JP7552173B2 - Resin composition, liquid resin composition, method for producing liquid resin composition, etching device and reaction vessel - Google Patents

Description

The present invention relates to a resin composition, a liquid resin composition, a method for producing a liquid resin composition, an etching device, and a reaction vessel.

As an etching apparatus for etching a workpiece such as a silicon wafer or a glass substrate, an apparatus that uses fluorine radicals generated by turning a fluorine-containing gas into plasma to etch the workpiece is known. In this etching apparatus, it is necessary to prevent the etching conditions from fluctuating due to the heat generated by turning the fluorine-containing gas into plasma. It is also necessary to prevent the inside of the reaction vessel from being deteriorated by the fluorine radicals.

In order to suppress fluctuations in etching processing conditions due to heat, it has been considered to place a heat transfer sheet with high thermal conductivity between a circular ring-shaped member (focus ring) that protects the periphery of the workpiece and a support stand that supports the focus ring (Patent Document 1). As the heat transfer sheet, a resin composition containing a resin component and a filler component has been considered.

In addition, in order to prevent deterioration of the inside of the reaction vessel due to fluorine radicals, it has been considered to coat the gas supply plate for supplying fluorine-containing gas and the inner surface of the reaction vessel with a plasma-resistant thermal spray film (Patent Document 2).

JP 2012-9563 A JP 2016-28379 A

When a heat transfer sheet is placed between the focus ring and its support stand, the resin component of the heat transfer sheet may deteriorate due to heat or fluorine radicals, exposing the filler component to the outside and causing it to detach from the resin component as fine particles. In addition, when the inner surface of the reaction vessel is covered with a thermal sprayed film, part of the thermal sprayed film may deteriorate due to fluorine radicals and cause it to detach as fine particles. If the particles are scattered inside the reaction vessel, they may adhere to the surface of the workpiece and contaminate the workpiece. This makes it difficult to etch the workpiece stably over a long period of time.

The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a resin composition that has excellent heat resistance and fluorine radical resistance, has high thermal conductivity, and is less likely to generate particles when used in an etching device that generates fluorine radicals. Another aim of the present invention is to provide a liquid resin composition that can be advantageously used as a raw material for the above-mentioned resin composition, and a method for producing the liquid resin composition. A further aim of the present invention is to provide an etching device that can stably etch a workpiece over a long period of time, and a reaction vessel for use in the etching device.

In order to solve the above problems, the resin composition of the present invention contains at least one of a fluorine-based resin and a fluorine-based elastomer, and silicon powder, and is for an etching device that generates fluorine radicals, and the silicon powder has an average particle size in the range of 0.1 μm or more and 400 μm or less (excluding 100 nm) .

According to the resin composition of this configuration, since the resin component contains at least one of a fluorine-based resin and a fluorine-based elastomer, the heat resistance and plasma resistance are improved. In addition, since the resin composition of this configuration contains silicon powder, the thermal conductivity is high. Furthermore, the silicon powder reacts with fluorine radicals to generate SiF ₄ (silicon tetrafluoride) gas. Therefore, when the resin component of the resin composition of the above configuration is deteriorated by heat or fluorine radicals and the silicon powder is exposed to the outside, the exposed silicon powder can be discharged to the outside of the reaction vessel as SiF ₄ gas. Therefore, the resin composition of the above configuration is less likely to generate particles when used in an etching device that generates fluorine radicals.

In the resin composition of the present invention, the silicon powder preferably has an average particle size in the range of 0.1 μm or more and 400 μm or less.
In this case, the silicon powder has an average particle size of 0.1 μm or more, a large surface area, and improved adhesion to the resin component, so that even when the silicon powder is exposed to the outside due to deterioration of the resin component, it is difficult to detach from the resin component. Also, since the silicon powder has an average particle size of 400 μm or less, the silicon powder exposed to the outside due to deterioration of the resin component is likely to react with fluorine radicals and is easily released to the outside of the reaction vessel as SiF ₄ gas. Therefore, particles are unlikely to be generated.

In the resin composition of the present invention, the silicon powder preferably has at least two peaks in a particle size distribution within the particle diameter range of 0.1 μm or more and 400 μm or less.
In this case, since the silicon powder has a wide particle size distribution, silicon particles having a relatively small particle size can be interposed between silicon particles having a relatively large particle size, and the content of silicon powder in the resin composition can be increased. By increasing the content of silicon powder, it is possible to further increase the thermal conductivity of the resin composition.

Furthermore, in the resin composition of the present invention, the content of the silicon powder relative to the total amount of at least one of the fluororesin and the fluoroelastomer and the silicon powder is preferably within the range of 30% by volume or more and 90% by volume or less.
In this case, since the content of silicon powder is 30% by volume or more, the thermal conductivity of the resin composition can be more reliably increased. Also, since the content of silicon powder is 90% by volume or less and the content of resin component is 10% by volume or more, the shape stability and the applicability are improved.

