Plasma processing apparatus, upper electrode assembly for use in plasma processing apparatus, method for manufacturing upper electrode assembly, and method for regenerating upper electrode assembly

Abstract

To effectively control the temperature of an electrode plate constituting an upper electrode assembly.SOLUTION: The present invention relates to a plasma processing apparatus that comprises: a plasma processing chamber; a substrate support part arranged in the plasma processing chamber; a lower electrode arranged in the substrate support part; an electric conductive member which is arranged above the substrate support part, has at least one refrigerant entrance and at least one refrigerant exit, and is connected to an RF potential or DC potential; and an upper electrode assembly, wherein the upper electrode assembly has: an electric conductive plate which is detachably connected to a reverse surface of the electric conductive member, and has one or a plurality of refrigerant flow passages communicating with the at least one refrigerant entrance and at least one refrigerant exit; an electrode plate which is arranged below the electric conductive plate; and an electric conductive joint sheet which is arranged between the electrode plate and the conductive plate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a plasma processing apparatus, an upper electrode assembly for use in a plasma processing apparatus, a method for manufacturing an upper electrode assembly, and a method for regenerating an upper electrode assembly. [Background technology]

[0002] Patent Document 1 discloses the configuration of a composite showerhead electrode assembly in a plasma processing apparatus. In Patent Document 1, an interface gel made of, for example, silicone is disposed between an electrode plate and a backing plate among the multiple members that make up the composite showerhead electrode assembly, and the temperature of the electrode plate is controlled while ensuring electrical conductivity.

[0003] Moreover, Patent Document 2 discloses an upper electrode structure of a plasma processing apparatus. In the upper electrode structure of Patent Document 2, the temperature of a first plate facing a plasma processing space is controlled by forming a flow path for a coolant in a second plate located above the first plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2012-500471 [Patent Document 2] JP 2015-216261 A Summary of the Invention [Problem to be solved by the invention]

[0005] The technology according to the present disclosure reduces the thermal resistance associated with the joining of members when the heat input to a processing chamber increases, and effectively regulates the temperature of the electrode plate that constitutes the upper electrode assembly. [Means for solving the problem]

[0006] One aspect of the present disclosure includes a plasma processing chamber, a substrate support disposed within the plasma processing chamber, a lower electrode disposed within the substrate support, a conductive member disposed above the substrate support, the conductive member having at least one coolant inlet and at least one coolant outlet, and connected to an RF potential or a DC potential, and an upper electrode assembly, the upper electrode assembly including: a conductive plate detachably connected to a lower surface of the conductive member, the conductive plate having one or more coolant flow paths communicating with the at least one coolant inlet and the at least one coolant outlet; an electrode plate disposed below the conductive plate; and a conductive bonding sheet disposed between the electrode plate and the conductive plate. The conductive bonding sheet is formed of a first conductive material having an Al-Mg alloy or an Al-Si-Mg alloy. A plasma processing apparatus. Effect of the Invention

[0007] According to the present disclosure, when the heat input to the processing chamber increases, the thermal resistance associated with the joining of members can be reduced and the temperature of the electrode plate constituting the upper electrode assembly can be effectively controlled. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is an explanatory diagram illustrating a schematic configuration of a plasma processing system. [Diagram 2] FIG. 2 is an explanatory diagram showing an enlarged view of a portion of the upper electrode assembly. [Diagram 3] FIG. 2 is a schematic explanatory diagram of a conductive plate having a conductive coating layer formed thereon. [Figure 4] FIG. 4 is a flow diagram showing a method for manufacturing an upper electrode assembly. [Diagram 5] FIG. 1 is a flow diagram showing a method for regenerating an upper electrode assembly. [Figure 6] FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. [Figure 7] FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. [Figure 8] FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. [Figure 9]FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. [Figure 10] FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. [Figure 11] FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. [Figure 12] FIG. 4 is an explanatory diagram showing an example of a specific shape of a refrigerant flow path. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] In the manufacturing process of semiconductor devices, a process gas supplied into a chamber is excited to generate plasma, and various plasma processes such as etching, film formation, and diffusion are performed on a semiconductor substrate (hereinafter simply referred to as "substrate") supported on a substrate support. These plasma processes are performed using, for example, a capacitively coupled plasma (CCP) plasma processing apparatus equipped with an upper electrode assembly that constitutes part of the chamber ceiling.

