JP2025014849A - Substrate mounting base, substrate processing device and substrate processing method - Google Patents

Abstract

To provide a substrate mounting base which is usable in a high-temperature process, and to provide a substrate processing device and a substrate processing method.SOLUTION: A substrate mounting base is installed inside of a processing container, in which processing is applied to a substrate, and the substrate is mounted thereon. The substrate mounting base comprises: an electrostatic chuck consisting of a base material including a dielectric layer with a built-in attraction electrode on a mounting surface on which the substrate is mounted; a heating plate consisting of aluminum or an aluminum alloy connected at a lower side of the electrostatic chuck; and a cooling plate consisting of the aluminum or the aluminum alloy connected at a lower side of the heating plate. A face of the heating plate corresponding to the cooling plate is defined as a first face, and a face of the cooling plate corresponding to the heating plate is defined as a second face. The substrate mounting base includes a gap space extending in a direction along the first face and the second face between the heating plate and the cooling plate and includes alumite coatings at least on any one of or both the first face exposed in the gap space and the second face exposed in the gap space.SELECTED DRAWING: Figure 2

Description

This disclosure relates to a substrate placement table, a substrate processing apparatus, and a substrate processing method.

Patent Document 1 describes a substrate holder that is composed of a heat exchange jacket through which a heat medium flows, a heat equalizing plate that reduces unevenness in the temperature distribution on the flat heat exchange surface of the heat exchange jacket, and an electrostatic chuck that has an adsorption electrode embedded in an insulating material, in which a carbon fluoride-based heat medium heated to about 170°C is transported to the heat exchange jacket, and the electrostatic chuck is uniformly heated via the heat equalizing plate.

Japanese Patent Application Publication No. 05-29300

In one aspect, the present disclosure provides a substrate mounting table, a substrate processing apparatus, and a substrate processing method that can be used for high-temperature processes.

In order to solve the above problem, according to one aspect, a substrate mounting table is provided that is installed inside a processing vessel that processes a substrate and that mounts the substrate thereon, the substrate mounting table having an electrostatic chuck made of a base material with a dielectric layer having an internal adsorption electrode on the mounting surface on which the substrate is mounted, a heating plate made of aluminum or an aluminum alloy connected below the electrostatic chuck, and a cooling plate made of aluminum or an aluminum alloy connected below the heating plate, the surface of the heating plate that corresponds to the cooling plate being a first surface, the surface of the cooling plate that corresponds to the heating plate being a second surface, a gap space extending in a direction along the first surface and the second surface is provided between the heating plate and the cooling plate, and at least one or both of the first surface exposed to the gap space and the second surface exposed to the gap space have an anodized aluminum coating.

According to one aspect, the present disclosure provides a substrate mounting table, a substrate processing apparatus, and a substrate processing method that can be used in high-temperature processes.

FIG. 1 is a vertical cross-sectional view showing an example of a plasma processing apparatus. 2 is a schematic cross-sectional view of an example of the substrate mounting table according to the first embodiment. 3 is an example of a partially enlarged schematic cross-sectional view of the substrate mounting table according to the first embodiment. 1 is an example of a table showing the relationship between anodizing and emissivity. 1 is a schematic cross-sectional view of a substrate mounting table according to a reference example. FIG. 11 is a schematic cross-sectional view of a substrate mounting table according to a second embodiment.

Below, a description will be given of a mode for carrying out the present disclosure with reference to the drawings. In each drawing, the same components are given the same reference numerals, and duplicate descriptions may be omitted.

[Plasma Processing Apparatus]
A plasma processing apparatus 100 (substrate processing apparatus) 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.

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. Here, the substrate processing includes film formation processing using a chemical vapor deposition (CVD) method, etching processing, etc. Examples of FPDs include liquid crystal displays (LCDs), electroluminescence (EL), plasma display panels (PDPs), etc. The substrate includes a form in which a circuit is patterned on its surface, as well as a support substrate. In addition, the planar dimensions of FPD substrates have become 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 approximately 1500 mm x 1800 mm for the sixth generation to approximately 3000 mm x 3400 mm for the 10.5th generation. The thickness of the substrate G is approximately 0.2 mm to several mm.

The plasma processing apparatus 100 shown in FIG. 1 has a processing vessel 20 having a rectangular box shape, a substrate mounting table (mounting table) 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 form, the substrate mounting table is also circular or elliptical, and the substrate mounted on the substrate mounting table is also circular, etc.

