Component for plasma processing apparatus, method for manufacturing the same, and plasma processing apparatus

Abstract

The component (10, 22) for a plasma processing apparatus is characterized by having a substrate (12, 23) and a heat conductive layer (13, 24) provided on one surface of the substrate, and the heat conductive layer (13, 24) contains at least one of a fluororesin and a fluoroelastomer.

Description

Technical Field

[0001] The present invention relates to a component for a plasma processing apparatus, a method for manufacturing the same, and a plasma processing apparatus.

[0002] This application claims priority based on Japanese Patent Application No. 2020-037969 filed on March 5, 2020, and Japanese Patent Application No. 2021-020070 filed on February 10, 2021, and incorporates the contents thereof herein. Background Art

[0003] Regarding a plasma processing apparatus such as a plasma etching apparatus or a plasma CVD apparatus used in a semiconductor device manufacturing process, a pair of electrodes are disposed opposite to each other in the vertical direction in a vacuum chamber. Generally, vent holes for allowing a gas for plasma generation to pass through are formed in the upper electrode, and the lower electrode serves as a stage on which a substrate to be processed such as a wafer can be fixed. Further, a structure is adopted in which a gas for plasma generation is supplied from the vent holes of the upper electrode (also referred to as a top-mounted electrode plate) to the substrate to be processed fixed to the lower electrode, and a high-frequency voltage is applied between the upper electrode and the lower electrode to generate plasma, thereby performing a process such as etching on the substrate to be processed.

[0004] In the plasma processing apparatus having the above structure, a cooling plate (also referred to as a cold plate) is disposed on the surface (back surface) of the upper electrode opposite to the lower electrode, and heat generated together with the plasma can be dissipated to the cooling plate via the upper electrode. In order to ensure the uniform heat property of the electrode by improving the thermal conductivity between the upper electrode and the cooling plate, a technique of disposing a heat conductive material between the upper electrode and the cooling plate is being studied. For example, a technique of disposing a silicone resin containing alumina filler between the upper electrode and the cooling plate is being studied (Patent Document 1).

[0005] Further, in order to suppress variations in etching processing conditions due to heat, a technique of disposing a heat conductive material (heat conductive sheet) having a high thermal conductivity between an annular support ring (focusing ring) and a stage (mounting table) is being studied (Patent Document 2), where the support ring supports the peripheral portion of the object to be processed, and the stage is used to dispose the focusing ring. Patent Document 2 describes a heat resistant silicone rubber containing granular alumina as the heat conductive material.

[0006] Patent Document 1: Japanese Patent No. 5762798

[0007] Patent Document 2: Japanese Unexamined Patent Application Publication No. 2012-9563

[0008] In order to ensure the uniform heat property of the electrode plate for a plasma processing apparatus used as the upper electrode in the long term, it is important to conduct the heat in the plasma processing apparatus to the cooling plate through the electrode plate for the plasma processing apparatus effectively in the long term. Therefore, regarding the heat conductive material disposed between the electrode plate for the plasma processing apparatus and the cooling plate, it is preferably less likely to deteriorate due to heat, plasma, or free radicals (generalized plasma) of by-products, and has high heat conductivity in the long term. Also, in order to prevent contamination (contamination of the substrate to be processed) caused by the deterioration of the heat conductive material, it is preferable that the heat conductive material has high plasma resistance. The same applies to the heat conductive material disposed between the annular focusing ring for supporting the peripheral portion of the object to be processed and the stage. Summary of the Invention

[0009] The present invention has been completed in view of the above circumstances, and an object thereof is to provide a component for a plasma processing apparatus such as an electrode plate or a focusing ring of a plasma processing apparatus that has a heat conductive material with excellent heat resistance and plasma resistance and has high uniform heat property in the long term, and a manufacturing method thereof. Moreover, an object of the present invention is to provide a plasma processing apparatus that is less likely to cause contamination.

[0010] In order to solve the above problems, a component for a plasma processing apparatus according to one aspect of the present invention is characterized by having a base material and a heat conductive layer provided on one surface of the base material, and the heat conductive layer contains at least one of a fluororesin and a fluoroelastomer.

[0011] According to the component for a plasma processing apparatus having this structure, since the heat conductive layer contains at least one of a fluororesin and a fluoroelastomer, the heat resistance and plasma resistance are excellent. Therefore, the component for a plasma processing apparatus has high uniform heat property in the long term and is less likely to cause contamination.

[0012] In the component for a plasma processing apparatus according to one aspect of the present invention, it is preferable that the material forming the base material is Si or SiC.

[0013] At this time, since the base material contains Si or SiC, the heat conductivity of the base material is improved. Therefore, the uniform heat property of the component for a plasma processing apparatus is improved.

[0014] In the component for a plasma processing apparatus according to one aspect of the present invention, it is preferable that the heat conductive layer contains a filler.

[0015] At this time, since the heat conductive layer contains a filler, the heat conductivity of the heat conductive layer is improved. Therefore, the uniform heat property of the component for a plasma processing apparatus is further improved.

[0016] In the component for a plasma processing apparatus according to one aspect of the present invention, it is preferable that the filler is at least one of alumina and boron nitride.

[0017] At this time, since the heat conductive layer contains at least one of alumina and boron nitride, the heat conductivity of the heat conductive layer is further reliably improved. Therefore, the heat uniformity of the component for a plasma processing apparatus is further improved.

[0018] In the component for a plasma processing apparatus according to one embodiment of the present invention, it is preferable that the fluororesin and the fluoroelastomer are compounds having a perfluoropolyether group.

[0019] At this time, since the heat conductive layer contains a compound having a perfluoropolyether group, the heat resistance and plasma resistance of the heat conductive layer are further improved. Therefore, the component for a plasma processing apparatus further has high heat uniformity for a long time and is less likely to cause contamination.

[0020] In the component for a plasma processing apparatus according to one embodiment of the present invention, it is preferable that the thickness of the heat conductive layer is in the range of 20 μm or more and 1 mm or less.