The liquid resin composition of the present invention contains a liquid fluorine-based compound that produces at least one of a fluorine-based resin and a fluorine-based elastomer upon heating or exposure to ultraviolet light, and silicon powder, and is for use in an etching apparatus in which fluorine radicals are generated.
The liquid resin composition of this configuration contains a liquid fluorine-based compound that generates at least one of a fluorine-based resin and a fluorine-based elastomer by heating or irradiation with ultraviolet light, and therefore can be uniformly applied to curved surfaces or surfaces having irregularities, such as the inner wall surface of a reaction vessel. Thus, by using the liquid resin composition of this configuration, the aforementioned resin composition can be formed in various locations.

The method for producing the liquid resin composition of the present invention includes the steps of: pulverizing crystalline silicon lumps to obtain silicon powder; and mixing the silicon powder with a liquid fluorine-based compound that produces at least one of a fluorine-based resin and a fluorine-based elastomer by heating or irradiating with ultraviolet light.
According to the method for producing a liquid resin composition having this configuration, silicon powder is obtained by crushing crystalline silicon lumps, so that high-purity silicon powder with few impurities that are a source of particle generation can be used. Therefore, by using the liquid resin composition obtained by the production method having this configuration, a resin composition with stable properties such as heat resistance, fluorine radical resistance, and thermal conductivity can be obtained.

In the method for producing a liquid resin composition of the present invention, the crystalline silicon chunks are preferably recovered materials recovered in a production process of a crystalline silicon product.
In this case, since silicon powder is obtained using material that has not been used in the manufacturing process of crystalline silicon products and has been recovered, high-purity silicon powder can be obtained relatively inexpensively.

The reaction vessel of the present invention is for use in an etching apparatus in which fluorine radicals are generated, and at least a portion of the inner surface is coated with the above-mentioned resin composition.
According to the reaction vessel having this configuration, since the inner surface is coated with the above-mentioned resin composition, the heat resistance and fluorine plasma resistance are improved, and the generation of particles due to deterioration of the resin composition is suppressed. Therefore, by using the reaction vessel having this configuration, the object to be treated can be etched stably for a long period of time.

The etching apparatus of the present invention is an etching apparatus that generates fluorine radicals and includes a focus ring and a support base that supports the focus ring, and the above-mentioned resin composition is disposed at least partially between the focus ring and the support base.
In an etching apparatus having this configuration, the resin composition is disposed between the focus ring and the support stage, improving thermal conductivity between the focus ring and the support stage and reducing the occurrence of particles due to deterioration of the resin composition, so that the etching apparatus having this configuration can stably etch the workpiece for a long period of time.

According to the present invention, it is possible to provide a resin composition that has excellent heat resistance and fluorine radical resistance, has high thermal conductivity, and is less likely to generate particles when used in an etching device that generates fluorine radicals. In addition, according to the present invention, it is also possible to provide a liquid resin composition that can be advantageously used as a raw material for the above-mentioned resin composition, and a method for producing the liquid resin composition. Furthermore, according to the present invention, it is also possible to provide an etching device that can stably etch a target object over a long period of time, and a reaction vessel for use in the etching device.

1 is a cross-sectional view of an etching apparatus according to an embodiment of the present invention. 2 is an enlarged cross-sectional view of a processing object support portion of the etching apparatus of FIG. 1 .

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A resin composition, a liquid resin composition, a method for producing a liquid resin composition, an etching apparatus, and a reaction vessel according to embodiments of the present invention will be described below with reference to the accompanying drawings.
The etching apparatus according to the present embodiment is used, for example, in a semiconductor device manufacturing process, and is an apparatus that performs an etching process using fluorine radicals. The reaction vessel according to the present embodiment is a reaction vessel of the etching apparatus. The resin composition and liquid resin composition according to the present embodiment are used in the etching apparatus.

The resin composition according to the present embodiment contains at least one of a fluorine-based resin (fluorine resin, fluorine-containing resin) and a fluorine-based elastomer (fluorine elastomer, fluorine-containing elastomer) as a resin component, and contains silicon powder as a filler component. The resin component may contain a fluorine-based resin alone, a fluorine-based elastomer alone, or a mixture of a fluorine-based resin and a fluorine-based elastomer. The fluorine-based resin preferably has elasticity. The resin composition preferably has a configuration in which a fluorine-based resin and/or a fluorine-based elastomer is used as a matrix binder, and silicon powder is dispersed in the matrix binder.

