Substrate processing system and processing container cleaning method

Abstract

To provide a substrate processing system having heat resistance and corrosion resistance, and a cleaning processing method.SOLUTION: A substrate processing system 100 is capable of applying substrate processing using plasma to a substrate G and applying cleaning processing using plasma to a processing container 20. The substrate processing system comprises: a supply source 64 which supplies a process gas; a supply source 220 which supplies a cleaning gas; a plasma generation unit capable of generating plasma of the process gas or the cleaning gas; a substrate mounting table 70 on which the substrate is mounted; and a control unit 90 which performs control so as to implement the processing at 200°C or higher and 260°C or lower. The mounting table includes: a base material 71 of which the surface is coated with a nickel containing plating layer and which includes a mounting surface; a ceramic spray coating 74 which is formed on the nickel containing plating layer on the mounting surface of the base material; and an electrostatic adsorption electrode 75 which is embedded within the ceramic spray coating. The cleaning gas is a fluorine containing gas, and the base material is composed of martensite-based stainless steel.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a substrate processing system and a method for cleaning a processing vessel. [Background technology]

[0002] Patent Document 1 discloses that an electrostatic chuck is formed by using martensitic stainless steel as a base material and by ceramic spray coating. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-147278 A Summary of the Invention [Problem to be solved by the invention]

[0004] In one aspect, the present disclosure provides a heat-resistant and corrosion-resistant substrate processing system and method for cleaning a processing vessel. [Means for solving the problem]

[0005] In order to solve the above problems, according to one aspect, there is provided a substrate processing system capable of performing substrate processing on a substrate inside a processing vessel using plasma of a processing gas and performing a cleaning processing on the processing vessel using plasma of a cleaning gas, the system including at least a processing gas supply source connected to the processing vessel and supplying the processing gas, a cleaning gas supply source connected to the processing vessel and supplying the cleaning gas, a plasma generating unit capable of generating plasma of the processing gas or plasma of the cleaning gas, a substrate mounting stage provided inside the processing vessel and on which the substrate is mounted, and and a control unit that controls the substrate processing and the cleaning processing, wherein the substrate mounting table comprises a base material whose surface is covered with a nickel-containing plating layer and has a mounting surface on which the substrate is mounted, a ceramic sprayed coating formed on the nickel-containing plating layer on the mounting surface of the base material, and an electrostatic adsorption electrode embedded inside the ceramic sprayed coating, wherein the cleaning gas is a fluorine-containing gas, the base material is made of martensitic stainless steel, and the control unit controls the substrate processing to be performed at a temperature of 200°C or higher and 260°C or lower. Effect of the Invention

[0006] According to one aspect, the present disclosure can provide a substrate processing system and a method for cleaning a processing vessel having heat resistance and corrosion resistance. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 illustrates an example of a processing system according to an embodiment. [Diagram 2] 4 is a flowchart showing an example of an operation of the plasma processing apparatus. [Diagram 3] FIG. 2 is a schematic cross-sectional view showing an example of a substrate mounting table according to the embodiment. [Figure 4] FIG. 11 is a schematic cross-sectional view showing an example of a substrate mounting table according to a reference example. [Diagram 5] 11 is a graph showing a structure created to simulate the substrate mounting table according to the embodiment, and composition ratios of the structure after cleaning treatment; [Figure 6] 13 is a graph showing a structure created to simulate the substrate mounting table according to the reference example, and a composition ratio after the structure is cleaned. [Figure 7] An example of a graph showing heat resistance temperature and whether or not a material can withstand high-temperature F radicals. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. In the drawings, the same components are denoted by the same reference numerals, and duplicated descriptions may be omitted.

[0009] [Plasma processing equipment] A plasma processing apparatus 100 (substrate processing system) will be described with reference to Fig. 1. Fig. 1 is a vertical cross-sectional view showing an example of the plasma processing apparatus 100.

[0010] The plasma processing apparatus 100 shown in FIG. 1 is an inductively coupled plasma (ICP) processing apparatus that performs various substrate processing methods on a rectangular substrate G (hereinafter simply referred to as a substrate) for a flat panel display (hereinafter referred to as an FPD) in plan view. The substrate is mainly made of glass, and transparent synthetic resin may be used depending on the application. The substrate processing includes a film formation process using a chemical vapor deposition (CVD) method, an etching process, and the like. Examples of FPDs include a liquid crystal display (LCD), an electroluminescence (EL), and a plasma display panel (PDP). The substrate includes a form in which a circuit is patterned on its surface, as well as a support substrate. The planar dimensions of FPD substrates are becoming larger with each generation, and the planar dimensions of the substrate G processed by the plasma processing apparatus 100 include at least dimensions ranging from about 1500 mm×1800 mm for the sixth generation to about 3000 mm×3400 mm for the 10.5th generation. The thickness of the substrate G is about 0.2 mm to several mm.