[0021] At this time, since the thickness of the heat conductive layer is 20 μm or more, the heat conductive layer is easily adhered to the cooling plate or the stage of the plasma processing apparatus, and the heat conductivity between the heat conductive layer and the cooling plate or between the heat conductive layer and the stage is improved. And since the thickness of the heat conductive layer is 1 mm or less, the heat conductivity of the heat conductive layer is also high. Therefore, the heat uniformity of the component for a plasma processing apparatus is further improved.

[0022] The component for a plasma processing apparatus according to one embodiment of the present invention may be an electrode plate for a plasma processing apparatus having a ventilation hole through which a gas for plasma generation passes.

[0023] At this time, the electrode plate for a plasma processing apparatus may also have the following structure: the substrate has a substrate having a plurality of the ventilation holes, and the heat conductive layer is provided on one surface of the substrate.

[0024] It may also have the following structure: the substrate is in a disc shape, and the thickness is in the range of 1 mm or more and 20 mm or less, the diameter of the ventilation hole is in the range of 0.1 mm or more and 1 mm or less, and the aspect ratio of the ventilation hole is 3 or more.

[0025] In the component for a plasma processing apparatus according to one embodiment of the present invention, the component for a plasma processing apparatus may also be a focusing ring.

[0026] At this time, the focusing ring may have the following structure: the substrate is an annular substrate having an annular flat portion and a protrusion formed on the outer peripheral side of one surface of the flat portion, and the heat conductive layer is provided on the surface of the flat portion opposite to the surface on which the protrusion is formed.

[0027] A method for manufacturing a component for a plasma processing apparatus according to an aspect of the present invention includes: a preparation step of preparing a substrate; a coating step of forming a coating layer on one surface of the substrate by coating a coating composition by heating or irradiating ultraviolet rays, the coating composition containing a fluorine-based compound that generates at least one of a fluorine-based resin and a fluorine-based elastomer; and a heat conductive layer forming step of generating a heat conductive layer containing at least one of a fluorine-based resin and a fluorine-based elastomer by heating the coating layer or irradiating the coating layer with ultraviolet rays.

[0028] According to the method for manufacturing a component for a plasma processing apparatus having this structure, a coating composition is coated on a substrate that is preformed into a specific shape to generate a heat conductive layer, so that various shaped components for a plasma processing apparatus, such as an electrode plate or a focusing ring for a plasma processing apparatus, can be effectively manufactured. Also, the contact between the heat conductive layer and the substrate is good, and the thermal resistance can be reduced. Further, regarding the obtained component for a plasma processing apparatus, since the heat conductive layer contains at least one of a fluorine-based resin and a fluorine-based elastomer, the heat resistance and plasma resistance are excellent, high heat uniformity is maintained over a long period, and contamination is less likely to occur.

[0029] In the method for manufacturing a component for a plasma processing apparatus according to an aspect of the present invention, it is preferable that the heat conductive layer contains a filler.

[0030] At this time, since the coating composition contains a filler, the formed heat conductive layer contains a filler, and the thermal conductivity is improved. Therefore, a component for a plasma processing apparatus with further improved heat uniformity can be manufactured.

[0031] In the method for manufacturing an electrode plate for a plasma processing apparatus according to an aspect of the present invention, the substrate may be a substrate having a plurality of ventilation holes, and the coating composition is coated on one surface of the substrate.

[0032] At this time, since a heat conductive layer is formed on a substrate having a plurality of ventilation holes, it is easy to align the positions of the ventilation holes of the substrate and the ventilation holes of the heat conductive layer. Therefore, it is possible to effectively manufacture an electrode plate for a plasma processing apparatus having ventilation holes. Further, as a method for manufacturing an electrode plate for a plasma processing apparatus, a method of separately manufacturing a heat conductive material (heat conductive layer) having a plurality of ventilation holes and placing the heat conductive material on the substrate can be considered. At this time, positional deviation is likely to occur when the heat conductive material is placed on the substrate. Therefore, although it is necessary to set the ventilation holes of the heat conductive material to a size that can absorb positional deviation, at this time, the contact surface between the cooling plate and the heat conductive plate of the plasma processing apparatus and the contact area between the heat conductive material and the substrate become smaller, and heat cannot be effectively transferred. Further, when forming ventilation holes in an independent heat conductive material, if the number of ventilation holes in the heat conductive material is large, the mechanical strength of the heat conductive material itself becomes weak, and it is difficult to handle it as an independent heat conductive material. In particular, since the mechanical strength of the heat conductive material itself is further weakened when the filler filling amount is large, the filler filling amount cannot be increased. On the other hand, according to the above manufacturing method, since it is not necessary to separately separate the heat conductive layer, it is possible to form a heat conductive layer having a large filler filling amount. Therefore, by the above manufacturing method, it is possible to manufacture an electrode plate for a plasma processing apparatus having heat uniformity and thermal stability.

[0033] In the method for manufacturing an electrode plate for a plasma processing apparatus according to one embodiment of the present invention, the substrate may be an annular substrate having an annular flat portion and a protrusion formed on the outer peripheral side of one surface of the flat portion, and the coating composition is applied to the surface of the flat portion opposite to the surface on which the protrusion is formed.

[0034] At this time, since the substrate is an annular substrate having an annular flat portion and a protrusion formed on the outer peripheral side of one surface of the flat portion, it is possible to effectively manufacture a focusing ring.

[0035] A plasma processing apparatus according to one embodiment of the present invention includes an electrode plate for a plasma processing apparatus and a focusing ring. The electrode plate for the plasma processing apparatus has ventilation holes through which a gas for generating plasma passes. The plasma processing apparatus is characterized in that at least one of the electrode plate for the plasma processing apparatus and the focusing ring has a heat conductive layer containing at least one of a fluororesin and a fluoroelastomer.

[0036] According to the plasma processing apparatus having this structure, since the heat conductive layer of at least one of the electrode plate for the plasma processing apparatus and the focusing ring contains at least one of a fluororesin and a fluoroelastomer, it has excellent heat resistance and plasma resistance, has high heat uniformity, and is less likely to cause contamination.