[0010] In recent semiconductor device manufacturing processes, in response to demands for finer patterns formed on substrate surfaces, plasma processing equipment is required to have high-output RF (Radio Frequency) power sources and to perform, for example, deep etching. However, in deep etching, a further increase in RF output is required from the viewpoints of shortening the etching time and improving ion linearity, and the associated heat input to the chamber becomes a problem.

[0011] If the heat input to the chamber becomes excessive, there are concerns that the adhesion state of etching by-products and the like may change due to the rise in temperature, that the heat may damage the chamber structural members, etc. For this reason, from the viewpoint of uniformly controlling the plasma processing results for the substrate and preventing damage to the chamber structural members, there is a demand for improving the cooling performance of the chamber in response to the plasma heat input.

[0012] In the above-mentioned Patent Document 1, in the composite showerhead electrode assembly (upper electrode assembly) constituting the chamber, the electrode plate located on the plasma-exposed surface is attached via an interface gel to improve adhesion and thermal conductivity. Also, in the above-mentioned Patent Document 2, adhesion between the first plate and the second plate in the upper electrode structure is performed by electrostatic adhesion to improve adhesion and thermal conductivity.

[0013] However, since the interface gel described in the above Patent Document 1 is formed of, for example, silicone, which has low thermal conductivity and high thermal resistance, it is required to further improve the thermal conductivity when the plasma heat input becomes excessive. In addition, when the interface gel is formed of silicone, there is a problem that silicone has high volume resistance and it is necessary to provide a separate electrical contact with the electrode plate. Although the thermal conductivity can be improved by adding a filler to the silicone, the adhesion is deteriorated, so that the interface thermal resistance increases and is not practical. In addition, even if the electrostatic adsorption method described in the above Patent Document 2 is adopted, the effect of reducing the thermal resistance is insufficient when the heat input to the chamber is excessive, and there is room for further improvement.

[0014] The technology according to the present disclosure has been made in consideration of the above circumstances, and provides a technology that allows for more effective temperature control of an electrode plate constituting an upper electrode assembly than in the past, even when heat input to a chamber becomes excessive. Hereinafter, a plasma processing system according to an embodiment and a plasma processing method including an etching method according to the present 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 denoted by the same reference numerals, and duplicated description will be omitted.

[0015] <Plasma processing system> First, a plasma processing system according to the present embodiment will be described with reference to Fig. 1, which is a vertical cross-sectional view showing an outline of the configuration of the plasma processing system according to the present embodiment.

[0016] The plasma processing system includes a capacitively coupled plasma processing device 1 and a control unit 2. The plasma processing device 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing device 1 also includes a substrate support 11 and a gas inlet. The substrate support 11 is disposed in the plasma processing chamber 10. The gas inlet is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas inlet includes an upper electrode assembly 13. The upper electrode assembly 13 is disposed above the substrate support 11. In one embodiment, the upper electrode assembly 13 is attached to a conductive member 10b (ceiling) that constitutes the ceiling of the plasma processing chamber 10. Inside the plasma processing chamber 10, a plasma processing space 10s is formed, which is defined by the upper electrode assembly 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas exhaust port for exhausting gas from the plasma processing space 10s. The sidewall 10a is grounded. The upper electrode assembly 13 and the substrate support 11 are electrically insulated from the plasma processing chamber 10.

[0017] The substrate support 11 includes a main body 111 and a ring assembly 112. The upper surface of the main body 111 has a central region 111a (substrate support surface) for supporting a substrate (wafer) W, and an annular region 111b (ring support surface) for supporting the ring assembly 112. The annular region 111b surrounds the central region 111a in a plan view. The ring assembly 112 includes one or more annular members, at least one of which is an edge ring.

[0018] In one embodiment, the main body 111 includes a base 113 and an electrostatic chuck 114. The base 113 includes a conductive member. The conductive member of the base 113 functions as a lower electrode. The electrostatic chuck 114 is disposed on an upper surface of the base 113. The upper surface of the electrostatic chuck 114 has the above-mentioned central region 111a and annular region 111b.

[0019] Although not shown, the substrate support 11 may include a temperature adjustment module configured to adjust at least one of the ring assembly 112, the electrostatic chuck 114, and the substrate W to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path. The substrate support 11 may also include a heat transfer gas supply unit configured to supply a heat transfer gas (backside gas) between the back surface of the substrate W and the upper surface of the electrostatic chuck 114.

