WO2013141070A1 - Air filter for cvd apparatus, and cvd apparatus having same - Google Patents

Air filter for cvd apparatus, and cvd apparatus having same Download PDF

Info

Publication number
WO2013141070A1
WO2013141070A1 PCT/JP2013/056731 JP2013056731W WO2013141070A1 WO 2013141070 A1 WO2013141070 A1 WO 2013141070A1 JP 2013056731 W JP2013056731 W JP 2013056731W WO 2013141070 A1 WO2013141070 A1 WO 2013141070A1
Authority
WO
WIPO (PCT)
Prior art keywords
cvd apparatus
air filter
filter medium
medium layer
filter
Prior art date
Application number
PCT/JP2013/056731
Other languages
French (fr)
Japanese (ja)
Inventor
和明 辻
善宏 瀬戸口
学 本居
大 佐藤
Original Assignee
日本バルカー工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日本バルカー工業株式会社 filed Critical 日本バルカー工業株式会社
Publication of WO2013141070A1 publication Critical patent/WO2013141070A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D39/00—Filtering material for liquid or gaseous fluids
    • B01D39/14—Other self-supporting filtering material ; Other filtering material
    • B01D39/16—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres
    • B01D39/1607—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous
    • B01D39/1623—Other self-supporting filtering material ; Other filtering material of organic material, e.g. synthetic fibres the material being fibrous of synthetic origin
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/44—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the method of coating
    • C23C16/4401—Means for minimising impurities, e.g. dust, moisture or residual gas, in the reaction chamber
    • C23C16/4402—Reduction of impurities in the source gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2239/00—Aspects relating to filtering material for liquid or gaseous fluids
    • B01D2239/12—Special parameters characterising the filtering material
    • B01D2239/1233—Fibre diameter

Definitions

  • the present invention relates to an air filter used in a CVD apparatus (air filter for CVD apparatus) and a CVD apparatus having the same.
  • the air filter is used to collect (capture) fine particles contained in air, source gas or exhaust gas, and has a high particle capture rate (capability of collecting particles with high efficiency) and pressure loss. Low is required.
  • the materials that make up the air filter also vary widely depending on the application.
  • Fluorine resin such as polytetrafluoroethylene (PTFE) is known as a material constituting the air filter. Since fluororesins have excellent properties (chemical resistance, plasma resistance, heat resistance, etc.), fluororesin air filters are used in a wide range of applications.
  • PTFE polytetrafluoroethylene
  • Patent Document 1 discloses a turbine air inlet filter including a composite filter medium and a frame.
  • the composite filter medium includes a membrane filter layer containing porous polytetrafluoroethylene (expanded PTFE) and a depth filter medium layer. Comprising.
  • Patent Document 2 discloses a filter medium including a PTFE porous membrane (stretched PTFE) obtained by stretching unsintered PTFE under specific conditions.
  • Patent Document 3 an PTFE powder is dispersed in a matrix (e.g., viscose) to prepare an aqueous dispersion, and the aqueous dispersion is discharged into a coagulation bath and spun to produce an unstretched PTFE fiber sheet.
  • a fluorine fiber thin sheet used for filter applications is disclosed, which is produced by heating and sintering an unstretched PTFE fiber sheet and stretching it at least in the longitudinal direction or the transverse direction.
  • Patent Document 4 a raw material for paper making of a fluoro fiber is dehydrated and dried by a wet paper making method using a wire netting die to form a forming raw material, and the forming raw material is subjected to the heat treatment after the forming raw material.
  • a fluorine fiber molded article used for a filter which is obtained by inserting the preform into a mold and hot pressing.
  • Such a filter made of a fluorine fiber cannot balance pressure loss and particle trapping in a well-balanced manner, and there is still room for improvement in filter performance.
  • the chemical vapor deposition (CVD: Chemical Vapor Deposition) method supplies a raw material gas containing the desired thin film components onto the substrate material into the CVD apparatus, and deposits the thin film by chemical reaction on the substrate surface or in the gas phase. It is a method to do. For example, it is generally used in the surface treatment of cutting tools and the manufacturing process of semiconductor elements. Further, the types of CVD are various such as thermal CVD and plasma CVD according to the formation mechanism of the thin film.