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

The upper chamber 13 that forms the antenna room A is formed by the side walls 11 and the top plate 12, and is made as a whole from a metal such as aluminum or an aluminum alloy.

The lower chamber 17, which contains the processing chamber S, 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 also grounded by a ground wire 21.

The support frame 14 is made of a metal such as conductive aluminum or an aluminum alloy, and can also be called a metal frame.

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

A loading/unloading port 15a is provided in the side wall 15 of the lower chamber 17 for loading and unloading the substrate G into and from 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.

The bottom plate 16 of the lower chamber 17 is provided with a plurality of exhaust ports 16a. The side wall 15 of the processing vessel 20 that houses the substrate mounting table 70 in the lower chamber 17 is formed in a square 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. The substrate mounting table 70 is formed in a rectangular horizontal cross section when viewed from above. 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 on 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.

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

The substrate mounting table 70 has an electrostatic chuck 71, a heating plate 72, and a cooling plate 73. The electrostatic chuck 71 has a mounting surface for holding the substrate G on its upper surface, and includes a base material 711, a dielectric layer 712, and an adsorption electrode 713.

The substrate 711 has a rectangular shape in plan view, and has planar dimensions similar to those of the substrate G placed on the substrate placement table 70. The length of the long side of the substrate 711 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 substrate 711 can be, for example, approximately 50 mm to 100 mm.

The heating plate 72 is disposed below the substrate 711 of the electrostatic chuck 71. The cooling plate 73 is disposed below the heating plate 72.

A box-shaped base 78 made of an insulating material and having a step on the 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 base 78.

The upper surface 711a of the substrate 711 has a dielectric layer 712 (e.g., a ceramic spray coating) which is a dielectric coating formed by spraying ceramics such as alumina or yttria, and an adsorption electrode 713 (conductive layer) which is embedded inside the dielectric layer 712, has an electrostatic adsorption function, and is formed of tungsten, molybdenum, or the like.

The adsorption electrode 713 is connected to a DC power source 85 via a power supply line 84. When the control unit 90 turns on a switch (not shown) on the power supply line 84, a DC voltage is applied from the DC power source 85 to the adsorption electrode 713, generating a Coulomb force. This Coulomb force electrostatically adsorbs the substrate G to the upper surface of the electrostatic chuck 71, and the substrate G is held in a state of being placed on the substrate upper surface 711a via the dielectric layer 712. The substrate upper surface 711a on the upper surface of the substrate 711 is the mounting surface on which the electrostatic chuck 71 places the substrate G, and is also the mounting surface on which the substrate mounting table 70 places the substrate G.

The cooling plate 73 constituting the substrate mounting table 70 is provided with a heat medium flow path 73a that is serpentine so as to cover the entire area of the rectangular plane. Both ends of the heat medium flow path 73a are connected to a feed pipe 73b through which the heat medium is supplied to the heat medium flow path 73a, and a return pipe 73c through which the heat medium that has been heated by flowing through the heat medium flow path 73a is discharged.

As shown in FIG. 1, the feed pipe 73b and the return pipe 73c 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 heat medium, and a pump that pressurizes the heat medium (neither is shown). A refrigerant is used as the heat medium, and examples of the refrigerant that can be used include Galden (registered trademark) and Fluorinert (registered trademark).

The heating plate 72 is also provided with a heating element 72a (see FIG. 2 described later). The heating element 72a is, for example, a resistor heater, and may be made of tungsten or molybdenum, or a compound of one of these metals with alumina, titanium, or the like.

A temperature sensor (not shown) such as a thermocouple is provided on the substrate 711, and monitor information from the temperature sensor is sent to the control unit 90 at any time. Then, based on the monitor information sent, the control unit 90 performs temperature control of the substrate 711 and the substrate G. More specifically, the control unit 90 adjusts the power supplied to the heating element 72a and the temperature and flow rate of the heat medium supplied from the chiller 86 to the feed flow path 87. Then, the heat generation amount of the heating element 72a is adjusted, and the heat medium whose temperature and flow rate have been adjusted is circulated through the heat medium flow path 73a, thereby performing temperature control of the substrate mounting table 70.