The fluorine-based resin preferably has a fluorine-containing group in the main chain. The fluorine-based elastomer is preferably a fluorine-containing three-dimensional crosslinking compound having a fluorine-containing group and a three-dimensional crosslinking structure. Examples of the fluorine-containing group include a perfluoroalkylene group -(CF ₂ ) _x - (x is an integer of 1 or more) and a perfluoropolyether group. Examples of the perfluoropolyether group include -(CF ₂ CF ₂ O) _m (CF ₂ O) _n - (m and n are integers of 1 or more), -(CF ₂ CF ₂ CF ₂ O) _p - (p is an integer of 1 or more), and -(CF ₂ CF(CF ₃ )O) _q - (q is an integer of 1 or more). Examples of the three-dimensional crosslinking structure include an organosilicon structure having a silicon-carbon bond, a silicone structure having a siloxane bond, an epoxy structure having an epoxy bond, and a urethane structure having a urethane bond. The fluorine-containing three-dimensional cross-linking compound may be used alone or in combination of two or more kinds.

The silicon powder is preferably of high purity. The purity of the silicon powder is preferably 99.99% by mass or more, more preferably 99.9999% by mass or more, and particularly preferably 99.999999% by mass or more. High purity silicon powder can prevent contamination inside the etching device.

The silicon powder may be a single crystal or a polycrystal. The shape of the silicon powder is not particularly limited, and may be, for example, spherical, elliptical, cylindrical, prismatic, flat, or fibrous. The shape of the silicon powder may be amorphous. When the silicon powder is spherical, it is preferable that the sphericity is high. The silicon powder may have an average particle size in the range of 0.1 μm to 400 μm. Furthermore, the silicon powder may have at least two peaks in the particle size distribution in the range of 0.1 μm to 400 μm. The particle size distribution of the silicon particles may be a value measured using a laser diffraction particle size distribution device. The dispersion of silicon particles for particle size distribution measurement may be prepared, for example, by putting silicon particles together with a dispersant into an N-methyl-2-pyrrolidone (NMP) solvent and dispersing the silicon particles by ultrasonic dispersion.

The content of silicon powder in the resin composition is preferably in the range of 30% to 90% by volume, calculated as the content of silicon powder relative to the total amount of the resin components (fluorine-based resin and/or fluorine-based elastomer) and silicon powder. The content of silicon powder is more preferably in the range of 40% to 80% by volume.

The resin composition may have a reinforcing material added thereto. Examples of the reinforcing material include silica (SiO ₂ ), alumina (Al ₂ O ₃ ), alumina hydrate, aluminum nitride (AlN), silicon carbide (SiC), titanium oxide (TiO ₂ ), boron nitride (BN), and carbon. The shape of the reinforcing material is not particularly limited, and may be, for example, spherical, elliptical, cylindrical, prismatic, flat, or fibrous. The shape of the reinforcing material may also be amorphous. The content of the reinforcing material may be in the range of 0.1% by mass to 50% by mass, particularly 0.1% by mass to 10% by mass, based on the resin. The addition of the reinforcing material can improve the tensile strength of the resin composition.

The resin composition may be in the form of a sheet.
The sheet-like resin composition can be formed, for example, by applying a liquid fluorine-based compound described below onto a substrate, and then heating the resulting coating layer or irradiating the coating layer with ultraviolet light.

The resin composition of this embodiment is for use in an etching device that generates fluorine radicals, and is used inside the etching processing device. The resin composition can be used, for example, as a protective material for the inner surface of a reaction vessel of the etching processing device. In addition, the resin composition can be used, for example, as a heat transfer material that improves thermal conductivity between parts or an adhesive that improves bonding between parts by being placed between parts of an introduction part that introduces an etching gas into the reaction vessel of the etching processing device and parts of a support part that supports the material to be processed.

According to the resin composition of the present embodiment configured as described above, since the resin component contains at least one of a fluorine-based resin and a fluorine-based elastomer, heat resistance and plasma resistance are improved. In addition, since the resin composition of the present embodiment contains silicon powder, thermal conductivity is increased. Furthermore, silicon powder easily reacts with fluorine radicals to generate SiF ₄ gas. Therefore, when the resin component of the resin composition of the present embodiment is deteriorated by heat or fluorine radicals and the silicon powder is exposed to the outside, the exposed silicon powder can be discharged to the outside of the reaction vessel as SiF ₄ gas. Therefore, the resin composition of the present embodiment is less likely to generate particles when used in an etching device that generates fluorine radicals.

In the resin composition of this embodiment, when the average particle size of the silicon powder is 0.1 μm or more, the silicon powder has a large surface area and improves adhesion with the resin component, so that even when the silicon powder is exposed to the outside due to deterioration of the resin component, it is difficult to be detached from the resin component. Also, when the average particle size of the silicon powder is 400 μm or less, the silicon powder exposed to the outside due to deterioration of the resin component is easy to react with fluorine radicals and is easy to be released to the outside of the reaction vessel as SiF ₄ gas. Therefore, particles are unlikely to be generated.

