Substrate processing system and processing container cleaning method

Abstract

The invention provides a substrate processing system and a processing container cleaning method. The substrate processing system includes: a processing gas supply source connected to a processing container and supplying a processing gas; a cleaning gas supply source that is connected to the processing container and supplies a cleaning gas; a plasma generation unit capable of generating plasma of a processing gas or a cleaning gas; a substrate mounting table which is provided inside the processing container and on which a substrate is mounted; and a control unit that controls at least the substrate processing and the cleaning processing, the substrate mounting table being provided with: a base material having a surface covered with a nickel-containing plating layer, the base material having a mounting surface on which the substrate is mounted; a ceramic thermal spray film formed on the nickel-containing plating layer on the placement surface of the base material; the cleaning gas is a fluorine-containing gas, the base material is made of martensitic stainless steel, and the control unit performs control so as to perform substrate treatment at 200 DEG C or more and 260 DEG C or less.

Description

Technical Field

[0001] The present disclosure relates to a substrate processing system and a processing container cleaning method. Background Art

[0002] Patent Document 1 discloses that a static holding disk is formed by ceramic thermal spraying using martensitic stainless steel as a base material.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-147278 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] In one aspect, the present disclosure provides a substrate processing system and a processing container cleaning method having heat resistance and corrosion resistance.

[0008] Solutions for solving problems

[0009] In order to solve the above-mentioned problems, according to one embodiment, a substrate processing system is provided, wherein the substrate processing system can perform substrate processing on a substrate inside a processing container using plasma of a processing gas, and perform cleaning processing on the processing container using plasma of a cleaning gas, and the substrate processing system comprises: a processing gas supply source connected to the processing container and supplying the processing gas to the processing container; a cleaning gas supply source connected to the processing container and supplying the cleaning gas to the processing container; and a plasma generating unit capable of generating plasma of the processing gas or plasma of the cleaning gas. sub-body; a substrate mounting table, which is provided inside the processing container and is used to mount the substrate; and a control unit, which controls at least the substrate processing and the cleaning processing, wherein the substrate mounting table comprises: a substrate, a surface of which is covered with a nickel-containing plating layer, and the substrate has a mounting surface for mounting the substrate; a ceramic sprayed film, which is formed on the nickel-containing plating layer at the mounting surface of the substrate; and an electrostatic adsorption electrode, which is buried in the interior of the ceramic sprayed film, the cleaning gas is a fluorine-containing gas, the substrate is composed of martensitic stainless steel, and the control unit controls to perform the substrate processing at a temperature above 200°C and below 260°C.

[0010] Effects of the Invention

[0011] According to one aspect, the present disclosure can provide a substrate processing system and a processing container cleaning method having heat resistance and corrosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a diagram showing an example of a processing system according to an embodiment.

[0013] Figure 2 This is a flowchart showing an example of the operation of the plasma processing apparatus.

[0014] Figure 3 This is a schematic cross-sectional view showing an example of a substrate mounting table according to the present embodiment.

[0015] Figure 4 It is a schematic cross-sectional view showing an example of a substrate mounting table according to a reference example.

[0016] Figure 5 This is a graph showing a structure produced by simulating the substrate mounting table according to the present embodiment and a composition ratio after the structure is cleaned.

[0017] Figure 6 This is a graph showing a structure produced by simulating a substrate mounting table according to a reference example and a composition ratio after the structure is cleaned.

[0018] Figure 7 This is an example of a graph showing the heat resistance temperature and whether or not the heat resistance to high temperature F radicals is possible. DETAILED DESCRIPTION

[0019] Hereinafter, the mode for implementing the present disclosure will be described with reference to the drawings. In each of the drawings, the same components are denoted by the same reference numerals, and duplicate descriptions may be omitted.

[0020] [Plasma processing device]

[0021] use Figure 1 The plasma processing apparatus 100 (substrate processing system) will be described. Figure 1 1 is a longitudinal cross-sectional view showing an example of the plasma processing apparatus 100 .

[0022] Figure 1The plasma processing device 100 shown is an inductively coupled plasma (ICP) processing device that performs various substrate processing methods on a substrate G (hereinafter simply referred to as a "substrate") that is rectangular when viewed from above and is used for a flat panel display (Flat Panel Display, hereinafter referred to as "FPD"). As the material of the substrate, glass is mainly used, and transparent synthetic resins are sometimes used depending on the application. Here, the substrate processing includes film forming processing, etching processing, etc. using a CVD (Chemical Vapor Deposition) method. As FPD, a liquid crystal display (LCD), electroluminescence (EL), a plasma display panel (PDP), etc. can be exemplified. The substrate includes a supporting substrate in addition to a substrate having a circuit patterned on the surface. In addition, the plane size of the FPD substrate has been increasing with each generation, and the plane size of the substrate G processed by the plasma processing apparatus 100 ranges from about 1500 mm×1800 mm in the 6th generation to about 3000 mm×3400 mm in the 10.5th generation, for example. In addition, the thickness of the substrate G is about 0.2 mm to several mm.