A step is formed by the outer periphery of the electrostatic chuck 71 and the upper surface of the pedestal 78, and a rectangular frame-shaped focus ring 79 is placed on this step. When the focus ring 79 is placed on the step, the upper surface of the focus ring 79 is set to be slightly lower than the upper surface of the electrostatic chuck 71. The focus ring 79 is made of ceramics such as alumina or quartz. Note that since the upper surface of the electrostatic chuck 71 is made slightly smaller than the substrate G, the peripheral portion of the substrate G protrudes slightly from the peripheral portion of the electrostatic chuck 71 and comes into contact with the inner edge of the focus ring 79, and is separated from the upper surface of the focus ring 79 to form a small gap.

A power supply member 80 is connected to the lower surface of the heating plate 72 through an opening penetrating from the lower surface to the upper surface of the cooling plate 73. The base material 711 of the electrostatic chuck 71, the heating plate 72, and the cooling plate 73 are provided so as to be electrically conductive. 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, through 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 source for plasma generation 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, the portion that becomes the ground potential inside the lower chamber 17 functions as an opposing electrode of the bias electrode and constitutes a return circuit of the high-frequency power. The metal window 30 may be configured as a part of the return circuit of the high-frequency power. The metal window 30 is formed by multiple 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.

The divided metal window 31 has a conductor plate 32 and a shower plate 34. The divided metal window 31 also serves as a process gas discharge section that discharges process gas into the inside of the process chamber S. Both the conductor plate 32 and the shower plate 34 are made of aluminum, aluminum alloy, stainless steel, or the like, which is a non-magnetic, conductive, and corrosion-resistant metal or a metal that has been treated with a corrosion-resistant surface treatment. Examples of the corrosion-resistant surface treatment include anodizing and ceramic spraying. In addition, the exposed surface 34a of the shower plate 34 facing the process chamber S may be treated with a plasma-resistant coating by anodizing or ceramic spraying.

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 the generation of plasma 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 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.

The lower surface of the conductor plate 32 is formed with a gas diffusion groove 33, and a through hole 32b is provided that connects the gas diffusion groove 33 to the upper surface 32a of the conductor plate. At least a part of the gas introduction pipe 52 is embedded in this through hole 32b. The shower plate 34 is provided with a plurality of gas discharge holes 35 that connect the gas diffusion groove 33 of the conductor plate 32 to the processing chamber S. The shower plate 34 is fastened to the lower surface of the outer region of the gas diffusion groove 33 of the conductor plate 32 with a metal screw (not shown). The gas diffusion groove may be opened on the upper surface of the shower plate. The shape of the recess that constitutes the gas diffusion groove 33 is not limited to a so-called elongated shape, and may be a recess that spreads in a planar shape. The shape of the recess is not limited as long as a space for diffusing gas is formed.

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). The end face 37a of the insulating member 37 facing the processing chamber S is flush with the exposed face 34a of the shower plate 34 facing the processing chamber S, and an insulating cover member 38 is disposed across 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.

The insulating member 37 is made of a resin such as PTFE, which has high insulating properties and is lightweight, but compared to ceramics such as alumina, the plasma resistance of the resin is not as high. 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 ceramic, for example, to protect the insulating member 37 from plasma. Each insulating member 37, which insulates the support frame 14 from the divided metal window 31 and between adjacent divided metal windows 31, is covered with a cover member 38.

The high-frequency antenna 51 is connected to a power supply member 53 that extends above the upper chamber 13, 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 matcher 55 that performs impedance matching.

When high-frequency power, for example 13.56 MHz, is applied to the high-frequency antenna 51 from the high-frequency power source 56, an induced electric field is formed in the lower chamber 17. This induced electric field converts the processing gas supplied to the processing chamber S from the shower plate 34 into plasma, generating inductively coupled plasma, and ions in the plasma are provided to the substrate G.

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. In this way, by using two high frequency power supplies to generate plasma and control ion energy, plasma generation and ion energy control are performed independently, increasing the flexibility of the process.

As shown in FIG. 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 through the supply port 12a opened in the top plate 12 of the upper chamber 13. The gas introduction pipes 52 are then connected to the process gas supply source 64 via the gas supply pipe 61 that is airtightly connected.

An on-off valve 62 and a flow rate controller 63 such as a mass flow controller are provided midway along the gas supply pipe 61. The gas supply pipe 61, on-off valve 62, flow rate controller 63, and process gas supply source 64 form a process gas supply section 60. The gas supply pipe 61 branches midway, and each branch is connected to an on-off valve, a flow rate controller, and a process gas supply source appropriate for the type of process gas (not shown).

In 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. The gas is then discharged from each gas diffusion groove 33 into the processing chamber S via the gas discharge holes 35 of each shower plate 34.