[0037] According to the above-described aspect of the present invention, there is provided a heat conductive material having excellent heat resistance and plasma resistance, and thus a component for a plasma processing apparatus having high heat uniformity over a long period of time and a method for manufacturing the same can be provided. Further, according to the present invention, a plasma processing apparatus in which contamination is less likely to occur can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. is a perspective view of an example of an electrode plate for a plasma processing apparatus according to the present embodiment.

[0039] Figure 2 is Figure 1 a cross-sectional view taken along line II-II of

[0040] Figure 3 FIG. is a schematic configuration diagram of an example of a plasma etching apparatus according to the present embodiment.

[0041] Figure 4 FIG. is a perspective view of an example of a focusing ring according to the present embodiment.

[0042] Figure 5 is Figure 4 a cross-sectional view taken along line V-V of

[0043] Figure 6 FIG. is a schematic configuration diagram of another example of a plasma etching apparatus according to the present embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] Hereinafter, a component for a plasma processing apparatus, a method for manufacturing the same, and a plasma processing apparatus according to an embodiment of the present invention will be described with appropriate reference to the drawings.

[0045] The plasma processing apparatus according to the present embodiment is, for example, a plasma processing apparatus such as a plasma etching apparatus or a plasma CVD apparatus used in a semiconductor device manufacturing process. The component for a plasma processing apparatus according to the present embodiment is a component used inside the plasma processing apparatus, and is, for example, an electrode plate for a plasma processing apparatus or a focusing ring. The electrode plate for a plasma processing apparatus according to the present embodiment is used, for example, as an upper electrode of a pair of electrodes provided in a vacuum chamber of a plasma processing apparatus, and the plasma processing apparatus is a plasma etching apparatus or a plasma CVD apparatus used in a semiconductor device manufacturing process. The focusing ring according to the present embodiment is, for example, a circular support ring that supports a workpiece disposed in a vacuum chamber of a plasma processing apparatus at its peripheral portion.

[0046] Figure 1 FIG. is a perspective view of an example of an electrode plate for a plasma processing apparatus according to the present embodiment, Figure 2 is Figure 1Cross-sectional view taken along line II-II

[0047] In Figure 1 and Figure 2 the electrode plate 10 for a plasma processing apparatus has a disc shape and is formed with a plurality of vent holes 11 through which a gas for plasma generation passes. The electrode plate 10 for a plasma processing apparatus has a substrate 12 and a heat conductive layer 13 formed on the surface of the substrate 12.

[0048] The diameter of the vent hole 11 can be, for example, in the range of 0.1 mm or more and 1 mm or less. The aspect ratio (thickness of the substrate 12 / diameter of the vent hole 11) of the vent hole 11 in the substrate 12 can be 1 or more, preferably 3 or more. Also, the aspect ratio of the vent hole 11 can be 200 or less.

[0049] Although the material constituting the substrate 12 is not particularly limited, Si (silicon) or SiC (silicon carbide) is preferred. The diameter of the substrate 12 can be, for example, in the range of 200 mm or more and 400 mm or less. The thickness of the substrate 12 can be, for example, in the range of 1 mm or more and 20 mm or less.

[0050] The heat conductive layer 13 contains at least one of a fluorine-based resin (fluororesin, fluorine-containing resin) and a fluorine-based elastomer (fluoroelastomer, fluorine-containing elastomer). The heat conductive layer 13 can contain a fluorine-based resin alone, can contain a fluorine-based elastomer alone, or can contain a mixture of a fluorine-based resin and a fluorine-based elastomer. The fluorine-based resin preferably has elasticity. The heat conductive layer 13 preferably contains a filler. The heat conductive layer 13 preferably has a structure in which at least one of a fluorine-based resin and a fluorine-based elastomer is used as a matrix binder and the filler is dispersed in the matrix binder.

[0051] The fluorine-based resin preferably has a fluorine-containing group in the main chain. The fluorine-based elastomer is preferably a fluorine-containing three-dimensionally crosslinkable compound having a fluorine-containing group and a three-dimensional crosslinked structure. As the fluorine-containing group, perfluoroalkylene -(CF2) x -(x is an integer of 1 or more) and perfluoropolyether group can be cited. As the perfluoropolyether group, for example, -(CF2CF2O) m (CF2O) n -(m, n are integers of 1 or more), -(CF2CF2CF2O) p -(p is an integer of 1 or more), -(CF2CF(CF3)O) q -(q is an integer of 1 or more), etc. can be cited. As the three-dimensional crosslinked structure, an organosilicon structure having a silicon-carbon bond, a silicone structure having a siloxane bond, an epoxy structure having an epoxy bond, a polyurethane structure having a polyurethane bond, etc. can be cited. One kind of fluorine-containing three-dimensionally crosslinkable compound can be used alone, or two or more kinds can be used in combination.

[0052] As the material for the filler, alumina (Al2O3), alumina hydrate, aluminum nitride (AlN), silicon dioxide (SiO2), silicon carbide (SiC), titanium dioxide (TiO2), boron nitride (BN), etc. can be used. Among these materials, alumina and boron nitride are preferred. The shape of the filler is not particularly limited, and for example, it can be spherical, flat, or fibrous. Alumina is more preferably α-alumina. Boron nitride is more preferably granular boron nitride.

[0053] The content of the filler in the heat-conducting layer 13 is preferably in the range of 50% by mass or more and 90% by mass or less. When the content of the filler is 50% by mass or more (the content of the matrix binder is less than 50%), the thermal conductivity of the heat-conducting layer 13 will be improved. When the content of the filler is 90% by mass or less (the content of the matrix binder is more than 10%), the sheet formability will be improved.

[0054] The thickness of the heat-conducting layer 13 is preferably in the range of 20 μm or more and 1 mm or less, and particularly preferably in the range of 20 μm or more and 500 μm or less.

[0055] Next, a method for manufacturing the electrode plate 10 for the plasma processing apparatus of the present embodiment will be described.