[0023] Figure 1 The plasma processing apparatus 100 shown in the figure comprises: a processing container 20 having a rectangular parallelepiped box shape; a substrate mounting table (mounting table) 70, which is arranged in the processing container 20 to mount the substrate G and has a rectangular outer shape in a plan view; and a control unit 90. In addition, the processing container may also be a cylindrical box shape, an elliptical cylindrical box shape, etc. In this embodiment, the substrate mounting table is also circular or elliptical, and the substrate mounted on the substrate mounting table is also circular.

[0024] The processing container 20 is divided into two spaces, upper and lower, by the metal window 30. The antenna room A as the upper space is formed by the upper chamber 13, and the processing chamber S as the lower space is formed by the lower chamber 17. In the processing container 20, a rectangular ring-shaped support frame 14 is provided at a position that becomes a boundary between the upper chamber 13 and the lower chamber 17 so as to protrude toward the inner side of the processing container 20, and the metal window 30 is mounted on the support frame 14.

[0025] The upper chamber 13 forming the antenna chamber A is formed of the side wall 11 and the top plate 12 and is formed of metal such as aluminum or aluminum alloy as a whole.

[0026] The lower chamber 17 having the processing chamber S therein is formed of a side wall 15 and a bottom plate 16 , and is formed entirely of a metal such as aluminum or an aluminum alloy. The side wall 15 is grounded via a grounding wire 21 .

[0027] The support frame 14 is formed of conductive metal such as aluminum or aluminum alloy, and can also be called a metal frame.

[0028] A rectangular annular (without joint) sealing groove 22 is formed at the upper end of the side wall 15 of the lower chamber 17, and a sealing component 23 such as an O-ring is embedded in the sealing groove 22. The abutting surface of the support frame 14 holds the sealing component 23, thereby forming a sealing structure between the lower chamber 17 and the support frame 14.

[0029] A loading / unloading port 15a for loading / unloading the substrate G in and out of the lower chamber 17 is provided on 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. The lower chamber 17 is adjacent to a transfer chamber (not shown) containing a transfer mechanism, and the gate valve 24 is controlled to open and close so that the substrate G is loaded and unloaded through the loading / unloading port 15a by the transfer mechanism.

[0030] In addition, a plurality of exhaust ports 16a are provided on the bottom plate 16 of the lower chamber 17. The side wall 15 of the processing container 20 that accommodates the substrate stage 70 in the lower chamber 17 is formed into a polygonal cylindrical shape. In other words, the horizontal cross-section of the processing container 20 at least at the position of the lower chamber 17 that accommodates the substrate stage 70 is formed into a rectangular shape. In addition, the substrate stage 70 is formed into a rectangular shape when viewed from above. In other words, the horizontal cross-section of the substrate stage 70 is formed into a rectangular shape. The plurality of exhaust ports 16a are arranged on the bottom plate 16 of the processing container 20 in a manner that surrounds the substrate stage 70. In other words, the exhaust ports 16a are arranged at a position that is outside the substrate stage 70 and inside the side wall 15 of the processing container 20 (lower chamber 17) when viewed from above.

[0031] Each exhaust port 16a is connected to an exhaust device 300. In addition, a pressure gauge (not shown) is provided at an appropriate position of the lower chamber 17, and monitoring information of the pressure gauge is transmitted to the control unit 90.

[0032] The substrate mounting table 70 includes a base material 71 and an electrostatic holding plate (holding plate: chuck) 76 formed on an upper surface 71 a of the base material 71 .

[0033] The substrate 71 is rectangular in plan view and has a planar dimension equal to that of the substrate G placed on the substrate mounting table 70. The length of the long side of the substrate 71 can be set to about 1800 mm to 3400 mm, and the length of the short side can be set to about 1500 mm to 3000 mm. With respect to this planar dimension, the thickness of the substrate 71 can be, for example, about 50 mm to 100 mm.

[0034] The temperature control medium flow path 72a is provided on the base material 71 so as to meander to cover the entire area of ​​the rectangular plane. Alternatively, the temperature control medium flow path may be provided on a temperature control plate which is another member separated from the base material 71.