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

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 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 executes a predetermined process according to a recipe (process recipe) stored in the memory area of the RAM or ROM. The recipe contains control information for the plasma processing apparatus 100 with respect to the 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 711, and the process time.

The recipe and the program applied by the control unit 90 may be stored, for example, on a hard disk, a compact disk, a magneto-optical disk, etc. The recipe, etc. may be stored in a portable computer-readable storage medium such as a CD-ROM, DVD, or memory card 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 or mouse for inputting commands, a display device such as a display that visualizes and displays the operating status of the plasma processing device 100, and an output device such as a printer.

Here, the substrate mounting table 70 will be further described with reference to Figures 2 and 3. Figure 2 is an example of a schematic cross-sectional view of the substrate mounting table 70 according to the first embodiment.

The substrate mounting table 70 has an electrostatic chuck 71, a heating plate 72, and a cooling plate 73.

The electrostatic chuck 71 has a mounting surface that holds the substrate G on its upper surface, and includes a base material 711, a dielectric layer 712, and an adsorption electrode 713 (see FIG. 1; not shown in FIG. 2). The dielectric layer 712 is formed on the upper surface of the base material 711, and the adsorption electrode 713 is provided inside the dielectric layer 712. The dielectric layer 712 places and holds the substrate G on its upper surface.

The substrate 711 is conductive, and high-frequency power is applied from the power supply member 80 (see FIG. 1) through the heating plate 72. The substrate 711 is preferably made of a material that has a small thermal expansion difference with the dielectric layer 712 at the process temperature (e.g., 250°C). The substrate 711 is made of, for example, stainless steel. This reduces the thermal expansion difference between the substrate 711 and the dielectric layer 712, and prevents the dielectric layer 712 from peeling off from the substrate 711 due to the thermal expansion difference between the substrate 711 and the dielectric layer 712 in a high-temperature process (e.g., 250°C). In other words, the generation of contaminants such as particles due to fragments of the peeled dielectric layer 712, insulation breakdown, and abnormal discharge are prevented. The surface of the substrate 711 made of stainless steel is preferably covered with a Ni plating layer 714 to prevent the substrate 711 from corroding due to plasma, process gas, etc.

The heating plate 72 is preferably made of a material that is electrically conductive and has good thermal conductivity. The heating plate 72 is made of, for example, aluminum or an aluminum alloy. The heating plate 72 also has a heating element 72a inside. The heating element 72a generates heat when power is supplied from an external power source (not shown), and heats the heating plate 72. The upper surface of the heating plate 72 abuts against the lower surface of the base material 711, and the heating element 72a generates heat, which is transferred from the heating plate 72 to the electrostatic chuck 71, heating the substrate G placed on the electrostatic chuck 71. When the heat of the plasma generated in the processing chamber S enters the substrate G, it is transferred to the heating plate 72 via the electrostatic chuck 71.

The cooling plate 73 is preferably made of a material that is electrically conductive and has good thermal conductivity. The cooling plate 73 is made of, for example, aluminum or an aluminum alloy. The cooling plate 73 also has a heat medium flow path 73a inside. The heat medium that has been adjusted to a predetermined temperature (for example, 100°C) by the chiller 86 (see FIG. 1) is supplied to the heat medium flow path 73a via the feed pipe 73b. The heat medium discharged from the heat medium flow path 73a circulates to the chiller 86 (see FIG. 1) via the return pipe 73c.

Figure 3 is an example of a partially enlarged schematic cross-sectional view of the substrate mounting table 70 according to the first embodiment.

Here, a support member 74 is disposed between the heating plate 72 and the cooling plate 73. The heating plate 72 is supported by the cooling plate 73 via the support member 74. The support member 74 may be disposed, for example, by forming a recess on the upper surface of the cooling plate 73. The support member 74 is preferably made of a material that is conductive and has lower thermal conductivity than the heating plate 72 and the cooling plate 73. The support member 74 is, for example, made of stainless steel. The support members 74 are provided in a plurality of positions on the outer periphery of the heating plate 72 and the cooling plate 73, either continuously or spaced apart in the circumferential direction, so that the heating plate 72 and the cooling plate 73 do not come into direct contact with each other. On the other hand, in the portion where the heating plate 72 and the cooling plate 73 indirectly contact each other via the support member 74, the amount of heat transfer is reduced because the thermal conductivity of the support member 74 is low. This suppresses heat transfer between the heating plate 72 and the cooling plate 73 via the support member 74. As a result, the amount of heat transfer between the heating plate 72 and the cooling plate 73 can be kept small, while the cooling plate 73 can reliably support the heating plate 72.