[0056] The electrode plate 10 for the plasma processing apparatus can be manufactured by a method including the following steps.

[0057] (1) Preparation step: Prepare a substrate 12 having a plurality of ventilation holes 11.

[0058] (2) Coating step: Coat a coating composition on one surface of the substrate 12 by heating or ultraviolet irradiation to form a coating layer. The coating composition contains a fluorine-based compound that generates at least one of a fluorine-based resin and a fluorine-based elastomer; and

[0059] (3) Heat-conducting layer formation step: Generate a heat-conducting layer 13 containing at least one of a fluorine-based resin and a fluorine-based elastomer by heating the coating layer or irradiating the coating layer with ultraviolet light.

[0060] In the preparation process, there is no particular limitation on the method of forming the vent holes 11 in the substrate 12. Various methods that can be used as the method of the vent holes 11 of the electrode plate 10 for the plasma processing device can be used. For example, a method of mechanically forming the vent holes 11 using a drill, a method of forming the vent holes 11 by heat using laser irradiation, etc. In the substrate 12 in which the vent holes 11 are formed, there are cases where burrs are generated around the vent holes and the flatness of the surface where the vent holes are not formed decreases. When there are burrs around the vent holes or the flatness of the surface where the vent holes are not formed decreases, it will become the main cause of coating unevenness in the next coating process. Therefore, with respect to the substrate 12 in which the vent holes 11 are formed, it is preferable to remove the burrs by etching treatment before performing the coating process, and then polish the upper and lower surfaces of the substrate 12 to improve the flatness.

[0061] The coating composition used in the coating process is preferably a composition containing a fluorine-based compound and a filler. The coating composition may further contain a fluorine-based oil and a volatile solvent.

[0062] The fluorine-based compound is a compound that generates a fluorine-based resin and / or a fluorine-based elastomer by heating or ultraviolet irradiation. The fluorine-based compound is preferably a fluorine-containing crosslinkable compound that generates a fluorine-containing three-dimensional crosslinkable compound by heating or ultraviolet irradiation. As the fluorine-containing crosslinkable compound, a fluorine-containing crosslinkable silicone compound, a fluorine-containing crosslinkable silicone ketone compound, a fluorine-containing rubber crosslinkable epoxy compound, and a fluorine-containing crosslinkable polyurethane compound can be used. As an example of a commercially available product of the fluorine-based compound, SHIN-ETSU SIFEL (registered trademark) manufactured by Shin-Etsu Chemical Co., Ltd. can be cited.

[0063] The fluorine-based oil functions as a viscosity modifier for the coating composition. The fluorine-based oil is preferably a liquid polymer having a perfluoropolyether group. Examples of the perfluoropolyether group are the same as those in the case of the above-mentioned fluorine-based resin and fluorine-based elastomer. The polymer of the fluorine-based oil may bond a linear or branched saturated or unsaturated hydrocarbon group, an aromatic group, or a hydrocarbon group containing a hetero atom to the perfluoropolyether group. As an example of a commercially available product of the fluorine-based oil, Fomblin (registered trademark) sold by Solvay, DEMNUM (registered trademark) sold by Daikin Industries, Ltd., Krytox (registered trademark) sold by Chemours, etc. can be cited. As an example of a commercially available product of the volatile solvent, Novec (registered trademark) sold by 3M can be cited.

[0064] In the coating process, as a method of coating the coating composition on one side of the substrate 12, the screen printing method is preferably used. And, before coating the coating composition, it is preferable to dispose a mask material in the vent holes 11 of the substrate 12. The mask material for screen printing may be a metal mask or a mesh mask. Also, instead of disposing a mask material in the vent holes 11 of the substrate 12, a mask patterned to block the vent holes 11 may be used.

[0065] In the heat conductive layer forming process, a heat conductive layer 13 containing at least one of a fluororesin and a fluoroelastomer is formed by heating the coating layer or irradiating the coating layer with ultraviolet rays. The heating temperature or the irradiation amount of ultraviolet rays is a condition for the fluorine compound to form a fluororesin and / or a fluoroelastomer.

[0066] Through the above processes, the electrode plate 10 for a plasma processing apparatus of the present embodiment is manufactured.

[0067] The electrode plate 10 for a plasma processing apparatus is used as an upper electrode in the vacuum chamber of the plasma processing apparatus. Figure 3 FIG. is a schematic structural diagram showing an example of a plasma etching apparatus using the electrode plate 10 for a plasma processing apparatus according to the present embodiment.

[0068] As Figure 3 shown, the plasma etching apparatus 100 has a vacuum chamber 30, an etching gas introduction part 1 disposed on the upper side in the vacuum chamber 30, and a workpiece support part 2 disposed on the lower side in the vacuum chamber 30. In the etching gas introduction part 1, the electrode plate 10 (upper electrode) for a plasma processing apparatus according to the present embodiment is provided such that the heat conductive layer 13 faces upward. And, in the workpiece support part 2, a stage (lower electrode) 20 that can move up and down is provided in parallel with the electrode plate 10 for a plasma processing apparatus with a space therebetween. At this time, the upper electrode plate 10 for a plasma processing apparatus is supported in an insulating state from the wall part of the vacuum chamber 30 by an insulator 14, and an electrostatic chuck 21 and a focusing ring (support ring) 22 made of Si (silicon) or SiC (silicon carbide) surrounding the electrostatic chuck 21 are provided on the stage 20. On the electrostatic chuck 21, a wafer (workpiece substrate) 40 is placed in a state of being supported by the focusing ring 22 at its peripheral part. And, it is configured as follows: an etching gas supply pipe 31 is provided on the upper side of the vacuum chamber 30, and the etching gas transported from the etching gas supply pipe 31 flows into the wafer 40 through the vent holes 11 provided in the electrode plate 10 for a plasma processing apparatus after passing through a diffusion member 32, and is discharged to the outside from a discharge port 33 on the side part of the vacuum chamber 30. On the other hand, a high-frequency voltage is applied between the electrode plate 10 for a plasma processing apparatus and the stage 20 by a high-frequency power supply 50.