[0035] A box-shaped pedestal 78 is fixed to the bottom plate 16 of the lower chamber 17 . The pedestal 78 is formed of an insulating material and has a step portion inside. The substrate mounting table 70 is mounted on the step portion of the pedestal 78 .

[0036] An electrostatic holding disk 76 for directly placing the substrate G is formed on the upper surface 71a of the base material 71. The electrostatic holding disk 76 has a ceramic layer 74 (ceramic sprayed film) which is a dielectric coating formed by spraying ceramics such as aluminum oxide and yttrium oxide, and a conductive layer 75 (electrostatic adsorption electrode) formed of tungsten, molybdenum, etc. The conductive layer 75 is buried in the ceramic layer 74 and has an electrostatic adsorption function.

[0037] The conductive layer 75 is connected to a DC power source 85 via a power supply line 84. When a switch (not shown) provided on the power supply line 84 is turned on by the control unit 90, a DC voltage is applied from the DC power source 85 to the conductive layer 75, thereby generating a Coulomb force. The Coulomb force electrostatically adsorbs the substrate G to the upper surface of the electrostatic holding disk 76, and holds the substrate G in a state of being placed on the upper surface 71a of the base material 71.

[0038] A temperature control medium flow path 72a is provided on a base material 71 constituting the substrate mounting table 70. A feeding pipe 72b for supplying a temperature control medium to the temperature control medium flow path 72a and a return pipe 72c for discharging the temperature control medium after flowing through the temperature control medium flow path 72a and increasing its temperature are connected to both ends of the temperature control medium flow path 72a.

[0039] like Figure 1As shown, the feed pipe 72b and the return pipe 72c are connected to the feed flow path 87 and the return flow path 88 respectively, and the feed flow path 87 and the return flow path 88 are connected to the cooler 86. The cooler 86 has a main body for controlling the temperature of the temperature control medium and the ejection flow rate, and a pump for pressurizing and conveying the temperature control medium (both are not shown). In addition, as the temperature control medium, a refrigerant is applied, and the refrigerant is Galden (registered trademark) (perfluoropolyether), Fluorinert (registered trademark) (electronic fluorinated liquid), etc. The temperature control method of the example in the figure is a method of circulating the temperature control medium to the substrate 71, but it can also be a method of temperature control by a heater built into the substrate 71, or it can be a method of temperature control by both the temperature control medium and the heater. In addition, it can also be a method of temperature control accompanied by heating by circulating a high-temperature temperature control medium to replace the heater. In addition, a water path and a heater can also be set on the temperature control plate as other components separated from the substrate 71. The heater as a resistor is formed of tungsten, molybdenum, or a compound of any of these metals and aluminum oxide, titanium, etc. In the example shown in the figure, a temperature control medium flow path 72 a is formed in the base material 71 .

[0040] A temperature sensor such as a thermocouple (not shown) is provided on the substrate 71, and monitoring information of the temperature sensor is sent to the control unit 90 at any time. Then, based on the sent monitoring information, the control unit 90 performs temperature control of the substrate 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 cooler 86 to the feed flow path 87. Then, the temperature control medium after temperature adjustment and flow adjustment is circulated to the temperature control medium flow path 72a, thereby performing temperature control of the substrate mounting table 70. In addition, a temperature sensor such as a thermocouple may be provided on the electrostatic holding disk 76, for example.

[0041] A step portion is formed by the outer periphery of the electrostatic holding disk 76 and the substrate 71, and the upper surface of the pedestal 78, and a rectangular frame-shaped focus ring 79 is placed on the step portion. When the focus ring 79 is placed on the step portion, the upper surface of the focus ring 79 is set lower than the upper surface of the electrostatic holding disk 76. The focus ring 79 is made of ceramics such as alumina or quartz.

[0042] A power supply member 80 is connected to the lower surface of the substrate 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 as a bias power supply via a matching device 82 for impedance matching. By applying a high-frequency power of, for example, 3.2 MHz to the substrate mounting table 70 from the high-frequency power supply 83 to generate an RF bias, ions generated by the high-frequency power supply 56 as a source power supply for plasma generation described below are attracted to the substrate G, and, for example, a film forming process can be performed on the substrate G. In this way, the substrate mounting table 70 forms a bias electrode for mounting the substrate G and generating an RF bias. At this time, the portion of the lower chamber 17 that becomes the ground potential functions as an opposite electrode of the bias electrode, forming a return circuit for the high-frequency power. In addition, the metal window 30 can also 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 forming the metal window 30 can be set to a variety of numbers such as twelve and twenty-four.