[0011] 1 includes a processing vessel 20 having a rectangular box shape, a substrate mounting stage (mounting stage) 70 having a rectangular outer shape in a plan view that is disposed in the processing vessel 20 and on which a substrate G is mounted, and a control unit 90. The processing vessel may have a shape such as a cylindrical box or an elliptical cylindrical box, and in this embodiment, the substrate mounting stage is also circular or elliptical, and the substrate mounted on the substrate mounting stage is also circular or the like.

[0012] Processing vessel 20 is divided into two spaces, upper and lower, by metal window 30, with antenna chamber A, which is the upper space, being formed by upper chamber 13, and processing chamber S, which is the lower space, being formed by lower chamber 17. In processing vessel 20, a rectangular ring-shaped support frame 14 is disposed at the boundary between upper chamber 13 and lower chamber 17 so as to protrude into the inside of processing vessel 20, and metal window 30 is attached to support frame 14.

[0013] An upper chamber 13 forming the antenna room A is formed by a side wall 11 and a top plate 12, and is formed as a whole from a metal such as aluminum or an aluminum alloy.

[0014] The lower chamber 17 having the processing space S therein is formed by a side wall 15 and a bottom plate 16, and is made of a metal such as aluminum or an aluminum alloy as a whole. The side wall 15 is grounded by a ground wire 21.

[0015] The support frame 14 is formed from a metal such as conductive aluminum or an aluminum alloy, and can also be called a metal frame.

[0016] A rectangular annular (endless) seal groove 22 is formed at the upper end of the side wall 15 of the lower chamber 17, and a seal member 23 such as an O-ring is fitted into the seal groove 22. The seal member 23 is held by the abutting surface of the support frame 14, thereby forming a seal structure between the lower chamber 17 and the support frame 14.

[0017] A loading / unloading port 15a for loading / unloading a substrate G into / from the lower chamber 17 is provided in the side wall 15 of the lower chamber 17, and the loading / unloading port 15a is configured to be freely opened and closed by a gate valve 24. A transfer chamber (neither shown) containing a transfer mechanism is adjacent to the lower chamber 17, and the gate valve 24 is controlled to open and close, and the substrate G is loaded and unloaded by the transfer mechanism through the loading / unloading port 15a.

[0018] In addition, a plurality of exhaust ports 16a are provided in the bottom plate 16 of the lower chamber 17. In the lower chamber 17, the side wall 15 of the processing vessel 20 that houses the substrate mounting table 70 is formed in a rectangular cylindrical shape. In other words, the processing vessel 20 is formed in a rectangular horizontal cross section at least at the position of the lower chamber 17 that houses the substrate mounting table 70. In addition, the substrate mounting table 70 is formed in a rectangular shape when viewed from above in a plan view. In other words, the substrate mounting table 70 is formed in a rectangular horizontal cross section. A plurality of exhaust ports 16a are arranged around the substrate mounting table 70 in the bottom plate 16 of the processing vessel 20. In other words, the exhaust ports 16a are arranged outside the substrate mounting table 70 and inside the side wall 15 of the processing vessel 20 (lower chamber 17) when viewed in a plan view.

[0019] Each exhaust port 16a is connected to an exhaust device 300. A pressure gauge (not shown) is provided at an appropriate position in the lower chamber 17, and monitor information from the pressure gauge is transmitted to the control unit 90.

[0020] The substrate mounting table 70 includes a base material 71 and an electrostatic chuck 76 formed on an upper surface 71 a of the base material 71 .

[0021] The base material 71 has a rectangular shape in a plan view, and has planar dimensions approximately equal to those of the substrate G mounted on the substrate mounting table 70. The length of the long side of the base material 71 can be set to approximately 1800 mm to 3400 mm, and the length of the short side can be set to approximately 1500 mm to 3000 mm. With respect to these planar dimensions, the thickness of the base material 71 can be, for example, approximately 50 mm to 100 mm.

[0022] A temperature control medium flow passage 72a that meanders so as to cover the entire area of ​​a rectangular plane is provided in the base material 71. The temperature control medium flow passage may be provided in a temperature control plate that is a separate component separated from the base material 71.

[0023] A box-shaped pedestal 78 made of an insulating material and having a step on its inside is fixed on the bottom plate 16 of the lower chamber 17, and the substrate mounting table 70 is placed on the step of the pedestal 78.