[0069] A cooling plate 15 is fixed to the back of the electrode plate 10 for a plasma processing device via a heat conductive layer 13. Aluminum or the like having excellent thermal conductivity is used as a material of the cooling plate 15. Through holes 16 are also formed on the cooling plate 15 in a manner that is connected to the vent holes 11 of the electrode plate 10 for a plasma processing device and at the same pitch as the vent holes 11. The electrode plate 10 for a plasma processing device is fixed in the plasma etching device 100 by bolts or the like in a state where the back of the electrode plate 10 contacts the cooling plate 15.

[0070] The gas for plasma generation passes through the vent hole 11 from top to bottom (in the direction of the arrow), and plasma is generated below the electrode plate 10 for the plasma processing device. The heat generated together with the plasma is conducted from the base material 12 of the electrode plate 10 for the plasma processing device to the cooling plate 15 via the heat conductive layer 13, and is dissipated to the outside.

[0071] Next, the focus ring according to this embodiment will be described.

[0072] Figure 4 is a perspective view of an example of a focus ring according to this embodiment. Figure 5 for Figure 4 VV line profile.

[0073] exist Figure 4 and Figure 5 In the embodiment, the focus ring 22 includes an annular base material 23 with a circular central opening and a heat conductive layer 24. The annular base material 23 includes an annular flat portion 23a and a protrusion 23b formed on the outer peripheral side of one surface of the flat portion 23a. The heat conductive layer 24 is provided on the surface of the annular base material 23 opposite to the surface on which the protrusion 23b is formed.

[0074] The diameter of the annular substrate 23 can be, for example, in the range of 350 mm to 500 mm. The central opening diameter of the annular substrate 23 can be in the range of 295 mm to 298 mm. In addition, the thickness of the protrusion 23b of the annular substrate 23 can be, for example, in the range of 2 mm to 8 mm. The thickness of the flat portion 23a of the annular substrate 23 can be in the range of 0.5 mm to 7.5 mm. The material constituting the annular substrate 23 is not particularly limited, but is preferably Si (silicon) or SiC (silicon carbide). In addition, the flat portion 23a of the annular substrate 23 may not be a complete circle.

[0075] The heat-conductive layer 24 contains at least one of a fluororesin and a fluoroelastomer. The heat-conductive layer 24 preferably contains a filler. Examples of the fluororesin, fluoroelastomer, and filler contained in the heat-conductive layer 24 are the same as those of the electrode plate 10 for the plasma processing apparatus described above. Also, similar to the case of the electrode plate 10 for the plasma processing apparatus described above, the thickness of the heat-conductive layer 24 is preferably in the range of 20 μm or more and 1 mm or less, and particularly preferably in the range of 20 μm or more and 500 μm or less.

[0076] The focusing ring 22 can be manufactured by a method including the following steps.

[0077] (1) Preparation step: Prepare an annular substrate 23 having an annular flat portion 23a and a protrusion portion 23b formed on the outer peripheral side of one surface of the flat portion 23a.

[0078] (2) Coating step: On the surface of the annular substrate 23 opposite to the surface on which the protrusion portion 23b is formed, a coating layer is formed by coating a coating composition by heating or ultraviolet irradiation. The coating composition contains a fluorine compound that generates at least one of a fluororesin and a fluoroelastomer.

[0079] (3) Heat-conductive layer formation step: A heat-conductive layer 24 containing at least one of a fluororesin and a fluoroelastomer is generated by heating the coating layer or irradiating the coating layer with ultraviolet light.

[0080] In the preparation step, there is no particular limitation on the method of forming the annular substrate 23. For example, a method of mechanically processing into an annular shape using a drill can be used. Also, as the annular substrate 23, an annular substrate formed by annularly bonding a plurality of arc-shaped members in the circumferential direction can be used. A focusing ring having a structure formed by bonding the plurality of arc-shaped members is described in Japanese Unexamined Patent Application Publication No. 2011-3730. In the focusing ring of this structure, as the adhesive for bonding the plurality of arc-shaped members, the above-mentioned fluororesin and / or fluoroelastomer can be used.

[0081] There are no particular limitations on the coating method of the coating composition in the coating step and the generation method of the heat-conductive layer 24 in the heat-conductive layer formation step. For example, the same method as that of the electrode plate 10 for the plasma processing apparatus described above can be used.

[0082] Figure 6 It is a schematic structural diagram showing another example of the plasma etching apparatus according to the present embodiment. Figure 6 The shown plasma etching apparatus 200, except for using the above-mentioned annular substrate 23 and heat-conductive layer 24 as the focusing ring 22, is the same as Figure 3 the shown plasma etching apparatus 100. Therefore, in Figure 6 the shown plasma etching apparatus 200, similar toFigure 3 Parts common to the plasma etching apparatus 100 shown are denoted by the same reference numerals, and detailed description thereof is omitted.

[0083] In Figure 6 In the plasma etching apparatus 200 shown, the object to be processed support section 2 includes a stage 20, an electrostatic chuck 21, a focus ring 22, and a heat sink 25.

[0084] The stage 20 is circular in plan view. The focus ring 22 is disposed on the outer peripheral portion of the stage 20. The focus ring 22 supports the peripheral edge portion of the wafer 40 by a circular base material 23. The heat sink 25 is disposed at the central portion of the stage 20, and the electrostatic chuck 21 is disposed on the heat sink 25. A refrigerant flow path 27 is provided inside the stage 20, and the stage 20 also functions as a cooling section. Further, the stage 20 is connected to a ground plate 28 and also functions as an electrode section. The electrostatic chuck 21 can be connected to a high-frequency power source (not shown).

[0085] An O-ring 26 is disposed between the stage 20 and the focus ring 22. The O-ring 26 is disposed in a circular shape in plan view. As the material of the O-ring 26, a heat-resistant elastomer such as silicone rubber or a fluorine-based elastomer can be used. An intermediate layer can be provided between the stage 20 and the focus ring 22. The intermediate layer can be a sintered body of ceramics such as alumina, yttrium oxide, silicon carbide, aluminum nitride, or silicon nitride.

