for a substrate stage having the following steps: applying an immersion treatment to the upper sprayed film and the lower sprayed film using an impregnating agent; applying a flattening treatment to the substrate mounting surface using a grinding process; and masking the peripheral portion of the substrate mounting surface and applying a roughening treatment to the central portion of the substrate mounting surface except the peripheral portion.

Description

Technical Field

[0001] The present invention relates to a polishing method of a substrate mounting table and a substrate processing device. Background Art

[0002] Patent Document 1 discloses a substrate stage having a substrate mounting surface formed by an insulating film and a smooth portion provided around the roughened portion, and a method for manufacturing the substrate stage. The substrate stage does not damage the substrate and can effectively suppress the generation of etching spots.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2011-119326 Summary of the invention

[0004] Problem that the invention aims to solve

[0005] The technology disclosed herein suppresses the occurrence of steps due to machining misalignment caused by inclination of a machining tool due to the influence of a cutting load during machining of a substrate mounting table, thereby suppressing the occurrence of etching spots.

[0006] Solutions for solving problems

[0007] A technical solution disclosed herein is a method for polishing a substrate mounting table, which is used to polish a substrate mounting surface serving as the upper surface of the substrate mounting table. The substrate mounting table includes a substrate, a lower sprayed film provided on the substrate, and an upper sprayed film provided on an electrode layer. The method for polishing the substrate mounting table has the following steps: applying an impregnation treatment to the upper sprayed film and the lower sprayed film using an impregnating agent; applying a flattening treatment to the substrate mounting surface using a grinding process; and masking the peripheral portion of the substrate mounting surface and applying a roughening treatment to the central portion of the substrate mounting surface excluding the peripheral portion.

[0008] Effects of the Invention

[0009] According to the present disclosure, the occurrence of steps due to machining deviation caused by inclination of a machining tool due to the influence of a cutting load during machining of a substrate mounting table can be suppressed, thereby suppressing the occurrence of etching spots. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is an explanatory diagram related to processing offset.

[0011] Figure 2 It is a longitudinal sectional view schematically showing the structure of the plasma processing apparatus according to the present embodiment.

[0012] Figure 3 It is a cross-sectional view schematically showing the structure of the plasma processing apparatus according to the present embodiment.

[0013] Figure 4It is an explanatory diagram regarding the polishing method of the mounting table according to the present embodiment.

[0014] Figure 5 It is an explanatory diagram of a polishing method of a mounting table according to a first other embodiment.

[0015] Figure 6 It is an explanatory diagram of a polishing method of a mounting table according to a second other embodiment. DETAILED DESCRIPTION

[0016] In the manufacturing process of a plasma flat panel display (FPD), a substrate as a processed object is subjected to plasma etching. In the plasma etching process, for example, in a processing container equipped with a pair of parallel flat electrodes (upper electrode and lower electrode), a substrate is placed on a substrate stage that functions as a lower electrode, and a high-frequency electric field is formed between the electrodes by applying high-frequency power to at least one of the electrodes. The plasma of the processing gas is formed by the high-frequency electric field, and the material film on the substrate is etched by the plasma. When the plasma etching process is repeated, etching products are generated, and the etching products sometimes adhere to and accumulate on the surface of the substrate stage. In this case, on the surface of the substrate stage, due to the presence of attachments, an area is generated where the attachments are between the back of the substrate and the front of the substrate stage, and the thermal conductivity and electrical conductivity differ between this area and the area where there are no attachments. As a result, a portion with a higher etching rate and a portion with a lower etching rate are formed on the surface of the substrate, and unevenness called etching spots is generated.

[0017] In recent years, the production of flexible panels has increased in FPD manufacturing equipment, and customers have become more demanding in terms of display spots on the panels. Therefore, it is necessary to process and grind the surface of the sprayed film (insulating film) sprayed on the surface of the substrate mounting table (lower electrode) into a more suitable shape (for example, flat on a macroscopic level and rough on a microscopic level). Patent document 1 discloses a structure in which a smoothing treatment is performed on the insulating film formed on the surface of the substrate mounting table, and then only the inner part of the insulating film is sandblasted to form a roughened portion, and the surrounding area is set as a smooth portion.