[0024] An electrostatic chuck 76 on which a substrate G is directly placed is formed on an upper surface 71a of the base material 71. The electrostatic chuck 76 has a ceramic layer 74 (ceramic spray coating) which is a dielectric coating formed by spraying ceramics such as alumina or yttria, and a conductive layer 75 (electrostatic adsorption electrode) which is embedded inside the ceramic layer 74, has an electrostatic adsorption function, and is formed of tungsten, molybdenum, or the like.

[0025] The conductive layer 75 is connected to a DC power supply 85 via a power supply line 84. When a switch (not shown) on the power supply line 84 is turned on by the control unit 90, a DC voltage is applied from the DC power supply 85 to the conductive layer 75, generating a Coulomb force. Due to this Coulomb force, the substrate G is electrostatically attracted to the upper surface of the electrostatic chuck 76, and is held in a state in which it is placed on the upper surface 71a of the base material 71.

[0026] A temperature control medium flow path 72a that snakes so as to cover the entire area of ​​a rectangular plane is provided on a base material 71 that constitutes the substrate mounting table 70. Both ends of the temperature control medium flow path 72a are connected to a feed pipe 72b through which a temperature control medium is supplied to the temperature control medium flow path 72a and a return pipe 72c through which the temperature control medium that has been heated by flowing through the temperature control medium flow path 72a is discharged.

[0027] As shown in FIG. 1, the feed pipe 72b and the return pipe 72c are connected to a feed flow path 87 and a return flow path 88, respectively, and the feed flow path 87 and the return flow path 88 are connected to a chiller 86. The chiller 86 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). A refrigerant is used as the temperature control medium, and Galden (registered trademark) or Fluorinert (registered trademark) is used as the refrigerant. The illustrated temperature control form is a form in which the temperature control medium is circulated through the base material 71, but the base material 71 may have a built-in heater or the like and the temperature may be controlled by the heater, or the temperature may be controlled by both the temperature control medium and the heater. Instead of a heater, a high-temperature temperature control medium may be circulated to control the temperature with heating. Furthermore, a water channel or a heater may be provided in a temperature control plate that is a separate part separated from the base material 71. The heater, which is a resistor, is made of tungsten or molybdenum, or a compound of any one of these metals with alumina, titanium, etc. In the illustrated example, the base material 71 has a temperature control medium flow path 72a formed therein.

[0028] A temperature sensor (not shown) such as a thermocouple is provided on the base material 71, and monitor information from the temperature sensor is transmitted to the control unit 90 as needed. Then, based on the transmitted monitor information, the control unit 90 performs temperature control of the base material 71 and the substrate G. More specifically, the control unit 90 adjusts the temperature and flow rate of the temperature control medium supplied from the chiller 86 to the feed flow path 87. Then, the temperature control medium whose temperature and flow rate have been adjusted is circulated through the temperature control medium flow path 72a, thereby performing temperature control of the substrate mounting table 70. The temperature sensor such as a thermocouple may be provided in, for example, the electrostatic chuck 76.

[0029] A step is formed by the outer periphery of electrostatic chuck 76 and base material 71 and the upper surface of pedestal 78, and a rectangular frame-shaped focus ring 79 is placed on this step. With focus ring 79 placed on the step, the upper surface of focus ring 79 is set to be lower than the upper surface of electrostatic chuck 76. Focus ring 79 is made of ceramics such as alumina, quartz, or the like.

[0030] A power supply member 80 is connected to the lower surface of the base material 71. A power supply line 81 is connected to the lower end of the power supply member 80, and the power supply line 81 is connected to a high-frequency power supply 83, which is a bias power supply, via a matcher 82 that performs impedance matching. By applying high-frequency power of, for example, 3.2 MHz from the high-frequency power supply 83 to the substrate mounting table 70, an RF bias is generated, and ions generated by the high-frequency power supply 56, which is a source for generating plasma described below, are attracted to the substrate G, so that, for example, a film formation process can be performed on the substrate G. In this way, the substrate mounting table 70 forms a bias electrode that mounts the substrate G and generates an RF bias. At this time, a portion that is at ground potential inside the lower chamber 17 functions as an opposing electrode of the bias electrode and forms a return circuit for the high-frequency power. The metal window 30 may be configured as a part of the return circuit for the high-frequency power. The metal window 30 is formed by a plurality of divided metal windows 31. The number of divided metal windows 31 that form the metal window 30 can be set to various numbers, such as 12 or 24.