[0020] The gas supply 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply 20 is configured to supply at least one process gas from a respective gas source 21 through a respective flow controller 22 to the upper electrode assembly 13. 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 a flow rate of the at least one process gas.

[0021] The power source 30 includes an RF power source 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power source 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to a conductive member (lower electrode) of the substrate support 11 and / or a conductive member (upper electrode) of the upper electrode assembly 13. This causes a plasma to be formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power source 31 can function as at least a part of a plasma generating unit configured to generate a plasma from one or more processing gases in the plasma processing chamber 10. In addition, a bias potential is generated on the substrate W by supplying a bias RF signal to the lower electrode, and ion components in the formed plasma can be attracted to the substrate W.

[0022] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is coupled to the lower electrode and / or the upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 160 MHz. In one embodiment, the first RF generating unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the lower electrode and / or the upper electrode. The second RF generating unit 31b is coupled to the lower electrode via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a lower frequency than the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generating unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated bias RF signal or signals are provided to the lower electrode, and 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. The DC power supply 32 includes a first DC generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may be applied to another electrode, such as a chucking electrode in the electrostatic chuck 114. In one embodiment, the second DC generator 32b is connected to the upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode. In various embodiments, at least one of the first and second DC signals may be pulsed. It is noted that the first and second DC generators 32a, 32b may be provided in addition to the RF power supply 31, or the first DC generator 32a may be provided instead of the second RF generator 31b.

[0024] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the internal pressure of the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0025] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various steps described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform various steps described herein. In one embodiment, a part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 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 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0026] <Upper electrode assembly> Next, the above-mentioned upper electrode assembly 13 and components of the plasma processing apparatus 1 associated with the upper electrode assembly 13 will be described with reference to Fig. 2. Fig. 2 is an explanatory diagram showing an enlarged portion of the upper electrode assembly 13.

[0027] As shown in FIG. 2, in one embodiment, the upper electrode assembly 13 is attached to the lower surface of the conductive member 10b disposed above the substrate support 11, and includes an electrode plate 120 and a conductive plate 130. The conductive member 10b may constitute the ceiling of the plasma processing chamber 10, or may be attached to the ceiling of the plasma processing chamber 10. The electrode plate 120 and the conductive plate 130 are stacked vertically via a conductive bonding sheet 140. In other words, the upper electrode assembly 13 is stacked in the order of the electrode plate 120, the conductive bonding sheet 140, and the conductive plate 130 from the bottom. That is, the electrode plate 120 is disposed below the conductive plate 130.

[0028] The conductive member 10b is made of a conductive material (second conductive material) such as Al (aluminum). The electrode plate 120 is made of, for example, Si or SiC, and its lower surface is exposed to the plasma processing space 10s. That is, the electrode plate 120 has a plasma exposed surface that is exposed to plasma generated in the plasma processing space 10s. The electrode plate 120 functions as an upper electrode in plasma processing. The electrode plate 120 is formed with a plurality of gas inlets 13a penetrating in the thickness direction (vertical direction). The gas inlets 13a are connected to the gas supply unit 20 via a gas diffusion space 13b and a gas supply port 13c formed inside the conductive member 10b, and are configured to introduce at least one processing gas from the gas supply unit 20 into the plasma processing space 10s.

[0029] The conductive member 10b functions as a conductive support that supports the upper electrode assembly 13 including the electrode plate 120, the conductive bonding sheet 140, and the conductive plate 130 on its detachable surface 137 in a manner that allows it to be freely attached (detached). The upper electrode assembly 13 is fixed to the conductive member 10b by a fixing unit. For the fixing unit, various methods can be applied, such as a lifting type described in JP 2016-18768 A or JP 2016-18769 A, a screw fastening type described in US 2009 / 0095424 A1, or an adhesive type described in US 2021 / 0032752 A1.

[0030] At least one gas diffusion space 13b and at least one gas supply port 13c are formed inside the conductive member 10b. The gas diffusion space 13b and the gas supply port 13c are connected to the gas supply unit 20, and as described above, at least one processing gas from the gas supply unit 20 is configured to be introduced into the plasma processing space 10s through the gas inlet 13a formed in the electrode plate 120.