In addition, in the resin composition of this embodiment, when the silicon powder has at least two peaks in the particle size distribution in the range of particle diameters of 0.1 μm or more and 400 μm or less, the silicon powder has a wide particle size distribution, so that silicon particles with relatively small particle diameters can be interposed between silicon particles with relatively large particle diameters, and the content of silicon powder in the resin composition can be increased. By increasing the content of silicon powder, it is possible to further increase the thermal conductivity of the resin composition.

Furthermore, in the resin composition of this embodiment, if the content of silicon powder relative to the total amount of the resin component and silicon powder is 30% by volume or more, the thermal conductivity of the resin composition can be more reliably increased. Also, if the content of silicon powder is 90% by volume or more, the content of the resin component is 10% by volume or more, which improves shape stability and applicability.

The liquid resin composition according to this embodiment can be advantageously used as a raw material for resin compositions. The liquid resin composition according to this embodiment contains a liquid fluorine-based compound that produces at least one of a fluorine-based resin and a fluorine-based elastomer by heating or irradiation with ultraviolet light, and silicon powder.

The liquid fluorine-based compound is preferably a fluorine-containing crosslinkable compound that generates a fluorine-containing three-dimensional crosslinkable compound by heating or irradiation with ultraviolet light. Examples of the fluorine-containing crosslinkable compound that can be used include fluorine-containing crosslinkable organosilicon compounds, fluorine-containing crosslinkable silicone compounds, fluorine-containing crosslinkable epoxy compounds, and fluorine-containing crosslinkable urethane compounds. An example of a commercially available fluorine-based compound is SHIN-ETSU SIFEL (registered trademark) manufactured by Shin-Etsu Chemical Co., Ltd.

The silicon powder contained in the liquid resin composition is the same as the silicon powder contained in the resin composition described above. In addition, the content of silicon powder contained in the liquid resin composition is preferably in the range of 30% by volume or more and 90% by volume or less, as the content of silicon powder relative to the total amount of the resin component and silicon powder generated by heating or irradiation with ultraviolet light.

The liquid resin composition may further contain a reinforcing material, a fluorine-based oil, and a volatile solvent. Examples of the reinforcing material are the same as those in the resin composition described above. The fluorine-based oil acts as a viscosity adjuster for the liquid resin 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 fluorine-based resin and fluorine-based elastomer described above. The polymer of the fluorine-based oil may have a perfluoropolyether group to which a linear or branched saturated or unsaturated hydrocarbon group, an aromatic group, or a hydrocarbon group containing a heteroatom is bonded. Examples of commercially available fluorine-based oils include Fomblin (registered trademark) sold by Solvay, Demnum (registered trademark) sold by Daikin Industries, Ltd., and Krytox (registered trademark) sold by Chemours. Examples of commercially available volatile solvents include Novec (registered trademark) sold by 3M.

The liquid resin composition can be produced, for example, by a method including a step of preparing a silicon powder and a step of mixing.
The silicon powder production process is a process of crushing crystalline silicon chunks to obtain silicon powder. As the crystalline silicon chunks, crushed crystalline silicon products such as silicon wafers and solar cell substrates, and crushed recovered materials collected in the manufacturing process of the crystalline silicon products can be used. Examples of recovered materials collected in the manufacturing process of crystalline silicon products include non-standard crystalline silicon products and small pieces generated by cutting and crushing performed during the manufacture of crystalline silicon products. In addition, the Siemens method is known as a method for manufacturing large polycrystalline silicon rods used as raw materials for manufacturing crystalline silicon products (see, for example, International Publication No. 2018/164197). The removed portion of the polycrystalline silicon rod obtained by the Siemens method may be collected and used as the above-mentioned recovered material. As a method for crushing crystalline silicon chunks to obtain silicon powder, for example, a method of crushing the crystalline silicon chunks using a coarse crusher such as a jaw crusher, and finely pulverizing the obtained coarsely crushed material using a ball mill can be used. The obtained silicon powder may be adjusted in particle size using a classification device such as a sieve.

The mixing step is a step of mixing the above-mentioned silicon powder with a liquid fluorine-based compound that produces at least one of a fluorine-based resin and a fluorine-based elastomer by heating or irradiation with ultraviolet light. There are no particular limitations on the method of mixing the liquid fluorine-based compound with the silicon powder, and various methods that are industrially used as a method of mixing a resin component and a filler component can be used.

The liquid resin composition of this embodiment, which has the above-mentioned configuration, contains a liquid fluorine-based compound that produces at least one of a fluorine-based resin and a fluorine-based elastomer when heated or irradiated with ultraviolet light, so it can be applied evenly to curved surfaces or surfaces with irregularities, such as the inner wall surface of a reaction vessel. Therefore, by using the liquid resin composition of this configuration, the resin composition of this embodiment can be formed in various locations.

