Substrate support and substrate processing apparatus

Abstract

To appropriately reduce the consumption of an edge ring supported by a substrate support during plasma processing.SOLUTION: The stage 11 as a substrate support that supports the substrate W and the edge ring 13 on the upper surface thereof supports a substrate support portion constituted by the electrostatic chuck 112 that adsorbs the substrate and an edge ring disposed to surround the substrate. The substrate processing apparatus includes a ring holding member 113 having an edge-ring heater-electrode 113b therein, a base member 111 including a center mount 111c on which a substrate support is disposed and an outer periphery mount 111e on which the ring holding member is disposed on an outer periphery side of the center mount 112b, a first power-supply-terminal 112c disposed immediately below the substrate support and configured to supply power to the substrate-heater electrode-center, and a second power-supply-terminal 113b disposed immediately below the ring holding member and configured to supply power to the edge-ring heater-electrode. The thickness of the ring support is 40% or more of the thickness of the substrate support.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to a substrate support and a substrate processing apparatus. [Background technology]

[0002] Patent Document 1 discloses a substrate processing apparatus including a base disposed inside a processing vessel, the base having a flow path for a coolant extending to an inlet and an outlet, and a mounting table having an electrostatic chuck attached to the upper surface of the base via an adhesive and having a heater inside or on the lower surface thereof. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-172013 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure appropriately reduces the amount of wear of an edge ring disposed around a substrate supported by a substrate support during plasma processing. [Means for solving the problem]

[0005] In one aspect of the present disclosure, there is provided a substrate support for supporting a substrate and an edge ring on an upper surface thereof, the substrate support including: a substrate support portion having an electrostatic chuck for attracting the substrate and a substrate heater electrode within the electrostatic chuck; a ring support portion for supporting an edge ring arranged to surround the substrate and having an edge ring heater electrode therein; a base having a central mounting portion on which the substrate support portion is arranged and an outer peripheral mounting portion on which the ring support portion is arranged on the outer periphery of the central mounting portion; a first power supply terminal arranged directly below the substrate support portion for supplying power to the substrate heater electrode; and a second power supply terminal arranged directly below the ring support portion for supplying power to the edge ring heater electrode, wherein an upper surface of the outer peripheral mounting portion is located lower than an upper surface of the central mounting portion, and a thickness of the ring support portion is 40% or more of a thickness of the substrate support portion. [Effects of the Invention]

[0006] According to the present disclosure, in an edge ring disposed around a substrate supported by a substrate support, the amount of wear of the edge ring during plasma processing can be appropriately reduced. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a vertical cross-sectional view schematically illustrating an outline of the configuration of a plasma processing system according to an embodiment of the present invention. [Figure 2] 1 is a vertical cross-sectional view schematically illustrating the configuration of a mounting table according to an embodiment of the present invention. [Figure 3] 3 is an enlarged view showing a main part of the mounting table shown in FIG. 2.

[0023] FIG. [Figure 4] FIG. 10 is a plan view showing an example of division of temperature control regions whose temperatures are independently controlled by heaters. [Figure 5] 3 is an enlarged view of a main part showing another example of the installation position of the sealing member in the substrate support body shown in FIG. 2. FIG. [Figure 6] 3 is an enlarged view of a main part showing another example of the installation position of the sealing member in the substrate support body shown in FIG. 2. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] In a semiconductor device manufacturing process, a plasma processing apparatus generates plasma by exciting a processing gas, and processes a semiconductor substrate (hereinafter referred to as "substrate") placed on a mounting table using the plasma. The mounting table on which the substrate is placed is provided with an electrostatic chuck that attracts and holds the substrate to the mounting surface using, for example, Coulomb force.

[0009] Incidentally, a mounting table provided inside a chamber of a plasma processing apparatus is provided with an edge ring (also called a "focus ring") that surrounds the periphery of a substrate held by suction on a mounting surface, as disclosed in Patent Document 1. This edge ring is exposed to the internal space of the chamber (plasma processing space) during plasma processing, and is therefore worn out by the influence of plasma generated in the plasma processing space.

[0010] Countermeasures against edge ring wear during plasma processing include, for example, increasing the thickness of the edge ring itself or the ring holder that holds the edge ring on the upper surface of the mounting table. For example, by increasing the thickness of the edge ring itself, the margin for wear before the edge ring reaches a thickness that requires replacement can be increased, thereby extending the life of the edge ring. Furthermore, for example, by increasing the thickness of the ring holder, the impedance ratio to the substrate and electrostatic chuck changes, thereby reducing the plasma acting on the edge ring during plasma processing. In other words, the effect of the plasma on the edge ring is reduced, thereby reducing the amount of wear on the edge ring.