[0031] The divided metal window 31 has a conductor plate 32 and a shower plate 34. The divided metal window 31 also serves as a processing gas discharge section for discharging processing gas into the processing chamber S. Both the conductor plate 32 and the shower plate 34 are made of aluminum, an aluminum alloy, stainless steel, or the like, which is a non-magnetic, conductive, and corrosion-resistant metal or a metal that has been subjected to a corrosion-resistant surface treatment. The corrosion-resistant surface treatment is, for example, anodizing or ceramic spraying. In addition, the exposed surface 34a of the shower plate 34 facing the processing chamber S may be subjected to a plasma-resistant coating by anodizing or ceramic spraying. The conductor plate 32 is grounded via a ground wire (not shown), and the shower plate 34 is also grounded via the conductor plates 32 that are joined to each other.

[0032] Each divided metal window 31 constituting the metal window 30 is suspended from the top plate 12 of the upper chamber 13 by a plurality of suspenders (not shown). A spacer (not shown) made of an insulating material is disposed above each divided metal window 31, and a high-frequency antenna (inductively coupled antenna) 51 is disposed at a distance from the conductor plate 32 by the spacer. The high-frequency antenna 51 contributes to plasma generation and is formed by winding an antenna wire made of a metal with good electrical conductivity such as copper in a circular or spiral shape. For example, multiple circular antenna wires may be disposed. The high-frequency antenna 51 is disposed on the upper surface of the divided metal window 31, and is therefore suspended from the top plate 12 via the divided metal window 31. The high-frequency antenna 51 is disposed in the antenna chamber A of the upper chamber 13 at the top of the processing vessel 20.

[0033] Gas diffusion grooves 33 are formed on the lower surface of the conductor plate 32, and through holes 32b are provided to connect the gas diffusion grooves 33 to the upper end surface 32a. Gas introduction pipes 52 are embedded in the through holes 32b. A plurality of gas discharge holes 35 are formed in the shower plate 34, which communicate with the gas diffusion grooves 33 of the conductor plate 32 and the processing chamber S. The shower plate 34 is fastened to the lower surface of the conductor plate 32 in an area outside the gas diffusion grooves 33 by metal screws (not shown). The gas diffusion grooves may be formed on the upper surface of the shower plate.

[0034] Each divided metal window 31 is electrically insulated from the support frame 14 and the adjacent divided metal window 31 by an insulating member 37. Here, the insulating member 37 is made of a fluororesin such as PTFE (Polytetrafluoroethylene). An end face 37a of the insulating member 37 facing the processing chamber S is flush with an exposed face 34a of the shower plate 34 facing the processing chamber S, and an insulating cover member 38 is disposed straddling the exposed face 34a of the adjacent shower plate 34 while covering the end face 37a of the insulating member 37. This cover member 38 is made of ceramics such as alumina.

[0035] The insulating member 37 is made of a resin such as PTFE, which has high insulating performance and is lightweight. However, the plasma resistance of resin is not as high as that of ceramics such as alumina. Furthermore, it is difficult to perform plasma-resistant coating on the surface of the resin by anodizing or ceramic spraying. Therefore, in the plasma processing apparatus 100, the end surface 37a of the insulating member 37 on the processing chamber S side is covered with a cover member 38 made of ceramics, for example, to protect the insulating member 37 from plasma. Each insulating member 37, which insulates the support frame 14 and the divided metal window 31, and the adjacent divided metal windows 31 from each other, is covered with the cover member 38.

[0036] A power supply member 53 extending above the upper chamber 13 is connected to the high-frequency antenna 51, and a power supply line 54 is connected to the upper end of the power supply member 53. The power supply line 54 is connected to a high-frequency power source 56 via a matching box 55 that performs impedance matching.

[0037] When a high frequency power of, for example, 13.56 MHz is applied to the high frequency antenna 51 from the high frequency power supply 56, an inductive electric field is formed in the lower chamber 17. Due to this inductive electric field, the processing gas supplied from the shower plate 34 to the processing chamber S is converted into plasma, generating inductively coupled plasma.

[0038] The high frequency power supply 56 is a source for generating plasma, and the high frequency power supply 83 connected to the substrate mounting table 70 is a bias source that attracts the generated ions and imparts kinetic energy to them. In this way, the ion source generates plasma using inductive coupling, and a bias source, which is a separate power supply, is connected to the substrate mounting table 70 to control the ion energy, so that plasma generation and ion energy control are performed independently, thereby increasing the degree of freedom in the process.