[0086] According to the components for a plasma processing apparatus (the electrode plate 10 for a plasma processing apparatus, the focus ring 22) of the present embodiment having the above-described structure, since the heat conductive layer contains at least one of a fluorine-based resin and a fluorine-based elastomer, the heat resistance and the plasma resistance are excellent. Therefore, the components for a plasma processing apparatus have high heat uniformity for a long time and are less likely to cause contamination.

[0087] In the components for a plasma processing apparatus of the present embodiment, when the material forming the base material (the base material 12, the circular base material 23) is Si or SiC, the thermal conductivity of the base material is improved. Therefore, the heat uniformity of the components for a plasma processing apparatus is improved.

[0088] In the component for a plasma processing apparatus according to the present embodiment, when the heat conductive layers 13 and 24 contain a filler, the thermal conductivity of the heat conductive layer is improved. Therefore, the heat uniformity of the component for a plasma processing apparatus is further improved. Moreover, when the filler is at least one of alumina and / or boron nitride, the thermal conductivity of the heat conductive layers 13 and 24 is further reliably improved. Therefore, the heat uniformity of the component for a plasma processing apparatus is further improved. Further, in the component for a plasma processing apparatus according to the present embodiment, when the fluororesin and the fluorine-based elastomer are compounds having a perfluoropolyether group, the heat resistance and plasma resistance of the heat conductive layers 13 and 24 are further improved. Therefore, the component for a plasma processing apparatus will further have high heat uniformity for a long time and is less likely to cause contamination. Further, in the component for a plasma processing apparatus according to the present embodiment, when the thickness of the heat conductive layers 13 and 24 is in the range of 20 μm or more and 1 mm or less, the heat conductive layers 13 and 24 can be easily brought into close contact with the cooling plate 15 or the stage 20 of the plasma processing apparatus, thereby improving the thermal conductivity between the heat conductive layer 13 and the cooling plate 15 or between the heat conductive layer 24 and the stage 20. Further, since the thickness of the heat conductive layers 13 and 24 is 1 mm or less, the thermal conductivity of the heat conductive layers 13 and 24 is also high. Therefore, the heat uniformity of the component for a plasma processing apparatus is further improved.

[0089] The component for a plasma processing apparatus according to the present embodiment may be an electrode plate 10 for a plasma processing apparatus having a vent hole 11 through which a gas for plasma generation passes. At this time, the electrode plate 10 for a plasma processing apparatus may have the following structure: a substrate 12 is a substrate having a plurality of vent holes 11, and a heat conductive layer 13 is provided on one surface of the substrate 12. Further, it may also have the following structure: the substrate 12 is in a disc shape, the thickness is in the range of 1 mm or more and 20 mm or less, the diameter of the vent hole 11 is in the range of 0.1 mm or more and 1 mm or less, and the aspect ratio of the vent hole 11 is 1 or more, preferably 3 or more. At this time, since the electrode plate 10 for a plasma processing apparatus has high close contact property with the cooling plate 15 of the plasma etching apparatus 100, has high heat uniformity for a long time, and is less likely to cause contamination, plasma processing can be stably performed for a long time.

[0090] The component for a plasma processing apparatus according to the present embodiment may be a focusing ring 22. At this time, the focusing ring 22 may have the following structure: a base material is an annular base material 23 having an annular flat portion 23a and a protrusion portion 23b formed on the outer peripheral side of one surface of the flat portion 23a, and a heat conductive layer 24 is provided on the surface of the flat portion 23a opposite to the surface on which the protrusion portion 23b is formed. At this time, since the focusing ring 22 has high close contact property with the stage 20 of the plasma etching apparatus 200, has high heat uniformity for a long time, and is less likely to cause contamination, plasma processing can be stably performed for a long time.

[0091] In the manufacturing method of the component for a plasma processing apparatus according to the present embodiment, a heat conductive layer is formed by coating a coating composition on a substrate preformed into a specific shape. Therefore, various shaped components for a plasma processing apparatus, such as the electrode plate 10 or the focusing ring 22 for a plasma processing apparatus, can be effectively manufactured. Moreover, the contact between the heat conductive layer and the substrate is good, and the thermal resistance can be reduced. Further, regarding the obtained component for a plasma processing apparatus, since the heat conductive layer contains at least one of a fluororesin and a fluoroelastomer, it has excellent heat resistance and plasma resistance, has high heat uniformity for a long time, and is less likely to cause contamination.

[0092] In the manufacturing method of the component for a plasma processing apparatus according to the present embodiment, the substrate can be a substrate 12 having a plurality of ventilation holes 11, and the coating composition is coated on one surface of the substrate 12. At this time, since the heat conductive layer 13 is formed on the substrate 12 having a plurality of ventilation holes 11, it is easy to align the positions of the ventilation holes 11 of the substrate 12 and the ventilation holes 11 of the heat conductive layer 13. Therefore, the electrode plate 10 for a plasma processing apparatus having the ventilation holes 11 can be effectively manufactured. Further, as a manufacturing method of the electrode plate 10 for a plasma processing apparatus, a method of separately manufacturing a heat conductive material (heat conductive layer) having a plurality of ventilation holes 11 and placing the heat conductive material on the substrate can be considered. At this time, positional deviation is likely to occur when the heat conductive material is placed on the substrate. Therefore, although the ventilation holes of the heat conductive material need to be set to a size capable of absorbing the positional deviation, at this time, the contact surface between the cooling plate and the heat conductive plate of the plasma processing apparatus and the contact area between the heat conductive material and the substrate become smaller, and heat cannot be effectively transferred. Moreover, when forming ventilation holes in an independent heat conductive material, if the number of ventilation holes in the heat conductive material is large, the mechanical strength of the heat conductive material itself becomes weak, and it is difficult to handle it as an independent heat conductive material. In particular, since the mechanical strength of the heat conductive material itself is further weakened when the filler filling amount is large, the filler filling amount cannot be increased. In contrast, according to the above manufacturing method, since there is no need to separately separate the heat conductive layer, a heat conductive layer with a large filler filling amount can be formed. Therefore, by the above manufacturing method, the electrode plate 10 for a plasma processing apparatus having heat uniformity and thermal stability can be manufactured.