In addition, according to the manufacturing method of the liquid resin composition of this embodiment, silicon powder is obtained by crushing crystalline silicon lumps, so that high-purity silicon powder with few impurities that are a source of particle generation can be used. Therefore, by using the liquid resin composition obtained by the manufacturing method of this configuration, a resin composition with stable properties such as heat resistance, fluorine radical resistance, and thermal conductivity can be obtained. Furthermore, in the manufacturing method of the liquid resin composition of this embodiment, high-purity silicon powder can be obtained relatively inexpensively by using, as the crystalline silicon lumps, recovered materials that were not used in the manufacturing process of crystalline silicon products.

The etching apparatus of this embodiment is an apparatus that etches a processing target such as a semiconductor wafer or a glass substrate by using fluorine radicals.
FIG. 1 is a cross-sectional view of an etching apparatus according to an embodiment of the present invention.
As shown in FIG. 1, the etching apparatus 100 includes a reaction vessel 10 , an etching gas inlet 20 , and a processing target support 30 .

The reaction vessel 10 includes a gate valve 11 and an exhaust port 12 .
The gate valve 11 is an opening that can be opened and closed for inserting and removing the workpiece 50 into and from the reaction vessel 10. The exhaust port 12 is an opening for exhausting the reaction gas 52 generated inside the reaction vessel 10 to the outside. The inner surface of the reaction vessel 10 is covered with a protective material 13. In the etching apparatus 100 shown in FIG. 1, the inner surface of the side of the reaction vessel 10 is covered with a protective material 13. The above-mentioned resin composition is used as the material of the protective material 13. The protective material 13 can be formed, for example, by applying the above-mentioned liquid resin composition to the inner surface of the reaction vessel 10, heating the resulting coating layer or irradiating the coating layer with ultraviolet light to generate at least one of a fluorine-based resin and a fluorine-based elastomer, and curing the coating layer.

The etching gas introduction section 20 is fixed to the upper part of the reaction vessel 10 via an insulating member 15. The etching gas introduction section 20 includes a gas introduction substrate 21, a cooling plate 24, and an electrode plate 25. The gas introduction substrate 21 has a gas introduction section 22 at the upper part and an electrode fixing section 23 at the lower part. The electrode plate 25 is fixed to the electrode fixing section 23 of the gas introduction substrate via the cooling plate 24. The electrode fixing section 23, the cooling plate 24, and the electrode plate 25 have a large number of ventilation holes 26 penetrating in the thickness direction, and the gas introduced from the gas introduction section 22 is supplied below the electrode plate 25 through the ventilation holes 26. The electrode plate 25 is connected to a high-frequency power source 41.

The workpiece support part 30 is disposed at a position facing the electrode plate 25 of the etching gas inlet part 20. The workpiece support part 30 includes a support table 31, a focus ring 33, an electrostatic chuck 34, and a heat extraction plate 35.
The support table 31 has a circular shape in a plan view. A focus ring 33 is disposed on the outer periphery of the support table 31. A heat extraction plate 35 is disposed in the center of the support table 31, and an electrostatic chuck 34 is disposed on the heat extraction plate 35. The support table 31 has a second coolant flow path 32 therein and also functions as a cooling section. The support table 31 is also connected to an earth 42 and also functions as an electrode section. The electrostatic chuck 34 is connected to a high-frequency power supply (not shown).

Between the support base 31 and the focus ring 33, an O-ring 36 and a first heat transfer material 37 are arranged. The O-ring 36 is arranged on the inside. The first heat transfer material 37 is arranged on the outside of the O-ring 36 in a circular ring shape in a plan view. The material of the O-ring 36 can be, for example, a heat-resistant elastic body such as silicone rubber or a fluorine-based elastomer. The material of the first heat transfer material 37 is the above-mentioned resin composition. The first heat transfer material 37 can be formed, for example, by applying the above-mentioned liquid resin composition in a circular ring shape on the support base 31 and curing the resulting coating layer by heating the coating layer or irradiating the coating layer with ultraviolet light. An intermediate layer may be provided at least one between the support base 31 and the first heat transfer material 37 and between the focus ring 33 and the first heat transfer material 37. The intermediate layer may be a sintered ceramic such as alumina, yttria, silicon carbide, aluminum nitride, or silicon nitride. The focus ring 33 may also be formed by bonding multiple arc-shaped members together in a ring shape in the circumferential direction. A focus ring formed by bonding multiple arc-shaped members together is described in JP 2011-3730 A. In a focus ring of this configuration, the aforementioned resin composition may be used as the adhesive for bonding the multiple arc-shaped members together.