[0011] However, the structure of the conventional mounting table disclosed in Patent Document 1 does not allow for the thickness of the edge ring or the ring holder to be increased, making it impossible to appropriately extend the life of the edge ring or reduce its wear. Specifically, the structure of the conventional mounting table disclosed in Patent Document 1 does not allow for the attachment positions of the electrostatic chuck and the ring holder relative to the substrate of the mounting table to be changed, making it difficult to independently change the thickness of the edge ring or the ring holder. Thus, there is room for improvement in the structure of the conventional mounting table from the perspective of reducing the wear and extending the life of the edge ring.

[0012] The present disclosure has been made in consideration of the above circumstances, and aims to appropriately reduce the amount of wear of an edge ring disposed around a substrate supported by a substrate support during plasma processing. Hereinafter, a plasma processing system as a substrate processing apparatus including a mounting table according to one embodiment will be described with reference to the drawings. Note that in this specification and the drawings, elements having substantially the same functional configuration are designated by the same reference numerals, and redundant description will be omitted.

[0013] <Plasma processing system> First, a plasma processing system as a substrate processing apparatus according to this embodiment will be described. Fig. 1 is a longitudinal sectional view showing the outline of the configuration of a plasma processing system 1. The plasma processing system 1 has a capacitively coupled plasma processing apparatus, and performs plasma processing such as etching, film formation, diffusion, etc. on a substrate W to be processed.

[0014] In one embodiment, the plasma processing system 1 includes a plasma processing apparatus 1a and a control unit 1b. The plasma processing apparatus 1a includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1a also includes a mounting table 11 and an upper electrode showerhead 12 according to this embodiment. The mounting table 11 is disposed in a lower region of a plasma processing space 10s in the plasma processing chamber 10. The upper electrode showerhead 12 is disposed above the mounting table 11 and can function as part of the ceiling of the plasma processing chamber 10.

[0015] The mounting table 11 serving as a substrate support includes a base 111, an electrostatic chuck 112 disposed on the central upper surface of the base 111 and having a mounting surface for the substrate W, and a ring holder 113 disposed on the outer peripheral upper surface of the base 111 and having a mounting surface for an edge ring 13 (described below). The mounting table 11 is fixed to the floor of the plasma processing chamber 10 via a mounting base 114. The detailed configuration of the mounting table 11 will be described later.

[0016] An edge ring 13 having an annular shape is provided on the support surface of the ring holding member 113 so as to surround the support surface of the electrostatic chuck 112 for supporting the substrate W in a plan view. The edge ring 13 is provided, for example, to improve the uniformity of the plasma processing. The edge ring 13 is made of a material appropriately selected depending on the plasma processing to be performed, and may be made of, for example, silicon, silicon carbide (SiC), or quartz.

[0017] It is preferable that the upper surface of the substrate W placed on the support surface of the electrostatic chuck 112 and the upper surface of the edge ring 13 placed on the support surface of the ring holding member 113 are approximately aligned in a plan view, as shown in FIG.

[0018] The upper electrode showerhead 12 is configured to supply one or more process gases from a gas supply 20 to the plasma processing space 10s. In one embodiment, the upper electrode showerhead 12 has a gas inlet 12a, a gas diffusion chamber 12b, and multiple gas outlets 12c. The gas inlet 12a is in fluid communication with the gas supply 20 and the gas diffusion chamber 12b. The multiple gas outlets 12c are in fluid communication with the gas diffusion chamber 12b and the plasma processing space 10s. In one embodiment, the upper electrode showerhead 12 is configured to supply one or more process gases from the gas inlet 12a through the gas diffusion chamber 12b and the multiple gas outlets 12c to the plasma processing space 10s.

[0019] The gas supply 20 may include one or more gas sources 21 and one or more flow controllers 22. In one embodiment, the gas supply 20 is configured to supply one or more process gases from respective gas sources 21 to the gas inlet 12a via respective flow controllers 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply 20 may include one or more flow modulation devices to modulate or pulse the flow rate of one or more process gases.

[0020] The power supply 30 includes a radio frequency (RF) generator 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. In one example, the RF generator 31 includes a first RF generator 31a configured to generate a source RF signal for generating the plasma, and a second RF generator 31b configured to generate a bias RF signal for attracting ions in the plasma to the substrate W.