[0031] The conductive plate 130 has at least one coolant flow passage 131 therein, which is configured to adjust the temperature of the electrode plate 120, whose temperature varies due to plasma heat input, to a target temperature. A heat transfer fluid such as brine or gas flows through the conductive member 10b and circulates between the conductive member 10b and a chiller (not shown) outside the device via a flow passage inlet 133 and a flow passage outlet 134 at the upper part of the conductive member 10b. In one embodiment, the conductive member 10b has an upper surface and a lower surface. The conductive member 10b has at least one coolant inlet 133 and at least one coolant outlet 134 on its upper surface. The conductive member 10b has at least one first coolant flow passage that penetrates from the at least one coolant inlet 133 to the lower surface of the conductive member 10b. The conductive member 10b has at least one second coolant flow passage that penetrates from its lower surface to the at least one coolant outlet 134. The conductive plate 130 has one or more coolant flow paths 131 that communicate with at least one coolant inlet 133 via at least one first coolant flow path and communicate with at least one coolant outlet 134 via at least one second coolant flow path. The specific shape of the coolant flow path 131 will be described later with reference to Figs. 6 to 12. The conductive member 10b is connected to an RF potential or a DC potential. In one embodiment, the conductive member 10b is connected to an RF power source 31 or a DC power source 32.

[0032] In one embodiment, the conductive plate 130 is made of a highly tough conductive material (third conductive material) capable of applying a large pressing force. This is because stress such as screw torque may be applied when the conductive plate 130 is fixed to the conductive member 10b. In one embodiment, the conductive plate 130 is made of Mo (molybdenum) or a metal matrix composite material called MMC (Metal Matrix Composites).

[0033] In one embodiment, the conductive plate 130 is formed of a high resistance material such as Al-Si, AlN, or SiC. In this case, a conductive coating layer 139 is formed on the conductive plate 130. FIG. 3 is a schematic explanatory diagram of a case where the conductive coating layer 139 is formed on the conductive plate 130. As shown in FIG. 3, the conductive coating layer 139 may be formed so as to electrically connect the conductive member 10b and the conductive bonding sheet 140, and may be formed so as to cover, for example, the entire lower surface and side surfaces and a part of the upper surface of the conductive plate 130. The conductive coating layer 139 is formed of a conductive material such as aluminum.

[0034] In one embodiment, the conductive bonding sheet 140 is made of a metal called a solder metal, which has a melting point of 400°C to 1000°C. In one embodiment, the conductive bonding sheet 140 is made of an Al-Si alloy, an Al-Mg alloy, or an Al-Si-Mg alloy. The conductive plate 130 and the electrode plate 120 are bonded by the conductive bonding sheet 140 by a gas pressure pressurization process called hot pressing or HIP (Hot Isostatic Pressing). Therefore, the electrode plate 120 is bonded to the conductive plate 130 via the conductive bonding sheet 140 without any other fixing means.

[0035] The electrode plate 120 is, for example, a Si or SiC electrode. That is, the electrode plate 120 is made of Si or SiC. For example, in an etching process using plasma, the electrode plate 120 is exposed to the plasma and therefore needs to be regenerated or replaced as necessary due to peeling and deterioration over time with use, and adhesion of etching by-products, etc. Also, naturally, a new electrode plate 120 needs to be prepared even when starting plasma processing. A manufacturing method and a regenerating method for the upper electrode assembly 13 including this electrode plate 120 will be described later with reference to FIGS. 4 and 5.

[0036] In one embodiment, the difference in linear expansion coefficient between the conductive plate 130 and the electrode plate 120 is 2 ppm / °C or less. This is to suppress the generation of particles due to poor bonding between the conductive plate 130 and the electrode plate 120 and scratches, etc., when bonding the conductive plate 130 and the electrode plate 120 using the conductive bonding sheet 140 as a bonding layer. If the difference in linear expansion coefficient between the two exceeds 2 ppm / °C, thermal stress according to the linear expansion difference from the bonding temperature of the conductive bonding sheet 140 (melting temperature, 550°C for Al-Si-based solder) to room temperature acts on the bonding interface, which may cause damage. In addition, the thickness of the conductive bonding sheet 140 is configured to be smaller than that of the electrode plate 120.