A second heat transfer material 38 is disposed between the electrostatic chuck 34 and the heat extraction plate 35. The aforementioned resin composition is used as the material of the second heat transfer material 38. The second heat transfer material 38 can be formed, for example, by applying the aforementioned liquid resin composition onto the heat extraction plate 35 and curing the resulting coating layer by heating the coating layer or irradiating the coating layer with ultraviolet light.

The workpiece 50 is placed on the electrostatic chuck 34. The focus ring 33 of the workpiece 50 protects the periphery of the workpiece 50. The workpiece 50 is, for example, a semiconductor wafer or a glass substrate.

The etching process of the object to be processed 50 by the etching apparatus 100 is performed as follows.
First, the gate valve 11 of the reaction vessel 10 is opened, and the workpiece 50 is placed on the electrostatic chuck 34 through the gate valve 11. Next, after closing the gate valve 11, an etching gas 51 is introduced into the reaction vessel 10 through the gas introduction part 22 of the etching gas introduction part 20. As the etching gas, for example, a mixed gas of CF ₄ (tetrafluoromethane) gas and O ₂ (oxygen) gas can be used. The etching gas 51 introduced into the reaction vessel 10 is supplied to the space between the electrode plate 25 and the workpiece 50 through the electrode fixing part 23, the cooling plate 24, and the vent hole 26 provided in the electrode plate 25.

Next, a high-frequency voltage is applied between the electrode plate 25 and the support table 31 using the high-frequency power supply 41. This excites the etching gas supplied between the electrode plate 25 and the workpiece 50, generating plasma containing fluorine radicals and heat. The workpiece 50 is etched by the fluorine radicals of the plasma, generating SiF ₄ gas. The reaction gas 52 containing SiF ₄ gas is exhausted to the outside of the reaction vessel 10 through the exhaust port 12. The heat transferred to the electrode plate 25 is transferred to the gas introduction substrate 21 through the cooling plate 24. The heat transferred to the gas introduction substrate 21 is dissipated to the outside. On the other hand, the heat transferred to the workpiece 50 is transferred to the support table 31 through the focus ring 33 and the first heat transfer material 37, or through the electrostatic chuck 34, the second heat transfer material 38, and the heat extraction plate 35. The heat transferred to the support table 31 is dissipated to the outside of the reaction vessel 10 by the coolant flowing through the second coolant flow path 32.

According to the etching apparatus 100 of the present embodiment configured as described above, the inner surface of the reaction vessel 10 is covered with the protective material 13 using the resin composition of the present embodiment, so that the heat resistance and fluorine plasma resistance are improved and the generation of particles due to deterioration of the protective material 13 is less likely to occur. In addition, since the first heat transfer material 37 containing the resin composition of the present embodiment is arranged between the focus ring 33 and the support base 31, the thermal conductivity between the focus ring 33 and the support base 31 is improved and the generation of particles due to deterioration of the first heat transfer material 37 is less likely to occur. Furthermore, since the second heat transfer material 38 containing the resin composition of the present embodiment is arranged between the electrostatic chuck 34 and the heat extraction plate 35, the thermal conductivity between the electrostatic chuck 34 and the heat extraction plate 35 is improved and the generation of particles due to deterioration of the second heat transfer material 38 is less likely to occur. Therefore, according to the etching apparatus 100 of the present embodiment, the processing target 50 can be etched stably for a long period of time.

Although the embodiment of the present invention has been described above, the present invention is not limited to this, and can be modified as appropriate within the scope of the technical idea of the invention. For example, in the etching apparatus 100 of this embodiment, the inner surface of the reaction vessel 10 is covered with the protective material 13, the first heat transfer material 37 is arranged between the focus ring 33 and the support base 31, and the second heat transfer material 38 is arranged between the electrostatic chuck 34 and the heat extraction plate 35, but the present invention is not limited to this. For example, depending on the material and shape of the reaction vessel 10, it may be configured not to be covered with the protective material 13. In addition, it may be configured to arrange the first heat transfer material 37 between the focus ring 33 and the support base 31, and not arrange the second heat transfer material 38 between the electrostatic chuck 34 and the heat extraction plate 35, or it may be configured to arrange the second heat transfer material 38 between the electrostatic chuck 34 and the heat extraction plate 35, and not arrange the first heat transfer material 37 between the focus ring 33 and the support base 31. In addition, in the etching apparatus 100 of this embodiment, only the inner surface of the side of the reaction vessel 10 is covered with the protective material 13, but the present invention is not limited to this. For example, the entire inner surface of the reaction vessel 10 may be covered with a resin composition.