[0021] The first RF generator 31a is coupled to the mounting table 11 and / or the upper electrode showerhead 12 via at least one impedance matching circuit and is configured to generate a source RF signal (source RF power). This generates plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the first RF generator 31a can function as at least a part of the plasma generator. In one embodiment, the source RF signal has a frequency of 27 MHz to 100 MHz.

[0022] The second RF generator 31b is coupled to the mounting table 11 via at least one impedance matching circuit and configured to generate a bias RF signal (bias RF power). The second RF generator 31b may be coupled to the substrate 111, which functions as a lower electrode in the mounting table 11, or to a bias electrode (not shown) provided in the electrostatic chuck 112. By supplying the bias RF signal to the mounting table 11, a bias potential is generated on the substrate W, and ions in the plasma can be attracted to the substrate W. The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency between 100 kHz and 60 MHz. In one embodiment, the second RF generator 31b may be configured to generate multiple bias RF signals having different frequencies. Note that in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0023] The power supply 30 may also include a DC power supply 32 coupled to the plasma processing chamber 10. For example, the DC power supply 32 includes a first DC generator 32a and / or a second DC generator 32b. In one embodiment, the first DC generator 32a is coupled to the mounting table 11 and configured to generate a first DC signal. The first DC generator 32a may be coupled to the substrate 111, which functions as a lower electrode, or to a bias electrode provided in the electrostatic chuck 112, similar to the bias RF signal. The generated first DC signal is applied to the mounting table 11. In one embodiment, the second DC generator 32b is connected to the upper electrode showerhead 12 and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode showerhead 12.

[0024] In various embodiments, at least one of the first DC signal and the second DC signal may be pulsed. In this case, the pulsed first DC signal and / or second DC signal (hereinafter also referred to as "voltage pulse") is applied to the mounting table 11 and / or the upper electrode showerhead 12. The voltage pulse may have a rectangular, trapezoidal, triangular, or combination thereof. In one embodiment, a waveform generator for generating a voltage pulse from a DC signal is connected between the first DC generator 32a and the mounting table 11. Therefore, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to the upper electrode showerhead 12. The voltage pulse may have either a positive polarity or a negative polarity. The first DC generator 32a may be provided together with the second RF generator 31b or may be provided instead of the second RF generator 31b.

[0025] The exhaust system 40 may be connected to an exhaust port 10e, for example, at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure valve and a vacuum pump. The vacuum pump may include a turbomolecular pump, a roughing pump, or a combination thereof.

[0026] In one embodiment, the controller 1b processes computer-executable instructions that cause the plasma processing apparatus 1a to perform various steps described in this disclosure. The controller 1b may be configured to control each element of the plasma processing apparatus 1a to perform various steps described herein. In one embodiment, part or all of the controller 1b may be included in the plasma processing apparatus 1a. The controller 1b may include, for example, a computer 51. The computer 51 may include, for example, a processor (CPU: Central Processing Unit) 511, a storage unit 512, and a communication interface 513. The processor 511 may be configured to perform various control operations based on programs stored in the storage unit 512. The storage unit 512 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 513 may communicate with the plasma processing apparatus 1a via a communication line such as a local area network (LAN).

[0027] <Placement table> Next, a detailed configuration of the above-mentioned mounting table 11 will be described. Fig. 2 is a vertical cross-sectional view schematically showing the outline of the configuration of the mounting table 11. Fig. 3 is an enlarged view of a main part showing an enlarged outer periphery of the mounting table 11 shown in Fig. 2. As shown in Fig. 2, the mounting table 11 according to this embodiment has a base material 111, an electrostatic chuck 112, and a ring holding member 113.

[0028] The upper surface of the central portion of the substrate 111 forms a central mounting portion 111c on which the electrostatic chuck 112 is mounted. The upper surface of the outer periphery of the substrate 111 forms an outer periphery mounting portion 111e on which the ring holder 113 is mounted. The height of the upper surface of the central mounting portion 111c is set higher than the height of the upper surface of the outer periphery mounting portion 111e. In other words, the ring holder 113 is mounted at a lower position on the substrate 111 in a side view than the electrostatic chuck 112. Furthermore, as shown in FIG. 3, it is desirable that the height position of the upper surface of the central mounting portion 111c be set higher than the height position of the upper surface of the ring holder 113 mounted on the outer periphery mounting portion 111e.