[0037] <Substrate Processing Method Using Plasma Processing Apparatus> Next, a description will be given of an example of a method for processing the substrate W in the plasma processing apparatus 1 configured as above. In the plasma processing apparatus 1, various plasma processes such as an etching process, a film formation process, and a diffusion process are performed on the substrate W.

[0038] First, the substrate W is carried into the plasma processing chamber 10, and placed on the electrostatic chuck 114 of the substrate support portion 11. Next, a voltage is applied to the attraction electrode of the electrostatic chuck 114, so that the substrate W is attracted and held on the electrostatic chuck 114 by electrostatic force.

[0039] After the substrate W is attracted and held by the electrostatic chuck 114, the inside of the plasma processing chamber 10 is then depressurized to a predetermined vacuum level. Next, a processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s via the upper electrode assembly 13. In addition, a source RF power for plasma generation is supplied from the first RF generating unit 31a to the lower electrode, thereby exciting the processing gas to generate plasma. At this time, a bias RF power may be supplied from the second RF generating unit 31b. Then, in the plasma processing space 10s, the substrate W is subjected to plasma processing by the action of the generated plasma.

[0040] During plasma processing of the substrate W, the temperature of the electrode plate 120 of the upper electrode assembly 13 disposed adjacent to the plasma processing space 10s fluctuates due to plasma heat input. When such a temperature fluctuation occurs in the electrode plate 120, the result of the plasma processing of the substrate W may become non-uniform across its surface.

[0041] Therefore, in this embodiment, the temperature of the electrode plate 120 is controlled by the coolant flow passage 131 contained in the conductive plate 130. Specifically, when the temperature of the electrode plate 120 rises due to plasma heat input, for example, the temperature of the conductive plate 130 is lowered by passing a heat transfer fluid inside the coolant flow passage 131. This promotes heat transfer from the electrode plate 120 to the conductive plate 130, thereby lowering the temperature of the electrode plate 120.

[0042] In the upper electrode assembly 13 according to this embodiment, the electrode plate 120, the conductive bonding sheet 140, and the conductive plate 130 are laminated in this order, and the electrode plate 120 and the conductive plate 130 are bonded by a metal bonding method called metal solder. Therefore, in this embodiment, heat transfer in the vertical direction, which is the lamination direction of the electrode plate 120 and the conductive plate 130, is promoted, and the temperature of the electrode plate 120 can be effectively controlled.

[0043] When the plasma processing is terminated, the supply of the source RF power from the first RF generating unit 31a and the supply of the processing gas from the gas supply unit 20 are stopped. If a bias RF power has been supplied during the plasma processing, the supply of the bias RF power is also stopped.

[0044] Next, the electrostatic chuck 114 stops attracting and holding the substrate W, and electricity is removed from the substrate W after the plasma processing and the electrostatic chuck 114. Thereafter, the substrate W is detached from the electrostatic chuck 114, and is carried out from the plasma processing apparatus 1. In this manner, a series of plasma processing steps is completed.

[0045] <Manufacturing method and regeneration method of upper electrode assembly> FIG. 4 is a flow chart showing a method for manufacturing the above-mentioned upper electrode assembly 13, and FIG. 5 is a flow chart showing a method for regenerating the upper electrode assembly 13.

[0046] As shown in Fig. 4, the method for manufacturing the upper electrode assembly 13 according to the present embodiment is performed as follows. First, as shown in step S11, the electrode plate 120 and the conductive plate 130 are provided. Then, as shown in step S12, the conductive bonding sheet 140 is sandwiched between the electrode plate 120 and the conductive plate 130. In this state, as shown in step S13, the conductive bonding sheet 140 is melted by means of hot pressing or HIP (Hot Isostatic Pressing) to metal-bond the electrode plate 120 and the conductive plate 130. In this manner, the upper electrode assembly 13 is manufactured.

[0047] 5, the method for regenerating the upper electrode assembly 13 according to the present embodiment is performed as follows. First, as shown in step S21, the used upper electrode assembly 13 is collected. Then, in the collected upper electrode assembly 13, damage to the conductive plate 130 is checked, and if no damage is found, the following steps are performed. That is, as shown in step S22, the used electrode plate 120 (here, the first electrode plate) remaining in the collected upper electrode assembly 13 is removed. The electrode plate 120 may be removed by mechanical processing such as grinding or peeling by heating the conductive bonding sheet 140.