[0018] In the prior art, as a method for processing a sprayed film on the surface of a substrate mounting table, mechanical processing using a processing tool is known. In mechanical processing, there is a concern that the processing tool may tilt due to the influence of the cutting load during processing, resulting in a step formed on the surface, so-called processing misalignment. Figure 1 This is an illustration related to machining misalignment. Figure 1 As shown in (a), when cutting is performed using a processing tool 200, the processing tool is tilted due to cutting resistance, thereby forming a small step 203 on the surface of the substrate mounting table 202. Figure 1As shown in (b), when the etching product 204 is attached to the surface of the substrate mounting table 202 with a step 203 formed thereon, a temperature difference (temperature unevenness) is generated due to the difference in heat transfer corresponding to the position of the substrate caused by the step (refer to the large arrow and the small arrow in the figure), which may lead to the formation of etching spots.

[0019] Therefore, the technology disclosed in the present invention is to realize a substrate stage capable of suppressing the occurrence of machining misalignment due to mechanical machining using a machining tool during surface polishing of the substrate stage and effectively preventing the occurrence of etching spots.

[0020] Hereinafter, the structure of the plasma processing apparatus provided with the substrate mounting table of this embodiment will be described with reference to the drawings. In addition, in this specification, the same reference numerals are attached to the elements having substantially the same functional configuration, and the repeated description is omitted.

[0021] <Plasma processing equipment>

[0022] Figure 2 and Figure 3 Each of the diagrams is a longitudinal sectional view and a transverse sectional view schematically showing the structure of the plasma processing apparatus according to the present embodiment.

[0023] Figure 2 The plasma processing device 1 performs substrate processing, i.e., plasma processing, on a rectangular glass substrate G (hereinafter referred to as "substrate G") as a substrate using plasma of a processing gas. The plasma processing performed by the plasma processing device 1 is, for example, film forming processing, etching processing, ashing processing, etc. for FPD. By these processing, electronic devices such as light-emitting elements and driving circuits of light-emitting elements are formed on the substrate G.

[0024] The plasma processing apparatus 1 includes a container body 10 in the shape of a square tube with a bottom. The container body 10 is formed of a conductive material, such as aluminum, and is electrically grounded. Since plasma processing generally uses corrosive gases, the inner wall surface of the container body 10 is subjected to a corrosion-resistant coating treatment such as anodizing treatment for the purpose of improving corrosion resistance. In addition, an opening is formed on the upper surface of the container body 10. The opening is airtightly blocked by a rectangular metal window 20 insulated from the container body 10, specifically, by the metal window 20 and a metal frame 14 described later. The space enclosed by the container body 10 and the metal window 20 becomes a processing space S1 where a substrate G to be processed by plasma processing is located during plasma processing, and the space above the metal window 20 becomes an antenna chamber S2 in which a high-frequency antenna (plasma antenna) 90 described later is arranged. On the negative side (X direction) of the container body 10 Figure 2A side wall (on the left side) is provided with a feed-in port 11 and a gate valve 12. The feed-in port 11 is used to feed the substrate G into and out of the processing space S1, and the gate valve 12 opens and closes the feed-in port 11.

[0025] A substrate mounting table (hereinafter also simply referred to as a mounting table) 30 for mounting the substrate G is provided on the bottom wall 10a of the container body 10 in a manner opposite to the metal window 20. The mounting table 30 is formed, for example, in a rectangular shape when viewed from above. The mounting table 30 includes a table body 31, and the upper surface of the table body 31 serves as a mounting surface for the substrate G. A base material 36 is provided at the lower part of the table body 31, and the base material 36 is formed of a conductive material, such as aluminum or an aluminum alloy. The base material 36 is mounted on an insulating member 32 formed of an insulating material, and the table body 31 is provided on the bottom wall 10a of the container body 10 via the base material 36 and the insulating member 32.

[0026] A power supply member 44 is connected to the lower surface of the substrate 36. A high-frequency power supply 41 as a bias power supply is connected to the power supply member 44 via a matching device 40. The high-frequency power supply 41 supplies high-frequency power for bias, for example, high-frequency power with a frequency of 3.2 MHz, to the stage body 31. Thus, an RF bias is generated, and ions in the plasma generated in the processing space S1 can be attracted to the substrate G. In this way, the mounting table 30 forms a bias electrode that generates an RF bias.