[0043] 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 ejection portion for ejecting a processing gas into the interior of the processing chamber S. Both the conductor plate 32 and the shower plate 34 are formed of a non-magnetic, conductive, and corrosion-resistant metal or a metal subjected to a corrosion-resistant surface treatment, such as aluminum, an aluminum alloy, or stainless steel. The corrosion-resistant surface treatment is, for example, an anodizing treatment, ceramic spraying, or the like. In addition, a plasma-resistant coating based on an anodizing treatment or ceramic spraying may be applied to the exposed surface 34a of the shower plate 34 facing the processing chamber S. The conductor plate 32 is grounded via a grounding wire (not shown), and the shower plate 34 is also grounded via the conductor plates 32 joined to each other.

[0044] Each divided metal window 31 constituting the metal window 30 is suspended from the ceiling 12 of the upper chamber 13 by a plurality of suspension rods (not shown). An insulator (not shown) formed by an insulating member is provided above each divided metal window 31, and a high-frequency antenna (inductive coupling antenna) 51 is provided through the insulator in a manner separated from the conductor plate 32. The high-frequency antenna 51 contributes to the generation of plasma, and is formed by winding an antenna wire formed by a metal with good conductivity such as copper into a ring or spiral shape. For example, multiple ring-shaped antenna wires can be provided. The high-frequency antenna 51 is provided on the upper surface of the divided metal window 31, and is therefore suspended from the ceiling 12 via the divided metal window 31. The high-frequency antenna 51 is provided in the upper part of the processing container 20, the antenna room A of the upper chamber 13.

[0045] A gas diffusion groove 33 is formed on the lower surface of the conductor plate 32, and a through hole 32b is provided to connect the gas diffusion groove 33 with the upper end surface 32a. A gas introduction pipe 52 is buried in the through hole 32b. A plurality of gas ejection holes 35 are provided in the shower plate 34 to connect the gas diffusion groove 33 of the conductor plate 32 and the processing chamber S. The shower plate 34 is fastened to the lower surface of the area outside the gas diffusion groove 33 of the conductor plate 32 by a metal screw member (not shown). In addition, the gas diffusion groove may also be provided on the upper surface of the shower plate.

[0046] Each divided metal window 31 is electrically insulated from the support frame 14 and adjacent divided metal windows 31 by an insulating member 37. Here, the insulating member 37 is formed of a fluororesin such as PTFE (Polytetrafluoroethylene). The end face 37a of the insulating member 37 facing the processing chamber S is coplanar with the exposed surface 34a of the shower plate 34 facing the processing chamber S, and an insulating cover member 38 is arranged in a manner covering the end face 37a of the insulating member 37 and spanning the exposed surface 34a of the adjacent shower plate 34. The cover member 38 is formed of ceramics such as alumina.

[0047] The insulating member 37 is formed of a resin such as PTFE which has high insulating performance and is lightweight, but the plasma resistance of the resin is not high compared to ceramics such as alumina. In addition, it is difficult to perform plasma-resistant coating on the surface of the resin by anodizing or ceramic spraying. Therefore, in the plasma processing device 100, the insulating member 37 is protected from the influence of plasma by covering the end face 37a of the insulating member 37 on the side of the processing chamber S with a cover member 38 made of, for example, ceramic. The insulating members 37 that insulate the support frame 14 from the split metal window 31 and the adjacent split metal windows 31 from each other are covered by the cover member 38.

[0048] A power supply member 53 extending upward from the upper chamber 13 is connected to the high frequency antenna 51 . 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 device 55 for impedance matching.

[0049] 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, thereby forming an induced electric field in the lower chamber 17. The induced electric field converts the processing gas supplied from the shower plate 34 to the processing chamber S into plasma to generate inductively coupled plasma, and ions in the plasma are supplied to the substrate G.

[0050] The high frequency power supply 56 is a source power supply for generating plasma, and the high frequency power supply 83 connected to the substrate mounting table 70 is a bias power supply for attracting the generated ions to give the ions kinetic energy. By using the ion source power supply to generate plasma using inductive coupling, and connecting the bias power supply as another power supply to the substrate mounting table 70 to control the ion energy, the plasma generation and the ion energy control can be performed independently, thereby improving the degree of freedom of the process.

[0051] like Figure 1 As shown, the gas introduction pipes 52 of the divided metal windows 31 are gathered at one place in the antenna chamber A, and the gas introduction pipes 52 extending upward are airtightly penetrated through the supply port 12a opened in the ceiling 12 of the upper chamber 13. Moreover, the gas introduction pipes 52 are connected to the processing gas supply source 64 via the gas supply pipe 61 that is airtightly connected.