[0048] Then, as shown in step S23, the remaining used conductive adhesive sheet 140 (here, referred to as the first conductive adhesive sheet) is removed. The conductive adhesive sheet 140 may be removed by blasting. Here, in the case where the conductive coating layer 139 is formed on the conductive plate 130, the conductive coating layer 139 may also be removed at the same time.

[0049] Next, as shown in step S24, a new electrode plate 120 (here, assumed to be a second electrode plate) and a new conductive adhesive sheet 140 (here, assumed to be a second conductive adhesive sheet) are prepared. Then, the second conductive adhesive sheet 140 is sandwiched between the existing conductive plate 130 and the second electrode plate 120. Then, as shown in step S25, the second conductive adhesive sheet 140 is melted by means of hot pressing or HIP, and the second electrode plate 120 and the existing conductive plate 130 are metallically bonded. In this way, the upper electrode assembly 13 equipped with the new electrode plate 120 (second electrode plate) is completed using the existing conductive plate 130.

[0050] <Shape of the refrigerant flow path> As described above, the conductive plate 130 constituting the upper electrode assembly 13 according to this embodiment has at least one coolant flow passage 131 therein configured to adjust the temperature of the electrode plate 120, whose temperature varies due to plasma heat input, to a target temperature. The shape and configuration of the coolant flow passage 131 can be designed as desired according to the temperature distribution required for the plasma-exposed surface of the electrode plate 120. An example will be described below.

[0051] Figures 6 to 12 are explanatory diagrams showing an example of a specific shape of the refrigerant flow path 131. Figures 6 to 12(a) are diagrams showing the flow path in a plan view, and Figure 12(b) is a partially enlarged diagram of the flow path as seen at the AA cross section of Figure 12(a). Note that Figures 6 to 12 show the start point (S) and end point (G) of the refrigerant flow path 131.

[0052] The refrigerant flow path 131 may have a one-stroke shape with the start point and end point at approximately the same position as shown in Fig. 6. Alternatively, it may have a one-stroke shape with the start point and end point at different positions as shown in Fig. 7. Alternatively, it may be composed of multiple concentric flow paths with multiple start points and multiple end points as shown in Figs. 8 and 9. Alternatively, it may be configured with multiple flow paths having a predetermined geometric shape as shown in Fig. 10. Alternatively, it may be a radial flow path as shown in Fig. 11.

[0053] Also, as shown in FIG. 12, a plurality of minute flow paths using the jet flow method may be formed, and a flow of the coolant (see the arrows in FIG. 12(b)) may be created in each of the flow paths to perform temperature control.

[0054] <Effects of the technology disclosed herein> In the above embodiment, the electrode plate 120 and the conductive plate 130 in the upper electrode assembly 13 are joined by a joining method using the conductive joining sheet 140, which is, for example, a metal joint. This makes it possible to significantly reduce the thermal resistance at the interface accompanying the joining, and effectively regulate the temperature of the electrode plate 120. In addition, by joining the electrode plate 120 and the conductive plate 130 by a metal joint, it becomes possible to obtain an electrical contact between them.

[0055] In the above embodiment, the upper electrode assembly 13 is composed of the electrode plate 120, the conductive bonding sheet 140, and the conductive plate 130, and the conductive member 10b supports the upper electrode assembly 13 so as to be freely detachable at the detachment surface 137. As a result, even if regeneration or replacement is required due to peeling or deterioration of the electrode plate 120 over time or adhesion of etching by-products during plasma processing, the existing conductive plate 130 can be reused and the electrode plate 120 can be easily regenerated or replaced.

[0056] Moreover, the upper electrode assembly 13 according to the above embodiment has a configuration in which the conductive plate 130 has a coolant flow path 131 inside. This makes it possible to more effectively regulate the temperature of the electrode plate 120 compared to a conventional configuration in which the coolant flow path is provided inside the conductive member 10b, for example. In addition, since the coolant flow path 131 is provided inside the detachable conductive plate 130, the shape of the coolant flow path 131 can be changed by a simple method such as by attaching and detaching a member according to the temperature distribution required for the plasma-exposed surface of the electrode plate 120.