[0027] like Figure 2 As shown in FIG. 1 , a step portion is formed by the outer periphery of the stage body 31, the outer periphery of the substrate 36, and the upper portion of the insulating member 32, and a rectangular focus ring 37 is formed on the step portion. The focus ring 37 is formed of ceramic such as alumina. When the substrate G is placed on the upper surface of the stage body 31, the end of the upper surface of the focus ring 36 on the mounting stage side is covered by the outer periphery of the substrate G.

[0028] The substrate 36 is provided with a temperature control medium flow path 47a that meanders to cover the entire plane area. Both ends of the temperature control medium flow path 47a are connected to a delivery pipe 47b and a return pipe 47c. The delivery pipe 47b supplies the temperature control medium to the temperature control medium flow path 47a, and the return pipe 47c discharges the temperature control medium that has been heated by flowing through the temperature control medium flow path 47a. Figure 2As shown, the delivery pipe 47b is connected to the delivery flow path 51, the return pipe 47c is connected to the return flow path 52, and the delivery flow path 51 and the return flow path 52 are connected to the refrigerator 50. The refrigerator 50 has a main body for controlling the temperature of the temperature control medium and the discharge flow rate, and a pump for pressurizing and conveying the temperature control medium (all not shown). In addition, a refrigerant is used as the temperature control medium, and the refrigerant is Galden (registered trademark), Fluorinert (registered trademark), etc. The temperature control form of the example in the figure is a form in which the temperature control medium is circulated in the substrate 36, but it can also be a form in which a heater is built into the substrate 36 and the temperature is controlled by the heater, or it can be a form in which the temperature control medium and the heater are used for temperature control. In addition, the heater can also be replaced by circulating a high-temperature temperature control medium and performing temperature control accompanied by heating. In addition, the heater as a resistor is formed by tungsten, molybdenum, or a compound of any of these metals and aluminum oxide, titanium, etc. In addition, although the temperature control medium flow path 47 a is formed in the base material 36 in the example shown in the figure, for example, the stage main body 31 may have the temperature control medium flow path.

[0029] The stage body 31 includes a lower sprayed film 33 formed of a dielectric material, such as ceramics such as alumina, and an upper sprayed film 34 provided on the lower sprayed film 33. The upper sprayed film 34 is formed by a spraying method of spraying ceramics such as alumina or a metal-ceramic composite. The upper surface of the upper sprayed film 34 serves as a substrate mounting surface 35 on which the substrate G is mounted. The substrate mounting surface 35 includes a roughened portion 35a having a relatively rough surface with a surface roughness Ra of, for example, 1 μm or more and 6 μm or less, and a smooth portion 35b surrounding the roughened portion 35a and having a surface roughness Ra of less than 2 μm. That is, the substrate mounting surface 35 includes a roughened portion 35a (hereinafter also referred to as a central portion) as a central portion and a smooth portion 35b (hereinafter also referred to as a peripheral portion) as a peripheral portion.

[0030] The roughened portion 35a has fine concavo-convex portions and supports the back side of the substrate G without causing damage by contacting the substrate G at multiple points on the convex portions. Moreover, even when etching products adhere to the roughened portion 35a, the etching products can be captured in the concave portions on the surface. Regarding the smooth portion 35b, when the substrate G is placed on the mounting table 30, the back side of the peripheral portion of the substrate G is closely attached to the front side of the smooth portion 35b, so that the substrate G can be stably placed on the mounting table 30. With such a structure, a closed space can be formed between the substrate G and the roughened portion 35a of the upper layer sprayed film 34. In particular, when a heat transfer gas is supplied to the back side of the substrate G for temperature control, the heat transfer gas can be sealed on the back side of the substrate G, thereby improving the heat transfer efficiency.

[0031] In addition, the surface roughness Ra refers to the arithmetic mean roughness specified in JIS B0601-1994, which refers to a reference length determined by the roughness curve in the direction of its mean line, and the absolute values ​​of the deviations from the mean line to the measured roughness curve are summed and averaged within the reference length, and the value is expressed in micrometers (μm).

[0032] In addition, the stage main body 31 is provided with an electrode layer 31a constituting an electrostatic chuck for adsorbing and holding the substrate G. A DC power supply 46 is connected to the electrode layer 31a via a power supply line 45. A DC voltage is applied from the DC power supply 46 to the electrode layer 31a to generate a Coulomb force, and the substrate G is held in a state of being placed on the stage main body 31 by the Coulomb force.