[0052] An on-off valve 62 and a flow controller 63 such as a mass flow controller are provided at a midway position of the gas supply pipe 61. The gas supply pipe 61, the on-off valve 62, the flow controller 63 and the process gas supply source 64 form a process gas supply unit 60. In addition, the gas supply pipe 61 is branched midway, and each branch pipe is connected to an on-off valve and a flow controller, a process gas supply source corresponding to the type of process gas, and a cleaning gas supply source (not shown).

[0053] During the plasma processing, the processing gas supplied from the processing gas supply unit 60 is supplied to the gas diffusion grooves 33 of the conductor plate 32 of each divided metal window 31 via the gas supply pipe 61 and the gas introduction pipe 52. Then, the gas is ejected from each gas diffusion groove 33 into the processing chamber S via each gas ejection hole 35 of the shower plate 34.

[0054] As described above, the plasma processing apparatus 100 includes a first plasma generating unit for generating a processing plasma to perform substrate processing (film forming 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 supply 56 supplies high-frequency power to the high-frequency antenna 51, and a processing gas supply unit 60 supplies a processing gas to the processing chamber S via the divided metal window 31 (processing gas ejection unit). The first plasma generating unit forms an induced electric field in the processing chamber S, and generates plasma of the processing gas supplied to the processing chamber S through the induced electric field.

[0055] The remote plasma generating device 200 is connected to the side wall 15 of the processing container 20 via the guide passage 210. The remote plasma generating device 200 includes a second plasma generating unit (not shown). The remote plasma generating device 200 converts the cleaning gas containing fluorine (F) supplied from the cleaning gas supply source 220 into plasma through the second plasma generating unit to generate cleaning species (for example, active species such as ions and radicals of the cleaning gas). In addition, the remote plasma generating device 200 is configured to introduce the cleaning species from the side wall 15 of the processing container 20 into the processing container 20 via the guide passage 210.

[0056] In addition, a structure may be adopted in which, similarly to the process gas, the cleaning gas supplied from the cleaning gas supply source to the process chamber S via the gas supply pipe 61 and the shower plate 34 is converted into plasma by the induced electric field formed in the lower chamber 17 by the high frequency power applied from the high frequency power source 56 to the high frequency antenna 51, thereby generating plasma of the cleaning gas in the process chamber S. In the case of this structure, the remote plasma generating device 200 may be omitted. The plasma of the cleaning gas generated in the process chamber S cleans the interior of the lower chamber 17 of the process container 20.

[0057] The control unit 90 controls various components of the plasma processing apparatus 100, such as the cooler 86, the high frequency power supplies 56, 83, and the processing gas supply unit 60, and controls the operation of the exhaust device 300 based on the monitoring information sent from the 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 performs a predetermined process according to a process (process recipe) stored in a storage area of ​​the RAM and ROM. Control information of the plasma processing apparatus 100 relative to the process conditions is set in the process. The control information includes, for example, a gas flow rate, a pressure in the processing container 20, a temperature in the processing container 20, a temperature of the substrate 71, a process time, and the like.

[0058] The process and the program used by the control unit 90 may be stored in a hard disk, an optical disk, a magneto-optical disk, etc. In addition, the process 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. In addition, the control unit 90 has a user interface such as an input device such as a keyboard and a mouse for inputting commands, a display device such as a display that visually displays the operating status of the plasma processing device 100, and an output device such as a printer.

[0059] Here, use Figure 2 An example of the operation of the plasma processing apparatus 100 will be described. Figure 2 This is a flowchart showing an example of the operation of the plasma processing apparatus 100 and a process for one substrate.

[0060] In step S101, substrate processing is performed on substrate G. Here, substrate G is carried into processing container 20 and mounted on substrate stage 70. Next, control unit 90 performs substrate processing on substrate G using plasma of processing gas supplied to processing chamber S. Here, substrate processing is film forming processing using plasma CVD method. Processing gas includes SiH4 gas, for example. In addition, the temperature of substrate stage 70 during substrate processing is in the range of 200°C to 260°C (for example, 250°C). When film forming is performed at a temperature lower than 200°C, the characteristics of the final device deteriorate, so film forming needs to be performed at a temperature higher than 200°C, but when the temperature becomes too high, the device will be damaged. Therefore, it is appropriate to perform film forming processing at a temperature higher than 200°C and lower than 260°C in practice. Then, substrate G is carried out from processing container 20. In addition, during substrate processing, reaction byproducts are deposited in processing chamber S of processing container 20, for example, on the inner wall of lower chamber 17.