A gap space 75 is formed between the cooling plate 73 and the heating plate 72. In addition, a seal member 76a (second seal member) is arranged between the cooling plate 73 and the heating plate 72 at the outer periphery surrounding the gap space 75. The inside of this gap space 75 is sealed from the processing chamber S by the seal member 76a. The cooling plate 73 and the heating plate 72 sandwich the seal member 76a, but do not come into direct contact. As with the support member 74, there is indirect contact via the seal member 76a. The seal member 76a may be arranged, for example, on the outside of the support member 74.

The gap space 75 may also be connected to the space below the cooling plate 73 (the space surrounded by the lower surface of the cooling plate 73, the inner surface of the base 78, and the upper surface of the bottom plate 16) through an opening in the cooling plate 73 through which the power supply member 80 (see FIG. 1) is inserted. A seal member (not shown) may also be disposed between the gap space 75 and the space below the cooling plate 73 to seal the gap space 75.

As shown in FIG. 3, the surface of the heating plate 72 that faces the cooling plate 73 is defined as a first surface S1. The surface of the cooling plate 73 that faces the heating plate 72 is defined as a second surface S2. Between the cooling plate 73 and the heating plate 72, there is a gap space 75 that extends in a direction along the first surface S1 and the second surface S2. The distance between the first surface S1 and the second surface S2 is 2 mm or more and 10 mm or less.

In FIG. 3, a case is described in which a recess is formed on the upper surface (second surface S2) of the cooling plate 73 to form a gap space 75 between the cooling plate 73 and the heating plate 72, but this is not limited to the above. A recess may be formed on the lower surface (first surface S1) of the heating plate 72 to form a gap space 75 between the cooling plate 73 and the heating plate 72. Also, a recess may be formed on both the upper surface (first surface S1) of the cooling plate 73 and the lower surface (second surface S2) of the heating plate 72 to form a gap space 75 between the cooling plate 73 and the heating plate 72.

The heating plate 72 has an anodized aluminum coating 721 on the first surface S1 exposed to the gap space 75. In other words, the heating plate 72 has an anodized aluminum coating 721 on at least the wall surface exposed to the gap space 75. As shown in Figures 2 and 3, the heating plate 72 may have an anodized aluminum coating 721 on the entire surface.

The cooling plate 73 is anodized on the second surface S2 exposed to the gap space 75, and has an anodized coating 731. In other words, the cooling plate 73 has an anodized coating 731 at least on the wall surface exposed to the gap space 75. As shown in Figures 2 and 3, the cooling plate 73 may have an anodized coating 731 on the entire surface.

The substrate mounting table 70 will be described taking as an example a case where an anodized aluminum coating is provided on both the first surface S1 of the heating plate 72 and the second surface S2 of the cooling plate 73, but is not limited to this. The substrate mounting table 70 may be configured such that an anodized aluminum coating is provided on at least one of the first surface S1 of the cooling plate 73 and the second surface of the heating plate 72.

The cooling plate 73 is supported by a pedestal 78. A seal member 76b is disposed between the cooling plate 73 and the pedestal 78. A seal member 76c is disposed between the pedestal 78 and the bottom plate 16. The space below the cooling plate 73 is sealed from the processing chamber S by the seal members 76b and 76c. The space below the cooling plate 73 may be connected to the outside of the processing vessel 20 and may be an atmospheric atmosphere.

The supply pipe 73b and the return pipe 73c through which the heat medium flows are provided with sealing members 77 (first sealing members) at various connections. That is, the sealing members 77 prevent the heat medium from leaking to the outside, and come into contact with the heat medium and are cooled to a temperature approximately equal to that of the heat medium.

The gap space 75 may be a vacuum atmosphere. The gap space 75 may be an air atmosphere. The gap space 75 may be filled with a heat transfer gas (e.g., He gas).

Here, an example of processing a substrate G using the plasma processing device 100 is described.

First, the substrate G is placed on the substrate placement table 70 and electrostatically adsorbed by the electrostatic chuck 71.