  • the filter installed at the exhaust port of the CVD apparatus is required to have a high particle capture rate. Furthermore, since the inside of the CVD apparatus is in a high temperature atmosphere (for example, thermal CVD) or the source gas is excited to a plasma state (for example, plasma CVD), it is used in the CVD apparatus. Such a filter is also required to have heat resistance and plasma resistance (radical resistance).
  • the present invention exhibits characteristics suitable for use in an air filter for a CVD apparatus, such as a well-balanced filter performance such as low pressure loss and high particle capture rate, and excellent heat resistance and plasma resistance.
  • An object of the present invention is to provide an air filter for a CVD apparatus and a CVD apparatus having the same.
  • the present inventors have found that when a filter medium layer containing PTFE fibers having a specific average fiber diameter is used as an air filter material, the pressure loss is low and the particle trapping rate is high. It has been found that it exhibits performance and is excellent in heat resistance and plasma resistance. And the present inventors completed this invention based on being able to exhibit the characteristic suitable as such an air filter for CVD apparatuses.
  • the gist of the present invention is as follows.
  • An air filter for a CVD apparatus having a filter medium layer (a) containing PTFE fiber (a), wherein the PTFE fiber (a) has an average fiber diameter of 10 nm to 50 ⁇ m. Air filter for CVD equipment.
  • a CVD apparatus wherein the air filter for a CVD apparatus according to any one of [1] to [5] is installed at a source gas supply port and / or a gas exhaust port.
  • FIG. 1 is a view showing an electron micrograph obtained in Example 3 before using the actual machine.
  • FIG. 2 is an electron micrograph obtained after using the actual machine (surface) obtained in Example 3.
  • FIG. 3 is a view showing an electron micrograph of the actual machine obtained in Example 3 after use (back side).
  • the air filter for a CVD apparatus has, as an essential component, a polytetrafluoroethylene fiber (a) (PTFE) having an average fiber diameter of 10 nm to 50 ⁇ m.
  • PTFE polytetrafluoroethylene fiber
  • a filter medium layer (a) comprising fibers (a)), and a support layer (b) is laminated on one side or both sides of the filter medium layer (a) as necessary, as will be described later. Also good.
  • the air filter of the present invention is in a state where the source gas and / or the exhaust gas can be filtered into a CVD (chemical vapor deposition) apparatus (specifically, the source gas supply port and / or the exhaust gas discharge port of the apparatus). And collect the particles (dust, dust) contained in the raw material gas and / or exhaust gas by filtering the raw material gas supplied into the device and / or the exhaust gas exhausted from inside the device ( Used to capture).
  • the air filter of the present invention exhibits excellent air filter performance such as high heat resistance and high radical resistance (plasma resistance) as well as well-balanced air filter performance such as low pressure loss and high particle capture rate.
  • CVD apparatus can be used for various types of CVD apparatuses regardless of the type of deposition and the mechanism of vapor deposition on the substrate.
  • the CVD apparatus include a thermal CVD apparatus, a plasma CVD apparatus, a photo CVD apparatus, and a MOCVD (metalorgano-CVD) apparatus.
  • the average fiber diameter of the PTFE fiber (a) is 10 nm to 50 ⁇ m, preferably 100 nm to 5000 nm.
  • the pressure loss can be reduced and the air trapping performance can be improved, for example, the particle capture rate can be improved.
  • the average fiber diameter of the PTFE fiber (a) is a region that is randomly observed by a scanning electron microscope (SEM) for the PTFE fiber (a) to be measured, and this region is then observed by SEM. (Magnification: 10,000 times) 10 PTFE fibers (a) were selected at random, the fiber diameters of the 10 selected PTFE fibers (a) were measured, and the obtained 10 fiber diameter values. Is an arithmetic average value calculated based on SEM.