[0061] In step S102, it is determined whether to perform the cleaning process. In the case of performing the cleaning process (S102: "Yes"), the control unit 90 proceeds to step S103. In the case of not performing the cleaning process (S102: "No"), the flowchart ends. Alternatively, if there is a next substrate G, the control unit 90 performs the substrate process of step 101 on the next substrate G, and repeats the process. Figure 2 Flowchart of the process.

[0062] In step S103, a cleaning process is performed on the processing container 20. The cleaning process is a process for removing reaction byproducts deposited in the processing chamber S of the processing container 20. The control unit 90 uses the plasma of the cleaning gas supplied to the processing chamber S to clean the inside of the processing container 20. Here, the cleaning gas is a cleaning gas containing fluorine (F). Specifically, the cleaning gas is NF3 gas.

[0063] Here, the substrate mounting table 70 is required to have heat resistance capable of coping with high temperatures during substrate processing and corrosion resistance during cleaning processing.

[0064] use Figure 3 The substrate mounting table 70 according to the present embodiment will be further described. Figure 3 It is a schematic cross-sectional view showing an example of the substrate mounting table 70 according to the present embodiment.

[0065] The substrate 71 is made of martensitic stainless steel. The surface of the substrate 71 is covered with a nickel-containing plating 710. The nickel-containing plating may be, for example, pure nickel, or may be a nickel-phosphorus alloy plating containing phosphorus in addition to nickel. In addition, a nickel alloy containing other components may also be used. The nickel-containing plating 710 is corrosion-resistant to NF3 gas used as a cleaning gas. In addition, a substrate through hole 711 connected to the sprayed film through hole 761 penetrating the ceramic layer 74, a countersunk hole 712 for inserting a bolt for fixing the substrate mounting table 70, a threaded hole (not shown), etc. are formed in the substrate 71. The nickel-containing plating 710 is also applied to the inner wall surface of the substrate through hole 711 and the countersunk hole 712. In addition, the substrate through hole 711 includes a heat transfer gas supply hole for supplying a heat transfer gas between the back side of the substrate G and the mounting surface of the substrate mounting table 70, a lifting pin through hole for arranging a lifting pin (not shown) for lifting the substrate G, etc.

[0066] The upper surface 71a of the substrate 71 has a ceramic layer 74 as a ceramic sprayed film. The ceramic layer 74 is made of, for example, aluminum oxide (Al2O3). The conductive layer 75 is embedded in the ceramic layer 74. The conductive layer 75 is made of, for example, tungsten (W).

[0067] Next, use Figure 4 The substrate mounting table 70C according to the reference example will be further described. Figure 4 It is a schematic cross-sectional view showing an example of a substrate mounting table 70C according to a reference example.

[0068] The substrate 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 substrate 71 .

[0069] The base material 71 has a ceramic layer 74 as a ceramic sprayed film on the upper surface 71 a. The ceramic layer 74 is made of, for example, alumina. The conductive layer 75 is buried inside the ceramic layer 74.

[0070] Here, in both the substrate stage 70 and the substrate stage 70C, the base material 71 is made of martensitic stainless steel, thereby reducing the thermal expansion difference with the ceramic layer 74 made of alumina. As a result, it is possible to prevent the ceramic layer 74 from peeling off from the base material 71 due to the thermal expansion difference. That is, the heat resistance of the substrate stage 70, 70C during substrate processing can be improved.

[0071] Meanwhile, during the cleaning process, fluorine (F) reaches the surface of the substrate 71 from the substrate through-holes 711 and the countersunk holes 712. Furthermore, the fluorine (F) that has passed through the ceramic layer 74 also reaches the boundary surface (joining surface) between the substrate 71 and the ceramic layer 74.

[0072] Therefore, in Figure 4In the substrate mounting table 70C according to the reference example shown, a corrosion portion 715 is generated on the surface of the base material 71. In addition, since the corrosion portion 715 is generated on the boundary surface between the base material 71 and the ceramic layer 74, the ceramic layer 74 may be peeled off from the base material 71. Since the ceramic layer 74 is peeled off, insulation failure of the electrostatic holding disk 76 may occur.

[0073] In contrast, Figure 3 In the substrate mounting table 70 according to the present embodiment shown, the nickel-containing plating layer 710 can prevent corrosion of the base material 71. That is, the substrate mounting table 70 according to the present embodiment has corrosion resistance to the cleaning gas. Thus, the ceramic layer 74 can be prevented from peeling off from the base material 71.

[0074] In addition, it is preferable to perform sandblasting on the interface between the base material 71 having the nickel-containing plating layer 710 and the ceramic layer 74. This can improve the adhesion between the base material 71 and the ceramic layer 74 formed by thermal spraying.