[0029] A coolant flow path 111a is formed inside the base material 111. A chiller unit (not shown) is connected to the coolant flow path 111a, and a coolant (e.g., cooling water) supplied from the chiller unit is circulated inside the coolant flow path 111a to cool the mounting table 11 and the substrate W mounted on the mounting table 11 to a desired temperature.

[0030] Base material 111 is made of, for example, aluminum or ceramic, and functions as a lower electrode in plasma processing system 1.

[0031] The electrostatic chuck 112 constituting the substrate support portion is mounted on the central mounting portion 111c of the base material 111 via, for example, an adhesive layer (not shown). The electrostatic chuck 112 has, on its upper surface, a mounting surface for electrostatically attracting the substrate W. The electrostatic chuck 112 is made of, for example, a dielectric material such as ceramic (hereinafter also referred to as a "first dielectric material").

[0032] Inside the electrostatic chuck 112, a substrate attracting electrode 112a for attracting the substrate W and a substrate heater electrode 112b for heating the substrate W are provided.

[0033] A DC power supply (not shown; hereinafter, also referred to as an "adsorption power supply") is connected to the substrate adsorption electrode 112a via, for example, a switch. The electrostatic chuck 112 can adsorb and hold the substrate W on the mounting surface by Coulomb force generated when a DC voltage is applied from the adsorption power supply to the substrate adsorption electrode 112a.

[0034] A power supply (not shown; hereinafter, also referred to as a "first heater power supply") is connected to the substrate heater electrode 112b via, for example, a switch. The power supply may be a DC power supply or an AC power supply. The substrate heater electrode 112b may be provided below the substrate chucking electrode 112a and above the above-mentioned coolant flow path 111a. The substrate heater electrode 112b is heated by power supplied from the first heater power supply, thereby adjusting the temperature of the substrate W placed on the electrostatic chuck 112 to a desired temperature. In this embodiment, the electrostatic chuck 112 may be divided into a plurality of regions in a plan view. The plurality of regions may be, for example, the substrate temperature control regions Z shown in FIG. 4. The substrate heater electrode 112b may be composed of a plurality of segment electrodes. In this case, each of the plurality of segment electrodes may be arranged in each of the plurality of regions. In such a configuration, the magnitude of the power supplied to each segment electrode may be configured to be independently controllable by the control unit 1b. This allows the temperature of the substrate W to be independently adjusted for each of the substrate temperature control regions Z. The number and shape of the substrate temperature control regions Z are not limited to those shown in the example and may be set as desired.

[0035] In one embodiment, the electrostatic chuck 112 may be configured with a first dielectric and a first electrode within the first dielectric. The first electrode may include at least one electrode selected from the group consisting of a substrate attracting electrode, a substrate heater electrode, and a substrate bias electrode. In one example, the electrostatic chuck 112 is configured with a first dielectric and a substrate attracting electrode and a substrate bias electrode within the first dielectric. The substrate bias electrode may be connected to the second RF generator 31b or the first DC generator 32a via, for example, a switch. By supplying a bias RF signal or a first DC signal to the substrate bias electrode during plasma processing, ions in the plasma can be attracted to the substrate W. In one embodiment, the electrostatic chuck 112 may further include a substrate heater electrode within the first dielectric in addition to the substrate attracting electrode and the substrate bias electrode.

[0036] As shown in FIG. 2, a first power supply terminal 112c is disposed below the electrostatic chuck 112. The first power supply terminal 112c may be disposed directly below the electrostatic chuck 112. The first power supply terminal 112c may be disposed in a through-hole that penetrates the central mounting portion 111c of the substrate 111 in the thickness direction. The first power supply terminal 112c is configured to be able to supply power to a substrate heater electrode 112b disposed in the electrostatic chuck 112. The first power supply terminal 112c may be configured to be able to supply power to the substrate chucking electrode 112a and / or the substrate bias electrode together with or instead of the substrate heater electrode 112b. That is, the first power supply terminal 112c may be configured to be able to supply power to at least one electrode selected from the group consisting of a substrate chucking electrode, a substrate heater electrode, and a substrate bias electrode.

[0037] The ring holding member 113 serving as a ring support is placed on the outer peripheral mounting portion 111e of the mounting table 11 via, for example, an adhesive layer (not shown). The ring holding member 113 may be configured to support the edge ring 13 via an adhesive (not shown) such as a polymer sheet. The ring holding member 113 is made of, for example, a dielectric material such as ceramic (hereinafter also referred to as a "second dielectric material").