[0033] In addition, an exhaust port 13 is formed in the bottom wall 10a of the container body 10. A plurality of exhaust ports 13 are provided along each side of the mounting table 30 which is rectangular in plan view. Figure 2 As shown, an exhaust unit 60 including a vacuum pump or the like is connected to the exhaust port 13. The exhaust unit 60 is used to decompress the processing space S1. The exhaust unit 60 may be provided at each of the plurality of exhaust ports 13 or may be provided in common for the plurality of exhaust ports 13.

[0034] A metal frame 14 is provided on the upper surface side of the side wall of the container body 10. The metal frame 14 is a rectangular frame body formed of a metal material such as aluminum. A sealing member 15 for keeping the processing space S1 airtight is provided between the container body 10 and the metal frame 14. The container body 10, the metal frame 14, and the metal window 20 constitute a processing container having a mounting table 30 provided therein.

[0035] The metal window 20 is divided into a plurality of partial windows 21 . The partial windows 21 are arranged inside the metal frame 14 , and the metal window 20 as a whole is in a rectangular shape.

[0036] The partial windows 21 function as showerheads for supplying processing gas to the processing space S1. For example, each partial window 21 is formed with a plurality of gas ejection holes 21a for ejecting processing gas downward and a diffusion chamber 21b for diffusing the processing gas, and the gas ejection holes 21a are connected to the diffusion chamber 21b.

[0037] The diffusion chamber 21b of each local window 21 is connected to a processing gas supply unit 71 via a gas supply pipe 70. The processing gas supply unit 71 includes a flow rate adjustment valve (not shown), an opening and closing valve (not shown), etc., and supplies processing gases required for film forming, etching, ashing, etc. to the diffusion chamber 21b. Figure 2 FIG. 4 shows a state in which the processing gas supply unit 71 is connected to one partial window 21 , but in reality, the processing gas supply unit 71 is connected to the diffusion chamber 21 b of each partial window 21 .

[0038] In addition, the partial windows 21 are electrically insulated from the metal frame 14 by the insulating member 22 , and adjacent partial windows 21 are also electrically insulated from each other by the insulating member 22 .

[0039] The insulating member 22 is provided with an insulating member cover 23 for protecting the insulating member 22 and covering the surface of the insulating member 22 on the processing space S1 side.

[0040] Furthermore, a top plate portion 80 is disposed above the metal window 20 . The top plate portion 80 is supported by a side wall portion 81 provided on the metal frame 14 .

[0041] Furthermore, the partial window 21 constituting the metal window 20 is suspended from the top plate portion 80 via a suspension member (not shown).

[0042] The space surrounded by the metal window 20 , the side wall portion 81 , and the top plate portion 80 constitutes an antenna chamber S2 . A high-frequency antenna 90 is disposed inside the antenna chamber S2 so as to face the partial window 21 .

[0043] The high frequency antenna 90 is arranged to be separated from the partial window 21 via a spacer (not shown) formed of, for example, an insulating material. The high frequency antenna 90 is formed as a multi-ring antenna having a plurality of concentrically formed antennas, for example, in a spiral shape, along the surface corresponding to each partial window 21, so as to surround the circumference of the rectangular metal window 20.

[0044] A high frequency power source 43 is connected to each high frequency antenna 90 via a matching device 42. A high frequency power of, for example, 13.56 MHz is supplied from the high frequency power source 43 to each high frequency antenna 90 via the matching device 42. Thus, during the plasma processing, an eddy current is generated on the surface of each local window 21, and an induced electric field is formed inside the processing space S1 due to the eddy current. The processing gas ejected from the gas ejection hole 21a is plasmatized inside the processing space S1 due to the induced electric field.

[0045] In addition, a control unit U is provided in the plasma processing device 1. The control unit U is, for example, a computer having a CPU, a memory, etc., and has a program storage unit (not shown). The program storage unit stores a program for controlling the processing of the substrate G at the plasma processing device 1. The above-mentioned program is stored in a computer-readable storage medium, and can also be loaded into the control unit U from the storage medium. Part or all of the program can also be implemented by dedicated hardware (circuit board). In addition, the above-mentioned storage medium can be either temporary or non-temporary.

[0046] <Substrate processing>

[0047] Next, the substrate processing by the plasma processing apparatus 1 will be described. In addition, under the control of the control unit U, the following substrate processing is performed.