  • the PTFE fiber (a) when the PTFE fiber (a) is obtained by an electrospinning method, the PTFE concentration in the spinning solution, the atmospheric humidity during production, the tip diameter of the spinning nozzle, the applied voltage, the voltage density, etc. are appropriately adjusted. By doing so, PTFE fiber (a) having a desired average fiber diameter can be obtained.
  • the electrospinning method the PTFE fiber (a) is obtained by using a spinning solution having a low PTFE concentration, lowering the atmospheric humidity, reducing the tip diameter of the spinning nozzle, increasing the applied voltage, or increasing the voltage density. The average fiber diameter tends to be small.
  • PTFE fiber (a) is a fiber containing PTFE in a content of usually 95 to 100% by weight, preferably 99 to 100% by weight, more preferably 100% by weight.
  • the air filter for a CVD apparatus according to the present invention can exhibit plasma resistance (radical resistance), heat resistance (particularly low heat shrinkage), and the like due to the characteristics of the PTFE fiber (a).
  • the method for producing PTFE fiber (a) is not particularly limited as long as it is a method for producing PTFE fiber having an average fiber diameter in the above range, but is obtained by electrospinning (electrostatic spinning) method. Is preferred.
  • the electrospinning method can easily obtain the PTFE fiber (a) having an average fiber diameter in the above range, and when the PTFE fiber (a) obtained by such a method is used for the air filter in the present invention, An air filter having a high particle trapping rate, low pressure loss, and high durability against heat, radicals and harmful substances can be realized.
  • electrospinning method for example, from the spinning solution containing the above-mentioned PTFE and a solvent, and optionally additives (fiber forming agent, ionic surfactant, viscosity modifier, etc.), for example, US 2010/0193999 A1.
  • a known electrospinning method such as the method described in Japanese Patent Publication No. 1993-2011 can be used.
  • the porosity (porosity) of the filter medium layer (a) is preferably 0.60 to 0.95 from the viewpoint of securing a fluid flow path for preventing an increase in pressure loss and securing the filter medium strength. More preferably, it is 0.70 to 0.90.
  • the basis weight of the filter medium layer (a) depends on the fiber diameter of the PTFE fiber, it is preferably 1 to 200 g / m 2 from the viewpoint of achieving both high particle capturing performance and low pressure loss and ensuring the filter medium strength. More preferably, it is 10 to 100 g / m 2 .
  • the thickness of the filter medium layer (a) depends on the fiber diameter of the PTFE fiber, it is preferably 5 ⁇ m to 200 ⁇ m from the viewpoint of achieving both high particle capturing performance and low pressure loss.
  • the porosity, basis weight, and thickness in the filter medium layer (a) are increased by increasing the spinning time or increasing the number of spinning nozzles when preparing the PTFE fiber (a) using the electrospinning method. Tend to.
  • the manufacturing method of the air filter for CVD apparatus which concerns on this invention is not specifically limited,
  • the process of manufacturing PTFE fiber (a) by the above-mentioned electrospinning method, and said PTFE fiber (a) in a sheet form It includes a step of accumulating to form an air filter.
  • the filter medium layer (a) may be formed by collecting the PTFE fibers (a) in a sheet shape and forming them). Good).
  • the air filter according to the present invention may be a filter medium layer (a) that is not laminated with a support layer (b) or the like (single-layer air filter), and may further include a filter medium layer.
  • the support layer (b) or the like laminated air filter
  • the laminated air filter includes, for example, a step of producing PTFE fibers (a) having a specific average fiber diameter as described above, and PTFE fibers (a) on at least one surface of the support layer (b). It can produce by implementing the process of accumulating in a sheet form and forming a filter medium layer (a). These two steps may be performed separately or simultaneously (that is, PTFE fibers (a) are accumulated in a sheet form on at least one surface of the support layer (b) while being produced).
  • the filter medium layer (a) may be formed).
  • a support body layer (b) the conventionally well-known support body layer in an air filter can be used, for example, the mesh comprised from iron, copper, stainless steel etc., for example, glass fiber, a cellulose fiber, polyolefin fiber, nylon Nonwoven fabrics composed of fibers, polyester fibers and the like can be mentioned.