[0039] 1, the gas introduction pipes 52 of each divided metal window 31 are gathered together in one place inside the antenna chamber A, and the gas introduction pipes 52 extending upward pass airtight through the supply port 12a opened in the top plate 12 of the upper chamber 13. The gas introduction pipes 52 are connected to a process gas supply source 64 via a gas supply pipe 61 that is airtightly joined thereto.

[0040] An opening / closing valve 62 and a flow rate controller 63 such as a mass flow controller are provided in the gas supply pipe 61. A processing gas supply unit 60 is formed by the gas supply pipe 61, the opening / closing valve 62, the flow rate controller 63, and a processing gas supply source 64. The gas supply pipe 61 branches in the middle, and each branch pipe is connected to an opening / closing valve, a flow rate controller, a processing gas supply source appropriate for the type of processing gas, and a cleaning gas supply source (not shown).

[0041] In plasma processing, a processing gas is supplied from a processing gas supply unit 60 through a gas supply pipe 61 and a gas introduction pipe 52 to the gas diffusion grooves 33 of the conductor plate 32 of each divided metal window 31. Then, the processing gas is discharged from each gas diffusion groove 33 through the gas discharge holes 35 of each shower plate 34 into the processing chamber S.

[0042] Thus, the plasma processing apparatus 100 includes a first plasma generating unit that generates processing plasma for performing substrate processing (film formation processing, etching processing, etc.) on the substrate G. The first plasma generating unit includes at least a metal window 30 and a high-frequency antenna 51. A high-frequency power source 56 supplies high-frequency power to the high-frequency antenna 51, and a processing gas supply unit 60 supplies processing gas to the processing chamber S through the divided metal window 31 (processing gas discharge unit). The first plasma generating unit forms an induction electric field in the processing chamber S, and generates plasma of the processing gas supplied into the processing chamber S by this induction electric field.

[0043] The remote plasma generator 200 is connected to the sidewall 15 of the processing vessel 20 via the conductive passage 210. The remote plasma generator 200 includes a second plasma generating unit (not shown). The remote plasma generator 200 converts a cleaning gas containing fluorine (F) supplied from a cleaning gas supply source 220 into plasma in the second plasma generating unit to generate cleaning species (e.g., active species such as ions and radicals of the cleaning gas). The remote plasma generator 200 is configured to introduce the cleaning species into the processing vessel 20 from the sidewall 15 of the processing vessel 20 via the conductive passage 210.

[0044] Note that, similarly to the processing gas, a cleaning gas supplied from a cleaning gas supply source into the processing chamber S via the gas supply pipe 61 and the shower plate 34 may be converted into plasma by an induction electric field formed in the lower chamber 17 by high-frequency power applied from a high-frequency power supply 56 to the high-frequency antenna 51, thereby generating plasma of the cleaning gas in the processing chamber S. In this configuration, the remote plasma generator 200 may be omitted. The plasma of the cleaning gas generated in the processing chamber S cleans the inside of the lower chamber 17 of the processing vessel 20.

[0045] The control unit 90 controls the operation of each component of the plasma processing apparatus 100, such as the chiller 86, the high frequency power supplies 56 and 83, the processing gas supply unit 60, and the exhaust unit 300 based on monitor information transmitted from a pressure gauge. 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 of ​​the RAM or ROM. The recipe sets control information for the plasma processing apparatus 100 with respect to process conditions. The control information includes, for example, the gas flow rate, the pressure in the processing vessel 20, the temperature in the processing vessel 20, the temperature of the substrate 71, and the process time.

[0046] 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, etc. The recipe and the like may be stored in a portable computer-readable storage medium such as a CD-ROM, a DVD, a memory card, etc., and set in the control unit 90 and read out. The control unit 90 also has user interfaces such as input devices 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 plasma processing apparatus 100, and an output device such as a printer.

[0047] An example of the operation of the plasma processing apparatus 100 will now be described with reference to Fig. 2. Fig. 2 is a flow chart showing an example of the operation of the plasma processing apparatus 100, for processing one substrate.

[0048] In step S101, the substrate G is subjected to substrate processing. Here, the substrate G is carried into the processing vessel 20 and placed on the substrate placement table 70. Next, the control unit 90 carries out the substrate processing on the substrate G using plasma of the processing gas supplied to the processing chamber S. Here, the substrate processing is a film formation process using a plasma CVD method. The processing gas includes, for example, SiH4 gas. The temperature of the substrate placement table 70 during the substrate processing is within a range of 200°C to 260°C (for example, 250°C). If the film is formed at a temperature lower than 200°C, the characteristics of the final device will deteriorate, so the film needs to be formed at a temperature of 200°C or higher, but if the temperature becomes too high, the device will be damaged. Therefore, it is conventionally appropriate to carry out the film formation process at a temperature of 200°C to 260°C. Then, the substrate G is carried out from the processing vessel 20. During the substrate processing, reaction by-products are deposited in the processing chamber S of the processing vessel 20, for example, on the inner wall of the lower chamber 17.