Next, a process of heating the electrostatic chuck 71 by the heating plate 72 is performed. Here, the control unit 90 controls a power source (not shown) that supplies power to the heating element 72a based on the detected temperature of a temperature sensor (not shown) such as a thermocouple provided on the substrate 711. As a result, the temperatures of the heating plate 72, the electrostatic chuck 71 including the substrate 711, and the substrate G placed on the electrostatic chuck 71 are each adjusted to a desired temperature (e.g., 250°C). Meanwhile, a heat medium at a temperature lower than the desired temperature (e.g., 100°C) flows through the heat medium flow path 73a of the cooling plate 73, and the temperature of the cooling plate 73 is also low (e.g., 100°C).

Next, a process of removing heat from the electrostatic chuck 71 by the cooling plate 73 through heat exchange via the gap space 75 is performed. Here, the control unit 90 controls the plasma processing device 100 to perform a film-forming plasma process on the substrate G. When performing plasma processing on the substrate G, plasma is generated in the processing chamber S, and heat from the plasma is input to the substrate G and the substrate mounting table 70. The heat from the plasma is transferred to the heating plate 72 via the substrate G and the electrostatic chuck 71. Meanwhile, the heating plate 72 itself also generates heat by the heating element 72a. The heat input from the plasma and the heat generated by the heating plate 72 are thermally radiated from the first surface S1 of the heating plate 72 to the gap space 75. Then, the radiated heat radiated from the heating plate 72 to the gap space 75 is thermally absorbed by the second surface S2 of the cooling plate 73. At this time, the anodized coating covering the first surface S1 and the second surface S2 has high thermal emissivity and absorptivity, as described later. That is, by forming the anodized aluminum film 721 on the first surface S1, heat is efficiently dissipated, and by forming the anodized aluminum film 731 on the second surface S2, heat is efficiently absorbed. Therefore, in the gap space 75, heat is efficiently transferred from the first surface S1 to the second surface S2 by thermal radiation. Then, in the cooling plate 73, the heat is dissipated to the heat medium flowing through the heat medium flow path 73a. In this way, the substrate G and the electrostatic chuck 71 are heat-extracted by the cooling plate 73 through heat exchange via the gap space 75.

In addition, a process is performed to adjust the temperature of the substrate G via the electrostatic chuck 71. Here, the control unit 90 controls a power source (not shown) that supplies power to the heating element 72a based on the temperature detected by a temperature sensor (not shown), such as a thermocouple, provided on the base material 711.

These processes control the temperature of the substrate G during substrate processing to the desired temperature.

In this way, the substrate mounting table 70 shown in Figures 2 and 3 allows the substrate G to be processed in a high-temperature process (e.g., 250°C). In addition, when plasma heat is input to the substrate G or the substrate mounting table 70, it can be dissipated to a heat medium.

The temperature of the heat medium flowing through the feed pipe 73b and the return pipe 73c can be set to a temperature (e.g., 100°C) lower than the temperature (e.g., 250°C) of the high-temperature process of the substrate G. This makes it possible to prevent the seal members 77 provided on the feed pipe 73b and the return pipe 73c from being deteriorated by heat.

Here, we will explain the thermal radiation and absorption by anodized aluminum coatings using Figure 4. Figure 4 is an example of a table showing the relationship between various anodizing treatments and emissivity.

In the table of Figure 4, in Nos. 1 to 15, various anodizing treatments were applied to an aluminum alloy (A5052) substrate. Some of the anodizing treatments in Nos. 1 to 15 are treatments that form anodizing by different methods. No. 16, the first comparative example, shows an untreated (before anodizing) aluminum alloy (A5052) substrate. In Nos. 17 to 19, the second to fourth comparative examples, the aluminum alloy (A5052) substrate shown in No. 16 was blasted to change the surface roughness (substrate surface finish). For Nos. 1 to 19, the substrate surface finish (arithmetic mean roughness Ra), treatment, thickness of the anodizing film, substrate temperature at the time of emissivity measurement, and emissivity are shown.

As shown in Figure 4, the emissivity of the untreated base material shown in No. 16 is 0.38. In contrast, the various anodizing treatments and film thicknesses shown in Nos. 1 to 15 have high emissivity values close to 1. In other words, by providing an anodizing film on the surface of the base material, the emissivity is improved.

Here, in the various anodizing treatments shown in No. 1 to 15, the substrate surface finish (arithmetic mean roughness Ra) is greater than the untreated state shown in No. 16. In other words, the surface area is increased. For this reason, in No. 17 to 19, the substrate surface area was increased by blasting.

No increase in emissivity was observed with the various blasting treatments shown in Nos. 17 to 19.