  • a support body layer (b) consists of a nonwoven fabric comprised from the mesh or glass fiber comprised from iron, copper, stainless steel, etc.
  • the air filter of the present invention has at least one filter medium layer (c) made of a material different from the filter medium layer (a) in addition to the filter medium layer (a) comprising PTFE fibers (a). It may be.
  • the air filter of the present invention may be composed of a filter medium layer (a) and one or more filter medium layers (c), and further laminated with one or more support layers (b). It may be a thing. In order to prevent clogging of the filter medium layer, it is preferable to collect dust for each particle diameter by a plurality of filter medium layers from the viewpoint of maintaining long-term performance of the air filter.
  • the filter medium layer (c) is preferably metallic from the viewpoint of durability, and is a powder filter medium made of a sintered metal powder, a mesh filter medium made of a sintered metal wire mesh, a wool and a nonwoven cloth made of metal fibers. Conventionally known materials such as filter media can be used.
  • the air filter of the present invention may be subjected to conventionally known processing within a range not impairing its performance, for example, may be subjected to pleating.
  • PTFE fiber (a) 1 consisting only of PTFE was produced by an existing electrospinning method. The properties of the produced PTFE fiber (a) 1 were measured or evaluated based on the following “measurement method / evaluation criteria”. The obtained results are shown in Table 1.
  • PTFE fiber (a) 1 was deposited (superposed) to produce a filter medium layer (a) 1 (length 10 cm, width 10 cm).
  • the characteristics of the produced filter medium layer (a) 1 were measured or evaluated based on the following “measurement method / evaluation criteria”. The obtained results are shown in Table 1.
  • Thickness of the filter medium layer (a) 1 The thickness of the filter medium layer (a) 1 was measured by LITEMATAC VL-50 (manufactured by Mitutoyo Corporation).
  • the basis weight (g / m 2 ) of the filter medium layer (a) 1 of the filter medium layer (a) 1 was measured according to JIS L 1906 (2000).
  • the porosity filter medium layer (a) 1 was cut into a 4 cm square (4 cm long ⁇ 4 cm wide) to prepare a test piece 1, and the weight (g) of the test piece 1 was measured. Then, by using the thickness measured in "2. Filter layer (a) thickness of 1" to calculate the volume above the test piece 1 (cm 3), further, the calculated volume (cm 3 ) And the weight (g) of the test piece 1, the density (g / cm 3 ) was calculated. The porosity was calculated based on the following formula (I) using the calculated density (g / cm 3 ).
  • Average flow diameter and average flow diameter pressure Based on ASTM E1294-89 half dry method, average flow diameter and average flow diameter pressure were measured using Galwick (15.9 dyn / cm) as the immersion liquid.
  • PTFE fiber (a) 1 was produced in the same manner as in Example 1, and then PTFE fiber (a) 1 was deposited (superposed) to filter medium layer (a) 2 (length 10 cm, width 10 cm, thickness 20 ⁇ m, A porosity of 0.76) was produced. The thickness and the porosity of the filter medium layer (a) 2 were measured in the same manner as in Example 1. The filter medium layer (a) 2 was cut into a size of 40 mm (A) length and 40 mm (B) width to prepare a sample. The prepared sample was left to stand for 30 minutes in an electric furnace (constant temperature dryer DRA430DA (manufactured by Advantech Toyo Co., Ltd.)) maintained at 260 ° C.
  • an electric furnace constant temperature dryer DRA430DA (manufactured by Advantech Toyo Co., Ltd.)
  • Example 3 The PTFE fiber (a) 1 produced in Example 1 was deposited (superposed) to produce a filter medium layer (a) 3 (length 20 cm, width 20 cm, thickness 59.5 ⁇ m). The thickness of the filter medium layer (a) 3 was measured in the same manner as in Example 1.
  • an air filter (a) is manufactured by sequentially laminating a filter medium layer (a) 3, a stainless steel mesh as the support layer (b), and steel wool as the filter medium layer (c).
  • a filter medium layer (a) 3 a stainless steel mesh as the support layer (b), and steel wool as the filter medium layer (c).