[0049] In step S102, it is determined whether or not to perform a cleaning process. If the cleaning process is to be performed (S102: YES), the process of the control unit 90 proceeds to step S103. If the cleaning process is not to be performed (S102: NO), the flowchart ends. If there is a next substrate G, the control unit 90 may perform the substrate process of step S101 on the next substrate G, and repeat the flowchart of FIG. 2.

[0050] In step S103, a cleaning process is performed on the processing vessel 20. The cleaning process is a process for removing reaction by-products deposited in the processing chamber S of the processing vessel 20. The control unit 90 cleans the inside of the processing vessel 20 by using plasma of a cleaning gas supplied to the processing chamber S. Here, the cleaning gas is a cleaning gas containing fluorine (F). Specifically, the cleaning gas is NF3 gas.

[0051] Here, the substrate mounting table 70 is required to have heat resistance capable of withstanding high temperatures during substrate processing, and corrosion resistance during cleaning processing.

[0052] The substrate mounting table 70 according to this embodiment will be further described with reference to Fig. 3. Fig. 3 is a schematic cross-sectional view showing an example of the substrate mounting table 70 according to this embodiment.

[0053] The substrate 71 is made of martensitic stainless steel. The surface of the substrate 71 is coated with a nickel-containing plating layer 710. The nickel-containing plating may be, for example, pure nickel, or may be nickel-phosphorus alloy plating containing phosphorus in addition to nickel. Nickel alloys containing other components may also be used. The nickel-containing plating layer 710 has corrosion resistance against NF3 gas used as a cleaning gas. The substrate 71 is also formed with a substrate through hole 711 communicating with the sprayed coating through hole 761 penetrating the ceramic layer 74, a countersunk hole 712 for inserting a bolt for fixing the substrate mounting table 70, and a screw hole (not shown). The nickel-containing plating layer 710 is also formed on the inner wall surfaces of the substrate through hole 711 and the countersunk hole 712. The substrate through hole 711 includes a heat transfer gas supply hole that supplies a heat transfer gas between the back surface of the substrate G and the mounting surface of the substrate mounting table 70, and a lift pin through hole in which a lift pin (not shown) that raises and lowers the substrate G is positioned.

[0054] The upper surface 71a of the base material 71 has a ceramic layer 74, which is a ceramic spray coating. The ceramic layer 74 is made of, for example, alumina (Al2O3). The conductive layer 75 is embedded inside the ceramic layer 74. The conductive layer 75 is made of, for example, tungsten (W).

[0055] Next, the substrate mounting table 70C according to the reference example will be further described with reference to Fig. 4. Fig. 4 is a schematic cross-sectional view showing an example of the substrate mounting table 70C according to the reference example.

[0056] The base material 71 is made of martensitic stainless steel. On the other hand, the nickel-containing plating layer 710 is not provided on the surface of the base material 71.

[0057] The substrate 71 has a ceramic layer 74, which is a ceramic spray coating, on its upper surface 71a. The ceramic layer 74 is made of alumina, for example. The conductive layer 75 is embedded inside the ceramic layer 74.

[0058] In both the substrate mounting tables 70 and 70C, the base material 71 is made of martensitic stainless steel, thereby making it possible to reduce the difference in thermal expansion between the base material 71 and the ceramic layer 74 made of alumina. This makes it possible to prevent the ceramic layer 74 from peeling off from the base material 71 due to the difference in thermal expansion. In other words, the heat resistance of the substrate mounting tables 70 and 70C during substrate processing can be improved.

[0059] Meanwhile, during the cleaning process, fluorine (F) reaches the surface of the substrate 71 through the substrate through-hole 711 and the countersunk hole 712. In addition, fluorine (F) that has permeated the ceramic layer 74 also reaches the boundary surface (bonding surface) between the substrate 71 and the ceramic layer 74.

[0060] 4, a corroded portion 715 is generated on the surface of the base material 71. Furthermore, the occurrence of the corroded portion 715 on the interface between the base material 71 and the ceramic layer 74 may cause the ceramic layer 74 to peel off from the base material 71. The peeling of the ceramic layer 74 may cause an insulation failure of the electrostatic chuck 76.

[0061] 3, the nickel-containing plating layer 710 of the substrate supporting table 70 according to the present embodiment can prevent corrosion of the substrate 71. That is, the substrate supporting table 70 according to the present embodiment has corrosion resistance against the cleaning gas. This can prevent the ceramic layer 74 from peeling off from the substrate 71.