[0048] First, the gate valve 12 is opened, and the substrate G is carried into the processing space S1 from the carrying port 11 and mounted on the mounting table 30. Then, the gate valve 12 is closed.

[0049] Next, the processing gas is supplied from the processing gas supply unit 71 into the processing space S1 through the diffusion chamber 21b of each local window 21. In addition, the processing space S1 is exhausted by the exhaust unit 60, and the processing space S1 is adjusted to a desired pressure.

[0050] Next, high frequency power is supplied from the high frequency power supply 43 to the high frequency antenna 90, thereby generating a uniform induction electric field in the processing space S1 through the metal window 20. As a result, the processing gas in the processing space S1 is plasmatized by the induction electric field, and a high-density inductively coupled plasma is generated. Then, by the high frequency power for bias supplied from the high frequency power supply 41 to the stage main body 31 of the mounting stage 30, ions in the plasma are attracted to the substrate G, and the substrate G is subjected to plasma processing.

[0051] After the plasma processing is completed, the power supply from the high frequency power supplies 41 and 43 and the supply of the processing gas from the processing gas supply unit 71 are stopped, and the substrate G is carried out in the reverse order of the introduction.

[0052] Thus, a series of substrate processing is completed.

[0053] <Polishing method of substrate mounting table>

[0054] Next, a method of polishing the mounting table 30 will be described with reference to the drawings. Figure 4 1 is an explanatory diagram of a method for polishing a mounting table (substrate mounting surface) according to the present embodiment. Figure 4 As shown in (a), a structure A1 is prepared, which includes a lower sprayed film 33, an electrode layer 31a, and an upper sprayed film 34 formed as an upper layer by spraying on the upper surface of the lower sprayed film 33 and the electrode layer 31a. Then, in order to prevent the penetration of the grinding fluid in the next process, the lower sprayed film 33, the electrode layer 31a, and the upper sprayed film 34 are impregnated with an impregnating agent. Here, as the impregnating agent, for example, a first impregnating agent with a low filling rate such as fluororesin, silicone resin, silicate, etc. can be used, or a second impregnating agent with a high filling rate such as acrylic, epoxy resin, polyurethane, etc. can also be used.

[0055] Then, if Figure 4 As shown in (b), the entire substrate mounting surface 35 is subjected to a grinding process as a flattening process using a grinding device (not shown) such as a surface grinder 100. Thus, the entire substrate mounting surface 35 is evenly smoothed, and the surface roughness Ra of the upper surface of the upper layer sprayed film 34 is less than 2 μm.

[0056] Then, if Figure 4 As shown in (c), the central portion 35a is roughened while the peripheral portion 35b of the substrate mounting surface 35 is protected by the mask 103. The roughening treatment is, for example, sandblasting performed by a sandblasting device 105. In the sandblasting, the upper sprayed film 34 of the central portion 35a can be dug into. The amount of digging into the upper sprayed film produced by the digging treatment is, for example, 30 μm to 50 μm. By means of the roughening treatment, the surface roughness Ra of only the central portion 35a of the substrate mounting surface 35 is made to be greater than 1 μm and less than 6 μm. Examples of the sandblasting materials used for the sandblasting process include aluminum oxide, silicon carbide, and zirconium oxide.

[0057] According to the above steps, the central portion 35a of the substrate mounting surface 35 is formed as a roughened portion 35a having a predetermined surface roughness, and the peripheral portion 35b protected by the mask 103 is formed as a smooth portion 35b flatter than the roughened portion 35a.

[0058] <Effects of the technology disclosed herein>

[0059] According to the polishing method of this embodiment, a roughened portion 35a having a predetermined surface roughness is formed on the substrate mounting surface 35, and a smooth portion 35b is formed on the periphery of the substrate mounting surface 35. Since machining using a processing tool is not used during polishing, there is no concern about the so-called processing misalignment, in which the processing tool is tilted due to the influence of the cutting load during processing, resulting in the formation of steps on the surface. That is, the generation of etching spots caused by processing misalignment can be suppressed.

[0060] Furthermore, when the substrate mounting surface 35 is mounted on the substrate G, the substrate G is in close contact with the smooth portion 35b, and a convex portion is formed on the roughened portion 35a, so that a closed space is formed between the substrate G and the roughened portion 35a of the upper layer sprayed film 34. Thus, when a heat transfer gas is supplied to the back side of the substrate G to control the temperature, the heat transfer gas can be sealed on the back side of the substrate G, so that the heat transfer efficiency can be improved.