  • the filter medium layer (c) of the air filter (a) was installed inside the CVD apparatus so that the filter medium layer (c) functions as a pre-filter (that is, the filter medium layer (a) 3 is outside the CVD apparatus). Installed).
  • the actual machine operation was performed for 30 days, and the exhaust gas was passed through the air filter (a) when exhaust gas was discharged from the inside of the CVD apparatus to the outside.
  • the air filter (a) was exposed to radical substances such as SiH 3 and SiH 2 contained in the exhaust gas under a high temperature condition of 200 ° C. with the exhaust gas.
  • the filter medium layer (a) 3 is taken out, and the front surface (exhaust gas inlet side (inside the CVD apparatus)) and back surface (exhaust gas outlet surface (outside of the CVD apparatus)) of the filter medium layer (a) 3 are removed. Then, it was subjected to SEM observation (apparatus: S-3400N (manufactured by Hitachi High-Technologies Corporation), magnification: 2000 times) to obtain an electron micrograph.
  • the filter medium layer (a) 3 before being incorporated into the CVD apparatus was subjected to SEM observation under the same conditions to obtain an electron micrograph. The obtained electron micrographs are shown in FIGS.
  • the average flow diameter ( ⁇ m) and the average flow diameter were the same as in Example 1 except that the filter medium layer (a) 3 taken out after the actual machine operation was used instead of the filter medium layer (a) 1. Pressure (psi) was measured. The results are shown in Table 5.
  • FIGS. 1 to 3 SEM photograph before operation of the actual machine (“before use of actual machine”) (FIG. 1), SEM photograph after operation of the actual machine (“after use of actual machine (surface)” (FIG. 2) and “actual machine” Comparing “after use (back surface)” (FIG. 3)), it can be seen that the shape of the PTFE fiber (a) 1 constituting the filter medium layer (a) 3 is not changed at all.
  • the filter medium layer (a) 3 has a function of capturing particles in the exhaust gas discharged from the inside of the CVD apparatus to the outside.
  • the filter medium layer (a) 3 has durability such as radical resistance and heat resistance required for an air filter for a CVD apparatus.

Abstract

[Problem] To provide an air filter for a CVD apparatus achieving filter performance with good balance between low pressure loss and high particle capture rate, and also having the preferred characteristics for use as an air filter for a CVD apparatus, such as excellent heat resistance and plasma resistance. [Solution] The air filter for a CVD apparatus of the present invention is characterized in having a filtering layer (a) including a PTFE fiber (a), the average fiber diameter of the PTFE fiber (a) being 10 nm to 50 µm.

Description

ＣＶＤ装置用エアフィルターおよびそれを有するＣＶＤ装置Air filter for CVD apparatus and CVD apparatus having the same
　本発明は、ＣＶＤ装置に用いられるエアフィルター（ＣＶＤ装置用エアフィルター）およびそれを有するＣＶＤ装置に関する。 The present invention relates to an air filter used in a CVD apparatus (air filter for CVD apparatus) and a CVD apparatus having the same.
　エアフィルターは、空気や原料ガスまたは排気ガスに含まれる微細な粒子を捕集（捕捉）するために用いられ、粒子捕捉率が高いこと（粒子を高い効率で捕集できること）や、圧力損失が低いことが求められる。エアフィルターを構成する材料も、用途に応じて多岐にわたっている。 The air filter is used to collect (capture) fine particles contained in air, source gas or exhaust gas, and has a high particle capture rate (capability of collecting particles with high efficiency) and pressure loss. Low is required. The materials that make up the air filter also vary widely depending on the application.
　エアフィルターを構成する材料として、ポリテトラフルオロエチレン（ＰＴＦＥ）等のフッ素樹脂が知られている。フッ素樹脂は、優れた特性（耐薬品性、耐プラズマ性、耐熱性等）を有するために、フッ素樹脂製エアフィルターは、幅広い用途で使用されている。 Fluorine resin such as polytetrafluoroethylene (PTFE) is known as a material constituting the air filter. Since fluororesins have excellent properties (chemical resistance, plasma resistance, heat resistance, etc.), fluororesin air filters are used in a wide range of applications.