[0062] In addition, it is preferable that the substrate 71 having the nickel-containing plating layer 710 is subjected to a blasting treatment at the interface where the substrate 71 is bonded to the ceramic layer 74. This can improve the adhesion to the ceramic layer 74 formed by thermal spraying.

[0063] The substrate mounting table 70 according to this embodiment and the substrate mounting table 70C according to a reference example will be further described with reference to FIGS.

[0064] Fig. 5 is a graph showing a structure created to simulate the substrate mounting table 70 according to this embodiment and the composition ratio of this structure after cleaning. Fig. 5(a) shows a structure created to simulate the substrate mounting table 70 shown in Fig. 3. That is, a nickel-containing plating layer 710 was formed on the surface of a base material 71 made of martensitic stainless steel, the boundary surface was blasted, and a ceramic layer 74 was sprayed thereon.

[0065] In FIG. 5(b), a test was performed in which the prepared structure was exposed to plasma of an F-containing gas to simulate a cleaning process, and the atomic concentration was detected at an analysis position P1 near the interface between the ceramic layer 74 and the nickel-containing plating layer 710 (substrate 71).

[0066] Fig. 6 is a graph showing a structure created to simulate the substrate support 70C according to the reference example and the composition ratio of the structure after cleaning. Fig. 6(a) shows a structure created to simulate the substrate support 70C shown in Fig. 4. That is, a ceramic layer 74 was sprayed onto a base material 71 made of martensitic stainless steel.

[0067] In FIG. 6(b), a test was performed in which the fabricated structure was exposed to plasma of an F-containing gas to simulate a cleaning process, and the atomic concentration was detected at an analysis position P2 near the interface between the ceramic layer 74 and the substrate 71.

[0068] 6(b), fluorine (F) was detected at analysis position P2 near the boundary surface. This indicates that fluorine (F) entered the structure from the side as a result of the ceramic layer 74 peeling off from the substrate 71.

[0069] 5(b), fluorine (F) is not detected at the analysis position P1 near the interface, which indicates that the ceramic layer 74 is not peeled off from the substrate 71.

[0070] As shown by comparing FIG. 5(b) and FIG. 6(b), the substrate mounting table 70 according to this embodiment has heat resistance in substrate processing and corrosion resistance in cleaning processing.

[0071] Next, the heat resistance (heat resistance temperature) and corrosion resistance (resistance to high-temperature F radicals) will be further described with reference to Fig. 7. Fig. 7 is an example of a diagram showing the heat resistance temperature and the availability of resistance to high-temperature F radicals.

[0072] In (a), a substrate 71 is made of aluminum, a ceramic layer 74 (ceramic spray coating) is made of alumina (Al2O3), and a conductive layer 75 (electrostatic attraction electrode) is made of tungsten (W).

[0073] In (b), the substrate 71 is made of austenitic stainless steel, the ceramic layer 74 (ceramic spray coating) is made of alumina (Al2O3), and the conductive layer 75 (electrostatic attraction electrode) is made of tungsten (W).

[0074] In (c), the base material 71 is made of martensitic stainless steel, the ceramic layer 74 (ceramic spray coating) is made of alumina (Al2O3), and the conductive layer 75 (electrostatic attraction electrode) is made of tungsten (W), which corresponds to the substrate mounting table 70C according to the reference example shown in FIG.

[0075] In (d), the base material 71 is made of martensitic stainless steel having a nickel-containing plating layer 710 on its surface, the ceramic layer 74 (ceramic spray coating) is made of alumina (Al2O3), and the conductive layer 75 (electrostatic attraction electrode) is made of tungsten (W). That is, it corresponds to the substrate mounting table 70 according to this embodiment shown in FIG.

[0076] The substrate mounting tables shown in (a) to (d) were heated at an evaluation temperature to evaluate whether or not damage to the substrate mounting table (such as dielectric breakdown due to cracks in the ceramic layer 74) occurred. The heat-resistant temperature range of each substrate mounting table is indicated by an arrow.

[0077] Further, the substrate mounting tables shown in (a) to (d) were evaluated for corrosion resistance caused by the plasma of the cleaning gas, that is, for resistance to high-temperature F radicals.

[0078] The aluminum substrate stage shown in (a) is resistant to corrosion by the plasma of the cleaning gas. In other words, it has good resistance to high-temperature F radicals (OK). However, damage to the substrate stage was confirmed at evaluation temperatures of 130°C or higher.