[0061] It should be understood that the embodiments disclosed this time are illustrative in all aspects and are not restrictive. The above embodiments can be omitted, replaced, and changed in various forms without departing from the scope of the claims and their gist. Other embodiments of the present disclosure are described below with reference to the accompanying drawings and the like. In addition, in the following other embodiments, the same figure marks are used for the structural elements having the same functional configuration as the above embodiments, and their descriptions are omitted.

[0062] <First other embodiment of the present disclosure>

[0063] Next, refer to Figure 5A first other embodiment of the present disclosure will be described. Figure 5 1 is an explanatory diagram of a method for polishing a mounting table (substrate mounting surface) according to another embodiment of the present invention. Figure 5 As shown in (a), a structure A2 is prepared, which includes a lower sprayed film 33, an electrode layer 31a, and an upper sprayed film 34 formed as an upper layer by spraying on the upper surface of the lower sprayed film 33 and the electrode layer 31a. Then, in order to prevent the infiltration of the grinding fluid in the next step and to improve the interface adhesion with the bank sprayed film 120 described later, the lower sprayed film 33, the electrode layer 31a, and the upper sprayed film 34 are impregnated with an impregnating agent. The impregnating agent used here is a first impregnating agent with a low filling rate such as fluororesin, silicone resin, silicate, etc.

[0064] Then, if Figure 5 As shown in (b) of FIG. 1 , a grinding device (not shown) having a surface grinder 100 is used to grind the entire substrate mounting surface 35 as a flattening process. Figure 5 As shown in (c), while the central portion 35a is protected by a mask 110, a ceramic such as aluminum oxide or a metal-ceramic composite is sprayed on the peripheral portion 35b to form a bank sprayed film 120. In order to prevent the infiltration of the grinding fluid in the next step and to prevent the bank sprayed film 120 from peeling off, the entire substrate mounting surface including the bank sprayed film 120 is impregnated with an impregnating agent. The impregnating agent used here is a second impregnating agent with a high filling rate such as acrylic, epoxy resin, and polyurethane.

[0065] Then, if Figure 5 As shown in (d) of FIG. 1 , a grinding device (not shown) having a surface grinder 100 is used to grind the surface of the bank spray coating 120 as a flattening process. Figure 5 As shown in (e), the center portion 35a is roughened while the flattened bank spray film 120 is protected by a mask 125. The roughening treatment is performed, for example, using a spraying device 130 in a spraying method called in-plane roughening spraying. In order to close the formed pores and ensure corrosion resistance and withstand voltage performance, an impregnation treatment is performed using an impregnating agent after the roughening treatment. The impregnating agent used here is a second impregnating agent with a high filling rate such as acrylic, epoxy resin, polyurethane, etc.

[0066] According to the above steps, the central portion 35a of the substrate mounting surface 35 is formed as a roughened portion 35a having a predetermined surface roughness, and the peripheral portion 35b protected by the mask 125 after the planarization process is formed as a smooth portion 35b flatter than the roughened portion 35a.

[0067] According to the grinding method of the first other embodiment, Figure 5(a) Figure 5 In the pre-polishing process shown in (b), in order to improve the interface adhesion between the upper spray coating 34 and the bank spray coating 120, an impregnation treatment using a first impregnating agent with a low filling rate such as fluororesin, silicone resin, silicate, etc. is performed. Figure 5 (c)~ Figure 5 In the latter step of polishing shown in (e), in order to improve the corrosion resistance and voltage resistance of the substrate mounting table 30, an impregnation treatment using a second impregnating agent with a high filling rate such as acrylic, epoxy resin, polyurethane, etc. is performed. Thus, in addition to the effects described in the above embodiment, a mounting table 30 having a substrate mounting surface with better corrosion resistance and voltage resistance is realized.