As described above, regardless of the method of anodizing, providing an anodized aluminum coating on the surface of the base material improves the emissivity. That is, providing an anodized aluminum coating 721 on the surface of the heating plate 72 can increase the amount of radiated heat from the heating plate 72 to the gap space 75. Generally, the higher the thermal emissivity, the higher the thermal absorption rate, so an increase in thermal radiation also indicates an increase in heat absorption. Therefore, the absorption of radiated heat from the gap space 75 to the cooling plate 73 can also be increased.

This allows the plasma heat to be efficiently transferred from the heating plate 72 to the cooling plate 73 through the gap space 75.

Here, we will explain the substrate mounting table 70C according to the reference example. Figure 5 is an example of a schematic cross-sectional view of the substrate mounting table 70C according to the reference example.

The substrate mounting table 70C of the reference example does not include a heating plate 72, and a cooling plate 73 is provided directly below the base material 711.

Here, an example will be described in which the substrate G is processed in a high-temperature process (e.g., 250°C) on the substrate mounting table 70C according to the reference example. A high-temperature heat medium (e.g., 250°C) is circulated through the heat medium flow path 73a of the cooling plate 73. As a result, the seal members 77 and 76b are also exposed to high temperatures. As a result, there is a risk that the seal members 77 and 76b will deteriorate due to heat, resulting in effects such as increased frequency of replacement.

In contrast, in the substrate mounting table 70 shown in Figures 2 and 3, even when the substrate G is processed in a high-temperature process (e.g., 250°C), a heat medium at a temperature lower than the desired process temperature (e.g., 100°C) flows through the heat medium flow path 73a of the cooling plate 73, and the cooling plate 73 can be maintained at a low temperature. This makes it possible to prevent the sealing member 77 and the sealing member 76b from being deteriorated by heat, etc.

Figure 6 is an example of a schematic cross-sectional view of the substrate mounting table 70A according to the second embodiment.

6, the substrate mounting table 70A includes a gas passage 89a communicating with the gap space 75, on-off valves 89b1 and 89b2 provided in the gas passage 89a, a pressure sensor 89c provided in the gas passage 89a for detecting the pressure of the gap space 75, a gas supply source 89d1, and an exhaust device 89d2. Although not shown in FIG. 6, a seal member (not shown) is arranged around the opening (see FIG. 1) of the cooling plate 73 through which the power supply member 80 is inserted, and the gap space 75 and the space below the cooling plate 73 are sealed. As a result, the gap space 75 is formed such that the upper surface is partitioned by the first surface S1, the lower surface is partitioned by the second surface S2, the outer periphery side is partitioned by the seal member 76a, and the inner periphery side is partitioned by the seal member (not shown).

By opening the on-off valve 89b1, gas is filled from the gas supply source 89d1 through the gas passage 89a into the gap space 75. The gas filled into the gap space 75 may be the atmosphere or a heat transfer gas (e.g., He gas, Ar gas, etc.). In addition, by opening the on-off valve 89b2, the gas in the gap space 75 is exhausted by the exhaust device 89d2 through the gas passage 89a.

In this way, the substrate mounting table 70A can control the pressure (filling amount) of the gas in the gap space 75. It can also control the pressure (filling amount) of the heat transfer gas in the gap space 75. This makes it possible to control heat transfer by thermal convection via the heat transfer gas. That is, in addition to heat transfer by radiation, it is possible to control the amount of heat transfer from the heating plate 72 to the cooling plate 73 by the heat transfer gas.

Here, an example of processing a substrate G using a plasma processing apparatus 100 including a substrate mounting table 70A according to the second embodiment will be described.

First, a process is performed in which the gap space 75 is filled with air or a heat transfer gas. That is, the heat transfer characteristics between the heating plate 72 and the cooling plate 73 are adjusted. This makes it possible to adjust the heat transfer characteristics between the heating plate 72 and the cooling plate 73 according to, for example, the substrate processing process. Also, in a substrate processing system including multiple plasma processing apparatuses 100, it is possible to adjust the machine difference in the heat transfer characteristics between the heating plate 72 and the cooling plate 73.

The plasma processing apparatus 100 has been described above, but the present disclosure is not limited to the above-described embodiment, and various modifications and improvements are possible within the scope of the gist of the present disclosure described in the claims. In addition, although a film formation process has been described as a substrate process, the present invention is not limited to this, and can also be applied to etching processes, ashing processes, and other processes in which the substrate placement table becomes hot.