[0093] In the manufacturing method of the electrode plate for a plasma processing apparatus according to the present embodiment, when the substrate is an annular substrate 23 having an annular flat portion 23a and a protrusion portion 23b formed on the outer peripheral side of one surface of the flat portion 23a, and the coating composition is coated on the surface of the flat portion 23a opposite to the surface on which the protrusion portion 23b is formed, the focusing ring 22 can be effectively manufactured.

[0094] In the plasma etching apparatuses 100 and 200 according to the present embodiment, since at least one of the heat conductive layers 13 and 24 of the electrode plate 10 for the plasma processing apparatus and the focus ring 22 contains at least one of a fluorine-based resin and a fluorine-based elastomer, the heat resistance and plasma resistance are excellent, the heat uniformity is high, and contamination is less likely to occur.

[0095] As described above, embodiments of the present invention have been described, but the present invention is not limited thereto, and appropriate modifications can be made without departing from the technical idea of the present invention. For example, although Figure 6 in the plasma etching apparatus 200 of the described embodiment, the heat conductive layer 13 of the electrode plate 10 for the plasma processing apparatus and the heat conductive layer 24 of the focus ring 22 are structured such that at least one of them contains at least one of a fluorine-based resin and a fluorine-based elastomer, if the heat conductive layer 24 of the focus ring 22 is structured to contain at least one of a fluorine-based resin and a fluorine-based elastomer, the heat conductive layer 13 of the electrode plate 10 for the plasma processing apparatus may not contain a fluorine-based resin and a fluorine-based elastomer.

[0096] Examples

[0097] [Example 1 of the Present Invention]

[0098] (1) Preparation of the coating composition

[0099] 8.7 parts by mass of a rubber agent I (X-71-6053-6A, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether group and having thermosetting properties, 9.0 parts by mass of a rubber agent II (X-71-6053-6B, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether group and having thermosetting properties, 57.2 parts by mass of a large particle size alumina filler (AA-18, manufactured by Sumitomo Chemical Co., Ltd., average particle size (d50): 18 μm), and 25.1 parts by mass of a small particle size alumina filler (AA-3, manufactured by Sumitomo Chemical Co., Ltd., average particle size (d50): 3 μm) (content of the heat conductive filler: 82.3 mass%) were mixed. The obtained mixture was degassed and kneaded using a rotation-revolution vacuum mixer (Defoaming Ren Tarou ARV-310, manufactured by THINKY Corporation) to prepare the coating composition.

[0100] (2) Fabrication of the electrode plate substrate for the plasma processing apparatus

[0101] Vent holes were formed on the Si substrate using a drill. Then, after removing the burrs around the vent holes generated on the upper and lower surfaces of the Si substrate by etching, the upper and lower surfaces of the Si substrate were polished to fabricate the electrode plate substrate for the plasma processing apparatus.

[0102] (3) Fabrication of the electrode plate for the plasma processing apparatus

[0103] A mask material is disposed in the ventilation holes on one side of the electrode substrate for a plasma processing apparatus fabricated in the above (2). Next, on the surface of the electrode for the plasma processing apparatus, using a metal mask provided with an opening having the same diameter as the diameter of the electrode substrate for the plasma processing apparatus, the coating composition prepared in the above (1) is applied by screen printing to form a coating layer with a thickness of 0.3 mm after heating. The electrode substrate for the plasma processing apparatus having the coating layer formed thereon is put into a heating furnace and heated at 150 °C for 30 hours. Then, the electrode substrate for the plasma processing apparatus is taken out from the heating furnace, cooled to room temperature, and after confirming that the coating layer has hardened to form a heat conduction layer, the mask material is removed. In this way, an electrode for a plasma processing apparatus is fabricated.

[0104] (4) Evaluation

[0105] (Thickness of the heat conduction layer of the electrode for a plasma processing apparatus)

[0106] The electrode for the plasma processing apparatus after the formation of the heat conduction layer is cut, and the film thickness is determined from the SEM photograph of the cross section. As a result, it is confirmed that the average thickness of the heat conduction layer is 0.3 mm.

[0107] (Rate of decrease in radical irradiation)

[0108] Under the rich O2 condition and the rich CF4 condition carried out, the rate of decrease in radical irradiation after radical irradiation of the heat conduction layer of the electrode for the plasma processing apparatus is calculated according to the following formula. Among them, the rich O2 condition is: using O2 and CF4 as reaction gases, setting their flow rates to 500 ml / min and 10 ml / min respectively, setting the reaction pressure to 40 Pa, and setting the radical irradiation time to 1 hour; the rich CF4 condition is: using O2 and CF4 as reaction gases, setting their flow rates to 100 ml / min and 410 ml / min respectively, setting the reaction pressure to 100 Pa, and setting the radical irradiation time to 1 hour. As a result, the rate of decrease in radical irradiation is 0% by mass under either the rich O2 condition or the rich CF4 condition.

[0109] Rate of decrease in radical irradiation (% by mass) = [(mass before irradiation - mass after irradiation) / mass before irradiation] × 100 (where the mass before irradiation is the mass of the electrode for the plasma processing apparatus before radical irradiation, and the mass after irradiation is the mass of the electrode for the plasma processing apparatus after radical irradiation).

[0110] (Rate of loss on heating)

[0111] For the electrode plate for a plasma processing apparatus, the heating loss rate after heating in air at 240°C for 5 hours is calculated according to the following formula. Also, the heating loss rate after heating in air at 240°C for 75 hours is calculated in the same way. As a result, the heating loss rate when heated at 240°C for 5 hours is 0.8 mass%, and the heating loss rate when heated at 240°C for 75 hours is 3.2 mass%.