[Example 1]
A liquid fluorine-based compound was prepared by mixing 8.7 parts by mass of a gel-based elastomer I (X-71-6053-6A, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether group and thermal crosslinking property and 9.0 parts by mass of a gel-based elastomer II (X-71-6053-6B, manufactured by Shin-Etsu Chemical Co., Ltd.) having a perfluoropolyether group and thermal crosslinking property. The liquid fluorine-based compound obtained was mixed with silicon powder in such a ratio that the amount of silicon powder was 60% by volume relative to the total volume of the resin component and silicon powder produced by heating. The obtained mixture was kneaded while defoaming using a rotary/revolution vacuum mixer (Awatori Rentaro ARV-310, manufactured by Thinky Corporation) to prepare a liquid resin composition.

The silicon powder used was made by crushing polycrystalline silicon lumps. The polycrystalline silicon lumps were obtained by cutting a porous silicon rod made by the Siemens method using a carbon electrode at a position 30 mm from the end of the carbon electrode and recovering it. The silicon powder was made by roughly crushing the porous silicon lumps using a jaw crusher, then pulverizing them using a ball mill, and then classifying them. The particle size distribution of the obtained silicon powder was measured using a laser diffraction particle size distribution measuring device, and the average particle size was 40 μm, the particle size of the first peak was 18 μm, and the particle size of the second peak was 50 μm.

[Examples 2 to 5 of the present invention]
A liquid resin composition was prepared in the same manner as in Example 1 of the present invention, except that the liquid fluorine-based compound and the silicon powder were mixed in such a ratio that the amount of silicon powder relative to the total volume of the resin component and the silicon powder produced by heating would give the filler content shown in Table 1 below.

[Example 6]
A liquid resin composition was prepared in the same manner as in Example 1 of the present invention, except that a perfluoropolyether group-containing, thermally crosslinkable elastomer (X-71-359, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the resin component.

[Comparative Example 1]
A liquid resin composition was prepared in the same manner as in Example 1 of the present invention, except that an alumina powder (average particle size: 50 μm, no two or more peaks in the particle size distribution) was used instead of the silicon powder.

[Comparative Example 2]
A liquid resin composition was prepared in the same manner as in Example 1 of the present invention, except that silicone rubber (KE-1950-10A and KE-1950-10B, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the resin component.

[evaluation]
For the liquid resin compositions obtained in Examples 1 to 6 of the present invention and Comparative Examples 1 and 2, the presence or absence of particle generation due to exposure to fluorine radicals, the amount of mass loss due to exposure to fluorine radicals, and the thermal conductivity were measured by the following methods.

(Measurement of particle generation)
A liquid resin composition is applied onto a stainless steel substrate (50 mm x 50 mm), and the resulting coating layer is subjected to primary and secondary vulcanization to form a 10 mm x 10 mm square resin composition layer with a thickness of 0.3 mm, thereby producing a stainless steel substrate with a resin composition layer. The resulting stainless steel substrate with a resin composition layer is placed in a plasma generator so that the resin composition layer faces upward. While supplying _CF4 gas and _O2 gas into the plasma generator at a volume ratio of 1:2 so that the total pressure is 100 Pa, fluorine radicals are generated for 60 seconds using a 1500 W microwave, and then the operation of stopping the generation of fluorine radicals for 60 seconds is repeated 30 times, and the surface of the resin composition layer is exposed to fluorine plasma for a total of 30 minutes. After exposure, the stainless steel substrate with a resin composition layer is removed from the plasma generator, and a conductive carbon tape is attached to the surface of the stainless steel substrate with a resin composition layer, and then immediately peeled off. The adhesive surface of the peeled conductive carbon tape is observed in an area of 600 μm × 400 μm using a SEM (scanning electron microscope), and the number of filler components (particles) with a particle diameter of 0.1 μm or more attached to the adhesive surface is counted. The number of particles is counted at five locations, and the average number is calculated. If the average number of particles is 300 or less, it is marked as "◯", if it is more than 300 and 3000 or less, it is marked as "△", and if it is more than 3000, it is marked as "X".

(Measurement of mass loss)
In the same manner as in the measurement of particle generation, a stainless steel substrate with a resin composition layer is prepared, and the surface of the resin composition layer of the stainless steel substrate with a resin composition layer is exposed to fluorine plasma for a total of 30 minutes. The mass loss due to exposure to fluorine radicals by fluorine plasma is calculated using the following formula.
Mass reduction amount [mass%] = (X-Y)/X x 100
In the above formula, X represents the mass of the stainless steel substrate with a resin composition layer before exposure to fluorine plasma, and Y represents the mass of the stainless steel substrate with a resin composition layer after exposure to fluorine plasma.