G substrate 20 processing vessel 70 substrate placement table 71 electrostatic chuck 711 substrate 711a substrate upper surface 712 dielectric layer 713 attraction electrode 714 Ni plating layer 72 heating plate 72a heating element 721 alumite coating 73 cooling plate 73a heat medium flow path 73b feed pipe 73c return pipe 731 alumite coating 74 support member 75 gap spaces 76a to 76c, 77 seal member 78 pedestal 79 focus ring 89a gas passage 89b1 on-off valve 89b2 on-off valve 89c pressure sensor 89d1 gas supply source 89d2 exhaust device S1 first surface S2 second surface 90 control unit 100 plasma processing apparatus

Claims (12)

A substrate mounting table is installed in a processing chamber for processing a substrate, the substrate being mounted on the substrate mounting table, the substrate mounting table comprising:
The substrate mounting table is
an electrostatic chuck including a base material having a dielectric layer with an adsorption electrode built in on a mounting surface on which the substrate is mounted;
a heating plate made of aluminum or an aluminum alloy and connected below the electrostatic chuck;
a cooling plate made of aluminum or an aluminum alloy and connected below the heating plate;
a surface of the heating plate corresponding to the cooling plate is defined as a first surface;
a surface of the cooling plate corresponding to the heating plate is a second surface;
a gap space extending in a direction along the first surface and the second surface is provided between the heating plate and the cooling plate,
At least one or both of the first surface exposed to the gap space and the second surface exposed to the gap space have an anodized aluminum coating.
Substrate placement stand. In the gap space, the distance between the first surface and the second surface is 2 mm or more and 10 mm or less.
The substrate mounting table according to claim 1 . the heating plate having a heating element;
The cooling plate has a heat medium flow path through which a heat medium flows.
The substrate mounting table according to claim 1 . A first seal member is disposed in a feed pipe and a return pipe connected to the heat medium flow path.
The substrate mounting table according to claim 3 . The heating plate is supported on the cooling plate via a support member.
The substrate mounting table according to claim 1 . A second seal member is disposed between the heating plate and the cooling plate surrounding the gap space.
The substrate mounting table according to claim 1 . The gap space is filled with air or a heat transfer gas.
The substrate mounting table according to claim 6 . A substrate processing apparatus for processing a substrate,
a processing vessel in which the substrate is processed;
a substrate placement stage disposed inside the processing chamber and configured to place the substrate thereon;
The substrate mounting table is
an electrostatic chuck including a base material having a dielectric layer with an adsorption electrode built in on a mounting surface on which the substrate is mounted;
a heating plate made of aluminum or an aluminum alloy and connected below the electrostatic chuck;
a cooling plate made of aluminum or an aluminum alloy and connected below the heating plate;
a surface of the heating plate corresponding to the cooling plate is defined as a first surface;
a surface of the cooling plate corresponding to the heating plate is a second surface;
a gap space extending in a direction along the first surface and the second surface is provided between the heating plate and the cooling plate,
At least one or both of the first surface exposed to the gap space and the second surface exposed to the gap space have an anodized aluminum coating.
Substrate processing equipment. the heating plate having a heating element;
The cooling plate has a heat medium flow path through which a heat medium flows,
A first seal member is disposed in a feed pipe and a return pipe connected to the heat medium flow path.
The substrate processing apparatus according to claim 8 . 1. A substrate processing method for processing a substrate inside a processing vessel, comprising:
a substrate placement stage for placing the substrate inside the processing vessel;
The substrate mounting table is
an electrostatic chuck including a base material having a dielectric layer with an adsorption electrode built in on a mounting surface on which the substrate is mounted;
a heating plate made of aluminum or an aluminum alloy and connected below the electrostatic chuck;
a cooling plate made of aluminum or an aluminum alloy and connected below the heating plate;
a surface of the heating plate corresponding to the cooling plate is defined as a first surface, a surface of the cooling plate corresponding to the heating plate is defined as a second surface, a gap space is provided between the heating plate and the cooling plate, the gap space extends in a direction along the first surface and the second surface, and an alumite coating is provided on at least one or both of the first surface exposed to the gap space and the second surface exposed to the gap space;
heating the electrostatic chuck with the heating plate;
removing heat from the electrostatic chuck through the heating plate by the cooling plate through heat exchange via the gap space;
and adjusting a temperature of the substrate via the electrostatic chuck.
A method for processing a substrate. Filling the gap space with air or a heat transfer gas;
The method of claim 10. The processing includes forming a film on the substrate.
The method of claim 10.

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