[0075] use Figure 5 and Figure 6 The substrate mounting table 70 according to the present embodiment and the substrate mounting table 70C according to the reference example will be further described.

[0076] Figure 5 It is a graph showing a structure produced by simulating the substrate mounting table 70 according to the present embodiment and a composition ratio after the structure is cleaned. Figure 5 (a) is a simulation Figure 3 The structure of the substrate mounting table 70 shown in the figure is that a nickel-containing plating layer 710 is formed on the surface of a base material 71 made of martensitic stainless steel, a boundary surface is subjected to sandblasting, and a ceramic layer 74 is sprayed on the surface.

[0077] exist Figure 5 In (b), the fabricated structure was subjected to a simulated cleaning process to expose the structure to a plasma containing F gas, and the atomic number concentration at an analysis position P1 near the boundary surface between the ceramic layer 74 and the nickel-containing plating layer 710 (substrate 71) was detected.

[0078] Figure 6 : is a graph showing a structure produced by simulating the substrate mounting table 70C according to the reference example, and a composition ratio after the structure is cleaned. Figure 6 (a) is a simulation Figure 4 The substrate mounting table 70C shown is a structure in which a ceramic layer 74 is thermally sprayed on a base material 71 made of martensitic stainless steel.

[0079] exist Figure 6In (b), the fabricated structure was subjected to a simulated cleaning process to expose the structure to a plasma containing a F-containing gas, and the atomic number concentration at an analysis position P2 near the boundary surface between the ceramic layer 74 and the substrate 71 was measured.

[0080] like Figure 6 As shown in (b), fluorine (F) was detected at the analysis position P2 near the boundary surface. This indicates that fluorine (F) entered from the side of the structure due to the peeling of the ceramic layer 74 from the substrate 71.

[0081] In contrast, Figure 5 As shown in (b), fluorine (F) was not detected at the analysis position P1 near the boundary surface. That is, it means that the ceramic layer 74 was not peeled off from the substrate 71.

[0082] If Figure 5 (b) and Figure 6 As shown in the comparison of (b), the substrate mounting table 70 according to the present embodiment has heat resistance in substrate processing and corrosion resistance in cleaning processing.

[0083] Next, use Figure 7 To further illustrate the heat resistance (heat resistance temperature) and corrosion resistance (resistance to high temperature F radicals). Figure 7 This is an example of a graph showing the heat resistance temperature and whether or not the heat resistance to high temperature F radicals is possible.

[0084] In (a), the substrate 71 is made of aluminum, the ceramic layer 74 (ceramic sprayed film) is made of aluminum oxide (Al 2 O 3 ), and the conductive layer 75 (electrostatic adsorption electrode) is made of tungsten (W).

[0085] In (b), the substrate 71 is made of austenitic stainless steel, the ceramic layer 74 (ceramic sprayed film) is made of aluminum oxide (Al 2 O 3 ), and the conductive layer 75 (electrostatic adsorption electrode) is made of tungsten (W).

[0086] In (c), the substrate 71 is made of martensitic stainless steel, the ceramic layer 74 (ceramic spray film) is made of aluminum oxide (Al2O3), and the conductive layer 75 (electrostatic adsorption electrode) is made of tungsten (W). Figure 4 A substrate mounting table 70C according to a reference example is shown.

[0087] In (d), the substrate 71 is made of martensitic stainless steel having a nickel-containing plating layer 710 on the surface, the ceramic layer 74 (ceramic spray film) is made of aluminum oxide (Al2O3), and the conductive layer 75 (electrostatic adsorption electrode) is made of tungsten (W). Figure 3 The substrate mounting table 70 according to the present embodiment is shown.

[0088] The substrate stages shown in (a) to (d) were evaluated to see whether damage (such as insulation breakdown due to cracking of the ceramic layer 74) occurred when the substrate stages were heated at the evaluation temperature. The range of the heat-resistant temperature of each substrate stage is indicated by arrows.

[0089] In addition, the substrate mounting tables shown in (a) to (d) were evaluated for their corrosion resistance against plasma corrosion by a cleaning gas, that is, their resistance against high-temperature F radicals.

[0090] The substrate mounting table made of aluminum shown in (a) has corrosion resistance to the plasma of the cleaning gas. In other words, the resistance to high-temperature F radicals is good (OK). On the other hand, when the evaluation temperature is 130° C. or higher, damage to the substrate mounting table is confirmed.

[0091] The substrate mounting table made of austenitic stainless steel shown in (b) corrodes due to the plasma of the cleaning gas. That is, it is not resistant to high temperature F radicals (NG). In addition, damage to the substrate mounting table was confirmed when the evaluation temperature was 160°C or higher.