[0038] An edge ring heater electrode 113 a for heating the edge ring 13 is provided inside the ring holding member 113 .

[0039] A power supply (not shown; hereinafter, also referred to as a "second heater power supply") is connected to the edge ring heater electrode 113a via, for example, a switch. The power supply may be a DC power supply or an AC power supply. The second heater power supply may be the same as or different from the first heater power supply. The edge ring heater electrode 113a is heated by receiving power from the second heater power supply, thereby adjusting the edge ring 13 placed on the ring holder 113 to a desired temperature. In this embodiment, the edge ring heater electrodes 113a may be arranged circumferentially inside the ring holder 113. The number, shape, and arrangement of the edge ring heater electrodes 113a are not limited and can be determined arbitrarily. For example, a plurality of ring-shaped electrodes with different radii may be prepared as the edge ring heater electrodes 113a, and these ring-shaped electrodes may be arranged concentrically inside the ring holder 113.

[0040] In one embodiment, the ring holder 113 may be configured with a second dielectric and a second electrode within the second dielectric. The second electrode may include at least one electrode selected from the group consisting of an edge ring chucking electrode, an edge ring heater electrode, and an edge ring bias electrode. The second electrode may also include at least two electrodes selected from the group consisting of an edge ring chucking electrode, an edge ring heater electrode, and an edge ring bias electrode. In one example, the ring holder 113 is configured with a second dielectric and an edge ring bias electrode within the second dielectric. The edge ring bias electrode may be connected to the second RF generator 31b or the first DC generator 32a via, for example, a switch. By supplying a bias RF signal or a first DC signal to the edge ring bias electrode during plasma processing, ions in the plasma can be attracted to the edge ring 13. In one embodiment, the ring holder 113 may further include an edge ring heater electrode within the second dielectric in addition to the edge ring bias electrode. Furthermore, as will be described later, when the ring holding member 113 is configured to support the edge ring 13 by an electrostatic chuck, an edge ring attracting electrode may be further provided within the second dielectric body.

[0041] As shown in FIG. 2, a second power supply terminal 113b is disposed below the ring holding member 113. The second power supply terminal 113b may be disposed directly below the ring holding member 113. The second power supply terminal 113b may be disposed in a through-hole that penetrates the outer periphery mounting portion 111e of the substrate 111 in the thickness direction. The second power supply terminal 113b is configured to be able to supply power to the edge-ring heater electrode 113a disposed in the ring holding member 113. The second power supply terminal 113b may be configured to be able to supply power to the edge-ring attraction electrode and / or the edge-ring bias electrode together with or instead of the edge-ring heater electrode 113a. That is, the second power supply terminal 113b may be configured to be able to supply power to at least one electrode selected from the group consisting of the edge-ring attraction electrode, the edge-ring heater electrode, and the edge-ring bias electrode.

[0042] In this embodiment, the edge ring 13 is mounted on the outer peripheral mounting portion 111e of the ring holding member 113 via an adhesive, but the method for mounting the edge ring 13 is not limited to this. For example, an edge ring attracting electrode may be provided inside the ring holding member 113, and a DC voltage may be applied to the electrode to attract and hold the edge ring 13 by Coulomb force. In other words, the ring holding member 113 may be configured as an annular electrostatic chuck.

[0043] As described above, it is desirable that the height of the upper surface of the edge ring 13 placed on the upper surface of the ring holding member 113 be approximately equal to the height of the upper surface of the substrate W placed on the upper surface of the electrostatic chuck 112. In other words, it is desirable that the thicknesses of the ring holding member 113 and the edge ring 13 be determined so that the height of the upper surface of the edge ring 13 and the height of the upper surface of the substrate W are approximately equal to each other.

[0044] The mounting table 11 may also be formed with a gas flow path (not shown) for supplying a heat transfer gas (backside gas) such as helium gas to the backside of the substrate W placed on the mounting surface. A gas supply source (not shown) is connected to the gas flow path, and the substrate W placed on the mounting table 11 may be controlled to a desired temperature by supplying the heat transfer gas from the gas supply source.