(Measurement of thermal conductivity)
The thermal conductivity is measured by a steady-state method. A stainless steel substrate with a resin composition layer is prepared in the same manner as in the case of particle generation. However, by changing the amount of liquid resin composition applied onto the stainless steel substrate, a plurality of stainless steel substrates with resin composition layers having different thicknesses of 150 μm, 250 μm, and 400 μm are prepared. The thermal resistance R of the resin composition layer is measured for each of the obtained plurality of stainless steel substrates with resin composition layers. The regression coefficient is calculated using the least squares method with R×100 ^mm2 as the dependent variable and the thickness of the resin composition layer as the independent variable. The reciprocal of the obtained regression coefficient is taken as the thermal conductivity.

The resin compositions of Examples 1 to 6 of the present invention, which contain at least one of a fluorine-based resin and a fluorine-based elastomer as a resin component and silicon powder as a filler component, generated fewer particles due to exposure to fluorine radicals compared to the resin composition of Comparative Example 1. In addition, the resin compositions of Examples 1 to 6 of the present invention showed less mass loss due to exposure to fluorine radicals compared to the resin composition of Comparative Example 2. In particular, the resin compositions of Examples 1 to 4 and 6 of the present invention, which contain 80 mass% or less of silicon powder, showed less mass loss due to exposure to fluorine radicals. In addition, the thermal conductivity of the resin composition increased with an increase in the content of silicon powder.

The reason why the resin compositions of Examples 1 to 6 of the present invention generated few particles is that the silicon powder exposed to the outside due to the deterioration of the resin component caused by exposure to fluorine radicals reacted with the fluorine radicals and disappeared as _SiF4 gas. In contrast, the reason why the resin composition of Comparative Example 1 using alumina powder as the filler component generated many particles is that since alumina powder has excellent resistance to fluorine radicals, the alumina powder exposed to the outside due to the deterioration of the resin component caused by exposure to fluorine radicals did not disappear but remained in large quantities, and this exposed alumina powder adhered to the adhesive surface of the adhesive tape.

The reason why the mass loss was small in the resin compositions of Inventive Examples 1 to 6 is because the fluororesin and fluoroelastomer have excellent fluorine radical resistance. In contrast, the mass loss due to exposure to fluorine radicals was large in the resin composition of Comparative Example 2, which used silicone rubber as the resin component. This is because the silicone resin has poor fluorine radical resistance, and therefore a large amount of the resin component was decomposed and lost due to exposure to fluorine radicals, and the silicon powder exposed to the outside reacted with the fluorine radicals and lost as _SiF4 gas.

REFERENCE SIGNS LIST 10 Reaction vessel 11 Gate valve 12 Exhaust port 13 Protective material 15 Insulating member 20 Etching gas inlet 21 Gas inlet substrate 22 Gas inlet 23 Electrode fixing portion 24 Cooling plate 25 Electrode plate 26 Vent 30 Workpiece support 31 Support table 32 Second coolant passage 33 Focus ring 34 Electrostatic chuck 35 Heat extraction plate 36 O-ring 37 First heat transfer material 38 Second heat transfer material 41 High frequency power supply 42 Earth 50 Workpiece 51 Etching gas 52 Reactive gas 100 Etching device

Claims (8)

The composition contains at least one of a fluorine-based resin and a fluorine-based elastomer, and silicon powder, and is for use in an etching device that generates fluorine radicals;
A resin composition , wherein the silicon powder has an average particle size in the range of 0.1 μm or more and 400 μm or less (excluding 100 nm) . The resin composition according to claim 1 , wherein the silicon powder has at least two peaks in a particle size distribution within a particle diameter range of 0.1 μm or more and 400 μm or less. 3. The resin composition according to claim 1, wherein a content of the silicon powder relative to a total amount of the at least one of the fluororesin and the fluoroelastomer and the silicon powder is in a range of 30% by volume to 90% by volume. A liquid resin composition for use in an etching device that generates fluorine radicals, comprising a liquid fluorine-based compound that produces at least one of a fluorine-based resin and a fluorine-based elastomer upon heating or exposure to ultraviolet light, and silicon powder. grinding the crystalline silicon chunks to obtain silicon powder;
5. The method for producing a liquid resin composition according to claim 4 , further comprising a step of mixing the silicon powder with a liquid fluorine-based compound which produces at least one of a fluorine-based resin and a fluorine-based elastomer by heating or irradiating with ultraviolet light. The method for producing a liquid resin composition according to claim 5 , wherein the crystalline silicon chunks are recovered during a process for producing a crystalline silicon product. For an etching apparatus in which fluorine radicals are generated,
A reaction vessel, at least a portion of the inner surface of which is coated with the resin composition according to any one of claims 1 to 3 . An etching apparatus for generating fluorine radicals, comprising: a focus ring; and a support base for supporting the focus ring,
4. An etching apparatus, comprising: a resin composition according to claim 1 disposed at least partially between the focus ring and the support base.

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