[0112] Heating loss rate (mass%) = [(mass before heating - mass after heating) / mass before heating] × 100

[0113] (wherein, the mass before heating is the mass of the electrode plate for the plasma processing apparatus before heating, and the mass after heating is the mass of the electrode plate for the plasma processing apparatus after heating.)

[0114] [Example 2 of the present invention]

[0115] Prepare a circular substrate made of Si having an annular flat portion and a protrusion portion formed on the outer peripheral side of one surface of the flat portion. By the screen printing method, the coating composition prepared in (1) of Example 1 of the present invention is coated on the surface of the circular substrate opposite to the surface on which the protrusion portion is formed, and a coating layer having a thickness of 0.3 mm after heating is formed. The circular substrate having the coating layer formed thereon is put into a heating furnace and heated at 150°C for 30 hours. Then, the circular substrate is taken out from the heating furnace and cooled to room temperature, and it is confirmed that the coating layer is hardened and a heat conductive layer is formed. In this way, a focusing ring for a plasma processing apparatus is manufactured.

[0116] For the obtained focusing ring for a plasma processing apparatus, in the same manner as in Example 1 of the present invention, the thickness of the heat conductive layer, the free radical irradiation loss rate, and the heating loss rate are measured. As a result, the thickness of the heat conductive layer is 0.3 mm, the free radical irradiation loss rate is 0 mass%, the heating loss rate when heated at 240°C for 5 hours is 0.8 mass%, and the heating loss rate when heated at 240°C for 75 hours is 3.2 mass%.

[0117] Industrial applicability

[0118] According to the present invention, it is possible to provide a component for a plasma processing apparatus having a heat conductive material with excellent heat resistance and plasma resistance and having high heat uniformity for a long time, and a manufacturing method thereof. Moreover, according to the present invention, it is possible to provide a plasma processing apparatus that is less likely to cause contamination.

[0119] Symbol description

[0120] 1 Etching gas introduction part

[0121] 2 Object to be processed support part

[0122] 10 Electrode plate for plasma processing apparatus

[0123] 11 Vent hole

[0124] 12 Base material

[0125] 13 Heat conduction layer

[0126] 14 Insulator

[0127] 15 Cooling plate

[0128] 20 Stand (lower electrode)

[0129] 21 Electrostatic chuck

[0130] 22 Focusing ring

[0131] 23 Annular base material

[0132] 23a Flat part

[0133] 23b Protruding part

[0134] 24 Heat conduction layer

[0135] 25 Heat dissipation plate

[0136] 26 O-ring

[0137] 27 Refrigerant flow path

[0138] 28 Grounding plate

[0139] 30 Vacuum chamber

[0140] 31 Etching gas supply pipe

[0141] 32 Diffusion component

[0142] 33 Outlet

[0143] 40 Wafer (substrate to be processed)

[0144] 50 High-frequency power supply

[0145] 100, 200 Plasma etching device

Claims

1. A component for a plasma processing apparatus, characterized in that it has a substrate and a heat conductive layer provided on one surface of the substrate, the heat conductive layer contains at least one of a fluororesin and a fluoroelastomer and a filler, the filler is one or more selected from alumina, aluminum hydrate, aluminum nitride, silica, silicon carbide, titanium oxide, and boron nitride, the content of the filler in the heat conductive layer is in the range of 50% by mass or more and 90% by mass or less, the component for the plasma processing apparatus is a focusing ring.

2. The component for the plasma processing apparatus according to claim 1, wherein the material forming the substrate is Si or SiC.

3. The component for the plasma processing apparatus according to claim 1 or 2, wherein the filler is at least one of alumina and boron nitride.

4. The component for the plasma processing apparatus according to claim 1 or 2, wherein the fluororesin and the fluoroelastomer are compounds having a perfluoropolyether group.

5. The component for the plasma processing apparatus according to claim 1 or 2, wherein the thickness of the heat conductive layer is in the range of 20 μm or more and 1 mm or less.

6. The component for the plasma processing apparatus according to claim 1 or 2, wherein the substrate of the focusing ring is a circular substrate having a circular flat portion and a protrusion portion formed on the outer peripheral side of one surface of the flat portion, and the heat conductive layer is provided on the surface of the flat portion opposite to the surface on which the protrusion portion is formed.

7. A manufacturing method of a component for a plasma processing apparatus, wherein, The component for the plasma processing apparatus is a focusing ring, and the manufacturing method of the component for the plasma processing apparatus includes: a preparation step of preparing a substrate; a coating step of forming a coating layer by coating a coating composition on one surface of the substrate by heating or ultraviolet irradiation, the coating composition containing a fluorine compound that generates at least one of a fluororesin and a fluoroelastomer and a filler; and a heat conductive layer forming step of generating a heat conductive layer containing at least one of a fluororesin and a fluoroelastomer by heating the coating layer or irradiating the coating layer with ultraviolet light, the filler is one or more selected from alumina, aluminum hydrate, aluminum nitride, silica, silicon carbide, titanium oxide, and boron nitride, the content of the filler in the heat conductive layer is in the range of 50% by mass or more and 90% by mass or less.

8. The manufacturing method of the component for the plasma processing apparatus according to claim 7, wherein the substrate is a circular substrate having a circular flat portion and a protrusion portion formed on the outer peripheral side of one surface of the flat portion, the coating composition is coated on the surface of the flat portion opposite to the surface on which the protrusion portion is formed.

9. A plasma processing apparatus includes a plasma processing apparatus electrode plate and a focusing ring. The plasma processing apparatus electrode plate has a ventilation hole through which a gas for plasma generation passes. The plasma processing apparatus is characterized in that the focusing ring or both the plasma processing apparatus electrode plate and the focusing ring have a heat conductive layer, The heat-conducting layer contains at least one of a fluororesin and a fluoroelastomer and a filler, The filler is one or more selected from alumina, aluminum hydrate, aluminum nitride, silicon dioxide, silicon carbide, titanium oxide, and boron nitride, The content of the filler in the heat-conducting layer is in the range of 50% by mass or more and 90% by mass or less.

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