[0045] As described above, the electrostatic chuck 112 and the ring holder 113 are mounted on the upper surface of the substrate 111 via an adhesive layer. However, the adhesive layer may be worn away by radicals generated during plasma processing, which may cause the electrostatic chuck 112 and the ring holder 113 to peel off from the substrate 111. Therefore, it is preferable to provide a sealing member 115 (e.g., an O-ring) on ​​the mounting table 11 to protect the adhesive layer from the plasma processing (radicals). The sealing member 115 may be sandwiched between two or more of the electrostatic chuck 112, the ring holder 113, and the central mounting portion 111c of the substrate 111. For example, as shown in FIG. 3 , if the upper surface of the central mounting portion 111c is set higher than the upper surface of the ring holder 113, the electrostatic chuck 112 may have a larger diameter than the central mounting portion 111c of the substrate 111, and the sealing member 115 may be provided at the overlapping portion between the electrostatic chuck 112 and the ring holder 113 in a plan view. In this configuration, when the substrate W is subjected to plasma processing, the exposure of the adhesive layer to plasma can be reduced, thereby suppressing wear of the adhesive layer.

[0046] The arrangement of the sealing member 115 is not limited to the example shown in FIG. 3, as long as it can suppress the wear of the adhesive layer due to radicals.

[0047] 5, the sealing member 115 may be placed so as to be sandwiched from the left and right (horizontally) between the electrostatic chuck 112 and the ring holding member 113. In this case, a notch N for holding the sealing member 115 may be formed at the contact portion between the sealing member 115 and the ring holding member 113, i.e., on the upper part of the inner circumferential surface of the ring holding member 113.

[0048] 6, the sealing member 115 may be placed so as to be sandwiched vertically and horizontally (horizontally) between the electrostatic chuck 112 and the ring holding member 113. In this case, a notch N for holding the sealing member 115 may be formed in the upper part of the inner circumferential surface of the ring holding member 113.

[0049] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0050] <Functions and Effects of the Mounting Table According to the Present Embodiment> According to the mounting table 11 of this embodiment, the height position of the outer peripheral mounting portion 111e of the base material 111 is set to a position lower than that of the central mounting portion 111c, so that the electrostatic chuck 112 for mounting the substrate W on its upper surface and the ring holding member 113 for mounting the edge ring 13 on its upper surface are configured as separate bodies. As a result, the thickness of the ring holding member 113 for holding the edge ring 13 and the thickness of the edge ring 13 itself can be changed independently of the electrostatic chuck 112.

[0051] In the present embodiment, it is desirable to determine the thicknesses of the ring holding member 113 and the edge ring 13 so that the height of the upper surface of the edge ring 13 is approximately equal to the height of the upper surface of the substrate W. In this case, since the height position of the outer peripheral mounting portion 111e is set to a position lower than the height position of the central mounting portion 111c as described above, at least one of the thickness of the ring holding member 113 and the thickness of the edge ring 13 relative to the thickness of the electrostatic chuck 112 can be set larger than in the conventional case.

[0052] Specifically, as described above, by setting the height position of the central mounting portion 111c higher than the height position of the upper surface of the ring holding member 113 mounted on the outer peripheral mounting portion 111e as shown in Fig. 3, the thickness of the edge ring 13 itself can be made larger than that of the conventional one, more specifically, equal to or greater than the thickness of the electrostatic chuck 112. By increasing the thickness of the edge ring 13 itself in this way, the life of the edge ring 13 can be appropriately extended.

[0053] Specifically, by increasing the thickness of the ring holding member 113 (edge ​​ring 13) in this manner, it is possible to adjust the impedance ratio of the ring holding member 113 (edge ​​ring 13) to the electrostatic chuck 112. In other words, the heat input ratio to the edge ring 13 during plasma processing is reduced, thereby reducing the amount of wear on the edge ring 13 and more appropriately extending the life of the edge ring 13.

[0054] As a result of intensive research, the present inventors have found that it is desirable that the thickness of the ring holding member 113 be at least 40% or more, and preferably 50% or more, of the thickness of the electrostatic chuck 112, from the viewpoints of the wear amount of the edge ring 13 and the strength of the ring holding member 113. Based on this finding, the ring holding member 113, which has conventionally been formed to have a thickness about half that of the electrostatic chuck 112, can be formed to have, for example, substantially the same thickness as the electrostatic chuck 112, thereby making it possible to reduce the heat input ratio to the edge ring 13 (the wear amount of the edge ring 13) by about 10%.

[0055] In order to properly perform plasma processing on the substrate W in the plasma processing system 1, it is necessary to maintain uniformity in the temperature of the substrate W placed on the electrostatic chuck 112 and to maintain a desired temperature difference between the substrate W and the edge ring 13.