[0079] The substrate stage made of austenitic stainless steel shown in (b) is corroded by the plasma of the cleaning gas. In other words, it is not resistant to high-temperature F radicals. Moreover, damage to the substrate stage was confirmed at evaluation temperatures of 160°C or higher.

[0080] The substrate stage made of martensitic stainless steel shown in (c) is corroded by the plasma of the cleaning gas. In other words, it is not resistant to high-temperature F radicals. Moreover, damage to the substrate stage was confirmed at evaluation temperatures of 340°C or higher.

[0081] The substrate stage made of martensitic stainless steel with a nickel-containing plating layer on the surface shown in (d) has corrosion resistance against the plasma of the cleaning gas. In other words, the resistance to high-temperature F radicals is good (OK). In addition, damage to the substrate stage was confirmed at evaluation temperatures of 280°C or higher.

[0082] Thus, the substrate support table 70 according to this embodiment can achieve both heat resistance in substrate processing and corrosion resistance in cleaning processing. That is, by forming the base 71 from martensitic stainless steel, the difference in thermal expansion between the base 71 and alumina (Al2O3) constituting the ceramic layer 74 can be reduced compared to when the base 71 is formed from aluminum or austenitic stainless steel. This suppresses cracking of the ceramic layer 74 and improves the heat resistance of the substrate support table 70. In addition, by covering the surface of the martensitic stainless steel with a nickel-containing plating layer, the corrosion resistance against the plasma of the cleaning gas is improved. [Explanation of symbols]

[0083] 64 Process gas supply source 70 Board mounting stand 71 Base material 71a Top side 74 Ceramic layer (ceramic spray coating) 75 Conductive layer (electrostatic adhesion electrode) 76 Electrostatic Chuck 100 Plasma processing apparatus (substrate processing system) 220 Cleaning gas supply source 711 Base material through hole 761 Thermal spray coating penetration hole

Claims

1. 1. A substrate processing system capable of performing a substrate processing on a substrate by plasma of a processing gas inside a processing vessel and performing a cleaning processing on the processing vessel by plasma of a cleaning gas, comprising: a process gas supply source connected to the process vessel and supplying the process gas; a cleaning gas supply source connected to the processing vessel and supplying the cleaning gas; a plasma generating unit capable of generating plasma of the processing gas or plasma of the cleaning gas; a substrate placement stage provided within the processing chamber and configured to place the substrate thereon; A control unit that controls at least the substrate processing and the cleaning processing, The substrate mounting table is A base material having a surface covered with a nickel-containing plating layer and a mounting surface on which the substrate is mounted; a ceramic thermal spray coating formed on the nickel-containing plating layer on the mounting surface of the substrate; an electrostatic attraction electrode embedded inside the ceramic spray coating; the cleaning gas is a fluorine-containing gas; The substrate is made of martensitic stainless steel, The control unit controls the substrate processing to be performed at a temperature of 200° C. or higher and 260° C. or lower. Substrate processing system.

2. The fluorine-containing gas is NF ３ It is a gas, The substrate processing system of claim 1 .

3. The process gas contains at least SiH ４ Including gas, The substrate processing system of claim 2 .

4. the substrate has a substrate through-hole that opens onto the mounting surface and communicates with a thermal spray coating through-hole that penetrates the ceramic thermal spray coating, The nickel-containing plating layer is also applied to the inner surface of the substrate through hole. The substrate processing system of claim 1 .

5. A cleaning method for performing a cleaning process using plasma of a cleaning gas in a processing vessel for accommodating a substrate therein and performing a substrate processing using plasma of a processing gas in a substrate processing system, comprising: The substrate processing system includes: a process gas supply source connected to the process vessel and supplying the process gas; a cleaning gas supply source connected to the processing vessel and supplying the cleaning gas; a plasma generating unit capable of generating plasma of the processing gas or plasma of the cleaning gas; a substrate mounting table provided inside the processing chamber and configured to mount the substrate thereon; The substrate mounting table is A base material having a surface covered with a nickel-containing plating layer and a mounting surface on which the substrate is mounted; a ceramic thermal spray coating formed on the nickel-containing plating layer on the mounting surface of the substrate; an electrostatic attraction electrode embedded inside the ceramic spray coating; the cleaning gas is a fluorine-containing gas; The substrate is made of martensitic stainless steel, After the substrate processing is performed at 200° C. or more and 260° C. or less and the substrate is unloaded from the processing chamber, a plasma generating unit configured to generate plasma of the cleaning gas by supplying the cleaning gas to the processing vessel, and cleaning an inside of the processing vessel with the plasma of the cleaning gas.

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