　特許文献１では、複合フィルター媒体とフレームとを含むタービン空気吸入口フィルターが開示され、かかる複合フィルター媒体は、多孔質ポリテトラフルオロエチレン（延伸ＰＴＦＥ）を含む膜フィルター層とデプスフィルター媒体層とを含んでなる。 Patent Document 1 discloses a turbine air inlet filter including a composite filter medium and a frame. The composite filter medium includes a membrane filter layer containing porous polytetrafluoroethylene (expanded PTFE) and a depth filter medium layer. Comprising.
　特許文献２では、特定条件で未焼成のＰＴＦＥを延伸して得られたＰＴＦＥ多孔質膜（延伸ＰＴＦＥ）を備えるフィルター濾材が開示されている。 Patent Document 2 discloses a filter medium including a PTFE porous membrane (stretched PTFE) obtained by stretching unsintered PTFE under specific conditions.
　これらの延伸ＰＴＦＥ製フィルターは、他のポリマー材料で構成されたフィルターに比べて、耐プラズマ性等は優れているものの、依然として、熱収縮などが発生するため、耐熱性等の点で、改善の余地があった。 Although these expanded PTFE filters are superior in plasma resistance and the like compared to filters made of other polymer materials, heat shrinkage and the like still occur. There was room.
　一方で、特許文献３では、ＰＴＦＥ粉末をマトリックス（例：ビスコース）中に分散して水性ディスパージョンを調製し、水性ディスパージョンを凝固浴中に吐出して紡糸して未延伸ＰＴＦＥ系繊維シートを得、未延伸ＰＴＦＥ系繊維シートを加熱焼結し、少なくとも縦方向または横方向に延伸して製造された、フィルター用途に用いられるフッ素繊維薄葉シートが開示されている。 On the other hand, in Patent Document 3, an PTFE powder is dispersed in a matrix (e.g., viscose) to prepare an aqueous dispersion, and the aqueous dispersion is discharged into a coagulation bath and spun to produce an unstretched PTFE fiber sheet. A fluorine fiber thin sheet used for filter applications is disclosed, which is produced by heating and sintering an unstretched PTFE fiber sheet and stretching it at least in the longitudinal direction or the transverse direction.
　また、特許文献４では、フッ素系繊維の抄紙原料を、金網抄き型を用いた湿式抄紙法により脱水、乾燥して成形原体を形成し、成形原体を、加熱処理後の該成形原体の内壁に密着可能な型に載置し、フッ素系繊維の融点以上に加熱して繊維間を融着することにより、予備成形体を作成したのち、さらに予備成形体の形状に対応した雌雄の型に該予備成形体を嵌入し熱圧成形して得られた、フィルター用途に用いられるフッ素繊維成形体が開示されている。 Further, in Patent Document 4, a raw material for paper making of a fluoro fiber is dehydrated and dried by a wet paper making method using a wire netting die to form a forming raw material, and the forming raw material is subjected to the heat treatment after the forming raw material. A male and female corresponding to the shape of the preform after it was placed on a mold that can be in close contact with the inner wall of the body and heated between the melting points of the fluorinated fibers to fuse the fibers together. There is disclosed a fluorine fiber molded article used for a filter, which is obtained by inserting the preform into a mold and hot pressing.
　このようなフッ素繊維からなるフィルターは、圧力損失と粒子捕捉性とをバランスよく両立できず、依然として、フィルター性能について改善の余地があった。 Such a filter made of a fluorine fiber cannot balance pressure loss and particle trapping in a well-balanced manner, and there is still room for improvement in filter performance.