[0056] In this regard, according to the present embodiment, as described above, the electrostatic chuck 112 on which the substrate W is placed and the ring holding member 113 on which the edge ring 13 is placed are configured as separate bodies. As a result, the electrostatic chuck 112 and the ring holding member 113 form a vacuum heat insulating structure in the plasma processing space 10s inside the plasma processing apparatus 1a, and the temperatures of the electrostatic chuck 112 and the ring holding member 113 can be controlled independently, thereby appropriately maintaining the temperature difference between the substrate W and the edge ring 13.

[0057] 4, the electrostatic chuck 112 (substrate W) is configured so that the temperature of each of the plurality of substrate temperature control regions Z can be independently controlled by a plurality of substrate heater electrodes 112b provided inside the electrostatic chuck 112. This makes it possible to appropriately maintain uniformity in the in-plane temperature of the surface of the electrostatic chuck 112 (substrate W).

[0058] Specifically, the inventors conducted an investigation and found that the surface temperature of the electrostatic chuck 112 could be controlled to approximately 20°C while maintaining the surface temperature of the ring holding member 113 at approximately 90°C (control of the temperature difference between the substrate W and the edge ring 13). Furthermore, the variation in the surface temperature of the electrostatic chuck 112 could be controlled to within Δ1.5°C (control of the in-plane temperature of the substrate W). In other words, the desired temperature difference between the substrate W and the edge ring 13 could be maintained while ensuring uniformity in the in-plane temperature of the substrate W.

[0059] In the above embodiment, the second power supply terminal 113b for applying a voltage to the edge ring heater electrode 113a and a DC power supply (not shown) for applying a DC voltage to the edge ring attraction electrode are connected to the ring holding member 113. However, the ring holding member 113 may further be connected to a DC power supply (not shown) for applying a DC voltage to the ring holding member 113 when the edge ring 113 is worn down by plasma processing, for example.

[0060] If the height position of the upper surface of the edge ring 13 changes due to wear of the edge ring 13, this will cause a change in the shape of the sheath formed during plasma processing. Specifically, wear of the edge ring 13 will cause a difference in the sheath height between the substrate W and the edge ring 13. If the sheath shape changes in this way, there is a risk that the accuracy of the plasma processing will deteriorate.

[0061] Therefore, as described above, when the edge ring 13 is worn, a DC voltage from a DC power supply is applied to the ring holding member 113, thereby canceling out the change in the sheath shape caused by the wear of the edge ring 13. More specifically, by adjusting the DC voltage applied to the edge ring 13 in accordance with the wear of the edge ring 13, the sheath height of the edge ring 13 can be adjusted, and thereby the sheath height of the substrate W and the sheath height of the edge ring 13 can be aligned.

[0062] There is no particular limitation on the method of applying a DC voltage from a DC power supply to the edge ring 13. For example, when the amount of wear of the edge ring 13 is large (when the sheath height of the edge ring 13 is equal to or smaller than a predetermined threshold), a DC voltage may be applied to the edge ring 13, and when the amount of wear of the edge ring 13 is small (when the sheath height of the edge ring 13 exceeds the predetermined threshold), the application of the DC voltage may be stopped.

[0063] In addition, when the amount of wear of the edge ring 13 is large (when the sheath height of the edge ring 13 is equal to or less than a predetermined threshold), the DC voltage applied to the edge ring 13 may be changed stepwise or continuously.

[0064] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0065] For example, in the plasma processing system 1 of the above embodiment, the case where capacitively coupled plasma (CCP) is generated in the plasma processing device 1a has been described as an example, but the plasma generated in the plasma processing device 1a may also be, for example, inductively coupled plasma (ICP). [Explanation of symbols]

[0066] 1a Plasma processing device 11 Mounting table 13 Edge Ring 111 Base material 111c Center placement part 111e Outer holder 112 Electrostatic Chuck 112b Substrate heater electrode 112c First power supply terminal 113 Ring retaining member 113a Edge ring heater electrode 113b Second power supply terminal W substrate

Claims

1. 1. A substrate support disposed in a substrate processing apparatus for plasma processing a substrate, comprising: a substrate support portion having an electrostatic chuck for attracting the substrate and a substrate heater electrode within the electrostatic chuck; a base including a ring support portion that supports an edge ring disposed so as to surround the substrate and has an edge ring heater electrode therein, a central mounting portion on which the substrate support portion is disposed, and an outer peripheral mounting portion on which the ring support portion is disposed on the outer periphery side of the central mounting portion; a first power supply terminal disposed directly below the substrate support portion and configured to supply power to the substrate heater electrode; a second power supply terminal disposed directly below the ring support portion and configured to supply power to the edge ring heater electrode; Including, an upper surface of the outer peripheral mounting portion is located at a lower position than an upper surface of the central mounting portion; A substrate support, wherein the thickness of the ring support is 40% or more of the thickness of the substrate support.