[0068] <Second other embodiment of the present disclosure>

[0069] Next, refer to Figure 6 , describing a second other embodiment of the present disclosure. Figure 6 2 is an explanatory diagram of a method for polishing a mounting table (substrate mounting surface) according to another embodiment of the present invention. Figure 6 As shown in (a), a structure A3 is prepared, which includes a lower sprayed film 33, an electrode layer 31a, and an upper sprayed film 34 formed as an upper layer by spraying on the upper surface of the lower sprayed film 33 and the electrode layer 31a. Then, in order to prevent the penetration of the grinding fluid in the next process, the lower sprayed film 33, the electrode layer 31a, and the upper sprayed film 34 are impregnated with an impregnating agent. The impregnating agent used here is a second impregnating agent with a high filling rate such as acrylic, epoxy resin, polyurethane, etc.

[0070] Then, if Figure 6 As shown in (b) of FIG. 1 , a grinding device (not shown) having a surface grinder 100 is used to grind the entire substrate mounting surface 35 as a flattening process. Figure 6 As shown in (c), the central portion 35a of the substrate mounting surface 35 is subjected to a process of digging into the upper-layer thermal sprayed film 34 (pit digging process) by sand blasting using a sand blasting device 105 in the central portion 35a.

[0071] Then, if Figure 6 As shown in (d), the central portion 35a is roughened while the peripheral portion 35b is protected by the mask 135. The roughening treatment is performed, for example, by a spraying method called in-plane roughening spraying using the spraying device 130. In order to close the formed pores and ensure corrosion resistance and withstand voltage performance, an impregnation treatment is performed using an impregnating agent after the roughening treatment. The impregnating agent used here is a second impregnating agent with a high filling rate such as acrylic, epoxy resin, polyurethane, etc.

[0072] According to the above steps, the central portion 35a of the substrate mounting surface 35 is configured as the roughened portion 35a having a predetermined surface roughness, and the peripheral portion 35b is configured as the smoothed portion 35b which is flatter than the roughened portion 35a.

[0073] According to the polishing method of the second other embodiment, in addition to the effects described in the above embodiment, a mounting table 30 having a substrate mounting surface with better corrosion resistance and withstand voltage performance is realized.

Claims

1. A method for polishing a substrate mounting table, which is used for polishing a substrate mounting surface as an upper surface of the substrate mounting table, the substrate mounting table comprising a substrate, a lower layer sprayed film provided on the substrate, and an upper layer sprayed film provided on an electrode layer, wherein: The polishing method of the substrate mounting table comprises the following steps: Applying a first immersion treatment to the upper sprayed film and the lower sprayed film using a first immersion agent; After the step of applying the first immersion treatment, the entire substrate mounting surface is subjected to a first flattening treatment by grinding using a grinding fluid; After the first planarization treatment, a second immersion treatment is performed on the entire substrate mounting surface including the bank sprayed film formed only on the peripheral edge of the substrate mounting surface using a second impregnating agent having a higher filling rate than the first impregnating agent; After the second immersion treatment, the bank sprayed film is subjected to a second planarization treatment by grinding using the grinding fluid; The peripheral edge of the substrate mounting surface is masked, and the central portion of the substrate mounting surface other than the peripheral edge is roughened by spraying; as well as After the step of applying the roughening treatment, a third impregnation treatment after the roughening is applied using the second impregnating agent.

2. The method for polishing a substrate mounting table according to claim 1, wherein: The step of applying the roughening treatment includes a process of digging into the upper sprayed film by sandblasting.

3. A substrate processing device, comprising a substrate mounting table, wherein: The substrate mounting table comprises a substrate, a lower layer sprayed film provided on the substrate, and an upper layer sprayed film provided on the electrode layer, and the upper surface of the substrate mounting table is configured as a substrate mounting surface. The substrate processing device grinds the substrate mounting surface by the following steps: Applying a first immersion treatment to the upper sprayed film and the lower sprayed film using a first immersion agent; After the step of applying the first immersion treatment, the entire substrate mounting surface is subjected to a first flattening treatment by grinding using a grinding fluid; After the first planarization treatment, a second immersion treatment is performed on the entire substrate mounting surface including the bank sprayed film formed only on the peripheral edge of the substrate mounting surface using a second impregnating agent having a higher filling rate than the first impregnating agent; After the second immersion treatment, the bank sprayed film is subjected to a second planarization treatment by grinding using the grinding fluid; The peripheral edge of the substrate mounting surface is masked, and the central portion of the substrate mounting surface other than the peripheral edge is roughened by spraying; as well as After the step of applying the roughening treatment, a third impregnation treatment after the roughening is applied using the second impregnating agent.

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