　ところで、化学蒸着（CVD：Chemical Vapor Deposition）法は、基板物質上に、目的とする薄膜の成分を含む原料ガスをＣＶＤ装置内に供給し、基板表面や気相での化学反応により薄膜を堆積する方法である。たとえば、切削工具の表面処理や半導体素子の製造工程において一般的に使用されている。また、ＣＶＤの種類は、薄膜の形成メカニズムに応じて熱ＣＶＤやプラズマＣＶＤ等、多岐にわたっている。 By the way, the chemical vapor deposition (CVD: Chemical Vapor Deposition) method supplies a raw material gas containing the desired thin film components onto the substrate material into the CVD apparatus, and deposits the thin film by chemical reaction on the substrate surface or in the gas phase. It is a method to do. For example, it is generally used in the surface treatment of cutting tools and the manufacturing process of semiconductor elements. Further, the types of CVD are various such as thermal CVD and plasma CVD according to the formation mechanism of the thin film.
　ＣＶＤ装置から排出される排気ガス中には、ＳｉＯ2、ＳｉＨ4、ＳｉＣｌ4を初めとするさまざまな汚染物質が含まれるため、大気中へ放出される前にフィルター等により除去することが求められる。そのためＣＶＤ装置の排気口に設置されるフィルターは、高い粒子捕捉率を有することが求められる。更に、ＣＶＤ装置内部は、高温雰囲気であったり（たとえば、熱ＣＶＤ）、原料ガスがプラズマ状態に励起されていたりする（たとえば、プラズマＣＶＤ）など、過酷な条件になるために、ＣＶＤ装置に用いられるフィルターには、耐熱性や耐プラズマ性（耐ラジカル性）も求められる。 Since the exhaust gas discharged from the CVD apparatus contains various pollutants such as SiO 2 , SiH 4 , and SiCl 4 , it is required to be removed by a filter or the like before being released into the atmosphere. . Therefore, the filter installed at the exhaust port of the CVD apparatus is required to have a high particle capture rate. Furthermore, since the inside of the CVD apparatus is in a high temperature atmosphere (for example, thermal CVD) or the source gas is excited to a plasma state (for example, plasma CVD), it is used in the CVD apparatus. Such a filter is also required to have heat resistance and plasma resistance (radical resistance).
特開２０１１－２０２６６２号公報JP 2011-202662 A 特開２０１１－１０５８９５号公報JP 2011-105895 A 特開平０３－１３０４９６号公報Japanese Patent Laid-Open No. 03-130596 特開平０５－２８７７００号公報JP 05-287700 A
　本発明は、圧力損失が低く、粒子の捕捉率が高いといった、バランスよいフィルター性能を発揮するとともに、耐熱性や耐プラズマ性に優れる等、ＣＶＤ装置用エアフィルターに用いられるのに好適な特性を有するＣＶＤ装置用エアフィルターおよびそれを有するＣＶＤ装置を提供することを目的としている。 The present invention exhibits characteristics suitable for use in an air filter for a CVD apparatus, such as a well-balanced filter performance such as low pressure loss and high particle capture rate, and excellent heat resistance and plasma resistance. An object of the present invention is to provide an air filter for a CVD apparatus and a CVD apparatus having the same.
　本発明者らは鋭意研究した結果、エアフィルターの材料として、特定の平均繊維径を有するＰＴＦＥ繊維を含んでなる濾材層を用いると、圧力損失が低く、粒子の捕捉率が高いといったバランスよいフィルター性能を発揮すること、および、耐熱性や耐プラズマ性に優れることを見出した。そして、本発明者らは、このような、ＣＶＤ装置用エアフィルターとして好適な特性を発揮し得ることに基づいて、本発明を完成させた。 As a result of intensive studies, the present inventors have found that when a filter medium layer containing PTFE fibers having a specific average fiber diameter is used as an air filter material, the pressure loss is low and the particle trapping rate is high. It has been found that it exhibits performance and is excellent in heat resistance and plasma resistance. And the present inventors completed this invention based on being able to exhibit the characteristic suitable as such an air filter for CVD apparatuses.
　すなわち、本発明の要旨は以下の通りである。 That is, the gist of the present invention is as follows.