2. The substrate support of claim 1 , wherein the thickness of the ring support is 50% or more of the thickness of the substrate support.

3. The substrate support according to claim 1 , wherein an upper surface of the central mounting portion is located higher than an upper surface of the ring support portion mounted on the outer periphery mounting portion.

4. The substrate support according to any one of claims 1 to 3, wherein the edge ring has a thickness greater than a thickness of the substrate support portion.

5. 5. The substrate support according to claim 1, further comprising a DC power supply that applies a DC voltage to the ring support portion so as to counteract a change in sheath shape caused by wear of the edge ring due to the plasma processing.

6. The DC power supply is The substrate support of claim 5 , wherein a DC voltage is applied to the edge ring when the wear of the edge ring exceeds a predetermined threshold.

7. the electrostatic chuck is divided into a plurality of regions in a plan view, the substrate heater electrode is composed of a plurality of segment electrodes, 7. The substrate support according to claim 1, wherein each of the plurality of segment electrodes is arranged in one of the plurality of regions.

8. The substrate support of claim 7 , wherein the power supplied to each of the plurality of segment electrodes is independently controllable.

9. The substrate support according to any one of claims 1 to 8, comprising a plurality of the edge ring heater electrodes.

10. The substrate support according to any one of claims 1 to 9, wherein the substrate support and the ring support are mounted on the base material via an adhesive layer, and are sandwiched between two or more of the electrostatic chuck, the ring support, and the central mounting portion, and further comprises a sealing member that suppresses exposure of the adhesive layer to plasma when the substrate is subjected to plasma processing.

11. The substrate support according to any one of claims 1 to 10, wherein the ring support includes an electrostatic chuck for attracting the edge ring.

12. a substrate support for supporting a substrate, the substrate support including a first dielectric, and a substrate chucking electrode and a substrate bias electrode within the first dielectric; a ring support for supporting an edge ring disposed to surround the substrate, the ring support comprising a second dielectric and an edge ring bias electrode within the second dielectric; a base material including a central mounting portion on which the substrate support portion is disposed, and an outer peripheral mounting portion on which the ring support portion is disposed on the outer periphery side of the central mounting portion; Including, an upper surface of the outer peripheral mounting portion is located at a lower position than an upper surface of the central mounting portion; A substrate support, wherein the thickness of the ring support is 40% or more of the thickness of the substrate support.

13. the substrate support further includes a substrate heater electrode for heating the substrate; The substrate support of claim 12 , wherein the ring support further comprises an edge ring heater electrode for heating the edge ring.

14. a first power supply terminal disposed below the substrate support portion for supplying power to the substrate heater electrode; The substrate support of claim 13 , further comprising: a second power supply terminal disposed below the ring support for supplying power to the edge ring heater electrode.

15. a substrate support for supporting a substrate, the substrate support comprising a first dielectric and a first electrode within the first dielectric; a ring support for supporting an edge ring disposed to surround the substrate, the ring support comprising a second dielectric and a second electrode within the second dielectric; a base material including a central mounting portion on which the substrate support portion is disposed, and an outer peripheral mounting portion on which the ring support portion is disposed on the outer periphery side of the central mounting portion; Including, an upper surface of the outer peripheral mounting portion is located at a lower position than an upper surface of the central mounting portion; A substrate support, wherein the thickness of the ring support is 40% or more of the thickness of the substrate support.

16. The substrate support according to claim 15 , wherein the first electrode comprises at least one electrode selected from the group consisting of a substrate attraction electrode, a substrate heater electrode, and a substrate bias electrode.

17. 17. The substrate support according to claim 15, wherein the second electrode includes at least one electrode selected from the group consisting of an edge ring attraction electrode, an edge ring heater electrode, and an edge ring bias electrode.

18. 17. The substrate support according to claim 15, wherein the second electrode includes at least two electrodes selected from the group consisting of an edge ring attraction electrode, an edge ring heater electrode, and an edge ring bias electrode.

19. A substrate processing apparatus for processing a substrate, a processing chamber for processing the substrate therein; a plasma generating unit; A substrate processing apparatus comprising: a substrate support according to any one of claims 1 to 18, which is disposed inside the processing chamber and supports the substrate.

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