[0092] The substrate mounting table made of martensitic stainless steel shown in (c) corrodes due to the plasma of the cleaning gas. That is, it is not resistant to high temperature F radicals (NG). In addition, damage to the substrate mounting table was confirmed when the evaluation temperature was 340°C or higher.

[0093] The substrate mounting table shown in (d) is made of martensitic stainless steel having a nickel-containing plating layer on the surface and has corrosion resistance to the plasma of the cleaning gas. In other words, the resistance to high-temperature F radicals is good (OK). In addition, when the evaluation temperature is above 280°C, damage to the substrate mounting table is confirmed.

[0094] As described above, according to the substrate mounting table 70 involved in this embodiment, it is possible to achieve both heat resistance in substrate processing and corrosion resistance in cleaning processing. That is, compared with the case where the substrate 71 is composed of aluminum or austenitic stainless steel, by forming the substrate 71 of martensitic stainless steel, the thermal expansion difference between the substrate 71 and the aluminum oxide (Al2O3) constituting the ceramic layer 74 can be reduced. As a result, cracking of the ceramic layer 74 is suppressed, and the heat resistance of the substrate mounting table 70 is improved. In addition, by covering the surface of the martensitic stainless steel with a nickel-containing plating layer, the corrosion resistance to the plasma of the cleaning gas is improved.

[0095] Description of Reference Numerals

[0096] 64: processing gas supply source; 70: substrate mounting table; 71: substrate; 71a: upper surface; 74: ceramic layer (ceramic sprayed film); 75: conductive layer (electrostatic adsorption electrode); 76: electrostatic holding disk; 100: plasma processing device (substrate processing system); 220: cleaning gas supply source; 711: substrate through hole; 761: sprayed film through hole.

Claims

1. A substrate processing system capable of performing substrate processing on a substrate using plasma of a processing gas in a processing container and performing cleaning processing on the processing container using plasma of a cleaning gas, the substrate processing system comprising: a processing gas supply source connected to the processing container and supplying the processing gas to the processing container; a cleaning gas supply source connected to the processing container and supplying the cleaning gas to the processing container; a plasma generating unit capable of generating plasma of the processing gas or plasma of the cleaning gas; a substrate mounting table provided in the processing container and used for mounting the substrate; and a control unit that controls at least the substrate processing and the cleaning processing, in, The substrate mounting table comprises: A substrate, the surface of which is covered with a nickel-containing plating layer, the substrate having a mounting surface for mounting the substrate; a ceramic sprayed film formed on the nickel-containing plating layer at the mounting surface of the substrate; and The electrostatic adsorption electrode is embedded in the ceramic sprayed film. The cleaning gas is a fluorine-containing gas, The substrate is made of martensitic stainless steel. The control unit performs control so that the substrate processing is performed at a temperature of 200° C. or higher and 260° C. or lower.

2. The substrate processing system according to claim 1, wherein: The fluorine-containing gas is NF3 gas.

3. The substrate processing system according to claim 2, wherein: The processing gas at least includes SiH 4 gas.

4. The substrate processing system according to claim 1, wherein: The substrate has a substrate through-hole, the substrate through-hole opens on the mounting surface and communicates with a thermal spray film through-hole penetrating the ceramic thermal spray film. The nickel-containing plating layer is also applied to the inner surface of the substrate through-hole.

5. A method for cleaning a processing container, comprising: performing a cleaning process using plasma of a cleaning gas on a processing container that accommodates a substrate and performs a substrate process using plasma of a processing gas in a substrate processing system; The substrate processing system comprises: a processing gas supply source connected to the processing container and supplying the processing gas to the processing container; a cleaning gas supply source connected to the processing container and supplying the cleaning gas to the processing container; a plasma generating section capable of generating plasma of the processing gas or plasma of the cleaning gas; and a substrate mounting table provided inside the processing container and used for mounting the substrate; in, The substrate mounting table comprises: A substrate, the surface of which is covered with a nickel-containing plating layer, the substrate having a mounting surface for mounting the substrate; a ceramic sprayed film formed on the nickel-containing plating layer at the mounting surface of the substrate; and The electrostatic adsorption electrode is embedded in the ceramic sprayed film. The cleaning gas is a fluorine-containing gas, The substrate is made of martensitic stainless steel. After the substrate processing is performed at a temperature of 200° C. to 260° C. and the substrate is removed from the processing container, the cleaning gas is supplied to the processing container to generate plasma of the cleaning gas through the plasma generating unit, and the interior of the processing container is cleaned using the plasma of the cleaning gas.

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