[0057] The embodiments disclosed herein should be considered as illustrative and not restrictive in all respects. The above-described embodiments may be omitted, substituted, or modified in various forms without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0058] 1. Plasma processing equipment 10 Plasma Processing Chamber 10b Conductive member 10s Plasma treatment space 13 Upper electrode assembly 120 Electrode Plate 130 Conductive Plate 131 Coolant flow path 133 Refrigerant inlet 134 Refrigerant outlet 140 Conductive adhesive sheet W substrate

Claims

1. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; a lower electrode disposed within the substrate support; an electrically conductive member disposed above the substrate support, the electrically conductive member having at least one coolant inlet and at least one coolant outlet, the electrically conductive member being connected to an RF potential or a DC potential; and an upper electrode assembly; The upper electrode assembly includes: a conductive plate removably connected to a lower surface of the conductive member and having one or more coolant flow passages communicating with the at least one coolant inlet and the at least one coolant outlet; an electrode plate disposed below the conductive plate; a conductive bonding sheet disposed between the electrode plate and the conductive plate, The conductive bonding sheet is formed of a first conductive material having an Al--Mg alloy or an Al--Si--Mg alloy.

2. 2. The plasma processing apparatus according to claim 1, wherein a difference in linear expansion coefficient between said conductive plate and said electrode plate is 2 ppm / [deg.] C. or less.

3. the conductive member is formed of a second conductive material; The plasma processing apparatus according to claim 1 , wherein the conductive plate is made of a third conductive material different from the second conductive material.

4. The plasma processing apparatus of claim 3 , wherein the third conductive material comprises Mo.

5. The plasma processing apparatus of claim 3 , wherein the second conductive material comprises Al.

6. 6. The plasma processing apparatus according to claim 1, wherein the electrode plate is made of Si or SiC.

7. 1. An upper electrode assembly for use in a plasma processing apparatus, comprising: a conductive plate detachably connected to the plasma processing apparatus and having one or more coolant flow paths; an electrode plate having a plasma exposed surface; A conductive bonding sheet is disposed between the electrode plate and the conductive plate, The conductive bonding sheet is formed of a first conductive material having an Al--Mg alloy or an Al--Si--Mg alloy.

8. 8. The upper electrode assembly of claim 7, wherein a difference in linear expansion coefficient between the conductive plate and the electrode plate is 2 ppm / [deg.] C. or less.

9. The upper electrode assembly according to claim 7 or 8, wherein the conductive plate is made of Mo.

10. The upper electrode assembly according to any one of claims 7 to 9, wherein the electrode plate is made of Si or SiC.

11. 1. A method for manufacturing an upper electrode assembly for use in a plasma processing apparatus, comprising: providing an electrode plate and a conductive plate; sandwiching a conductive bonding sheet between the electrode plate and the conductive plate; Hot pressing or HIP (Hot Isostatic Press) and bonding the electrode plate and the conductive plate via the conductive bonding sheet at a temperature of 400° C. to 1000° C. by a pressing (pressing). The method for manufacturing an upper electrode assembly, wherein the conductive bonding sheet comprises an Al--Mg alloy or an Al--Si--Mg alloy.

12. The method for manufacturing an upper electrode assembly according to claim 11 , wherein the conductive plate is made of Mo.

13. The method for manufacturing an upper electrode assembly according to claim 11 or 12, wherein the electrode plate is made of Si or SiC.

14. A method for regenerating an upper electrode assembly for use in a plasma processing apparatus, comprising the steps of: providing an upper electrode assembly, the upper electrode assembly including a conductive plate, a first electrode plate, and a first conductive bonding sheet bonding the conductive plate and the first electrode plate; removing the first electrode plate from the upper electrode assembly; removing the first conductive bonding sheet from the upper electrode assembly; sandwiching a second conductive bonding sheet between the conductive plate and a second electrode plate included in the upper electrode assembly; Hot pressing or HIP (Hot Isostatic Press) and bonding the second electrode plate and the conductive plate via the second conductive bonding sheet at a temperature of 400° C. to 1000° C. by a pressing (pressing), The method for regenerating an upper electrode assembly, wherein the second conductive bonding sheet comprises an Al--Mg alloy or an Al--Si--Mg alloy.

15. The method for regenerating an upper electrode assembly according to claim 14 , wherein the conductive plate is made of Mo.

16. The method for regenerating an upper electrode assembly according to claim 14 or 15, wherein the second electrode plate is made of Si or SiC.

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