　［１］　ＰＴＦＥ繊維（ａ）を含んでなる濾材層（ａ）を有するＣＶＤ装置用エアフィルターであって、前記ＰＴＦＥ繊維（ａ）の平均繊維径が、１０ｎｍ～５０μｍであることを特徴とする、ＣＶＤ装置用エアフィルター。 [1] An air filter for a CVD apparatus having a filter medium layer (a) containing PTFE fiber (a), wherein the PTFE fiber (a) has an average fiber diameter of 10 nm to 50 μm. Air filter for CVD equipment.
　［２］　濾材層（ａ）の厚さが、５μｍ～２００μｍであることを特徴とする、［１］に記載のＣＶＤ装置用エアフィルター。 [2] The CVD apparatus air filter according to [1], wherein the thickness of the filter medium layer (a) is 5 μm to 200 μm.
　［３］　濾材層（ａ）の空隙率が、０．６０～０．９５であることを特徴とする、［１］または［２］に記載のＣＶＤ装置用エアフィルター。 [3] The air filter for a CVD apparatus according to [1] or [2], wherein the porosity of the filter medium layer (a) is 0.60 to 0.95.
　［４］　前記ＰＴＦＥ繊維（ａ）が、電界紡糸法により得られたものであることを特徴とする、［１］～［３］の何れか一項に記載のＣＶＤ装置用エアフィルター。 [4] The CVD device air filter according to any one of [1] to [3], wherein the PTFE fiber (a) is obtained by an electrospinning method.
　［５］　濾材層（ａ）の片面または両面に、支持体層（ｂ）が積層されてなることを特徴とする、［１］～［４］の何れか一項に記載のＣＶＤ装置用エアフィルター。 [5] The CVD apparatus air according to any one of [1] to [4], wherein the support layer (b) is laminated on one side or both sides of the filter medium layer (a). filter.
　［６］　［１］～［５］の何れか一項に記載のＣＶＤ装置用エアフィルターが、原料ガス供給口および/またはガス排気口に設置されていることを特徴とする、ＣＶＤ装置。 [6] A CVD apparatus, wherein the air filter for a CVD apparatus according to any one of [1] to [5] is installed at a source gas supply port and / or a gas exhaust port.
　本発明に係るＣＶＤ装置用エアフィルターによれば、高い耐熱性および高い耐ラジカル性（耐プラズマ性）とともに、低い圧力損失および高い粒子捕捉率を有するといったバランスの良い優れたエアフィルター性能が発揮される。 According to the air filter for a CVD apparatus according to the present invention, excellent air filter performance with a good balance such as having a high pressure resistance and a high particle trapping rate as well as high heat resistance and high radical resistance (plasma resistance) is exhibited. The
図１は、実施例３で得られた実機使用前の電子顕微鏡写真を示す図である。FIG. 1 is a view showing an electron micrograph obtained in Example 3 before using the actual machine. 図２は、実施例３で得られた実機使用後（表面）の電子顕微鏡写真を示す図である。FIG. 2 is an electron micrograph obtained after using the actual machine (surface) obtained in Example 3. 図３は、実施例３で得られた実機使用後（裏面）の電子顕微鏡写真を示す図である。FIG. 3 is a view showing an electron micrograph of the actual machine obtained in Example 3 after use (back side).
　以下、本発明をより詳細に説明する。 Hereinafter, the present invention will be described in more detail.
　本発明に係るＣＶＤ装置用エアフィルター（以後、単に「エアフィルター」と称する場合もある。）は、必須構成要件として、１０ｎｍ～５０μｍの平均繊維径を有するポリテトラフルオロエチレン繊維（ａ）(ＰＴＦＥ繊維（ａ）)を含んでなる濾材層（ａ）を有し、必要に応じて、後述するように、濾材層（ａ）の片面または両面に、支持体層（ｂ）が積層されていてもよい。 The air filter for a CVD apparatus according to the present invention (hereinafter sometimes simply referred to as “air filter”) has, as an essential component, a polytetrafluoroethylene fiber (a) (PTFE) having an average fiber diameter of 10 nm to 50 μm. A filter medium layer (a) comprising fibers (a)), and a support layer (b) is laminated on one side or both sides of the filter medium layer (a) as necessary, as will be described later. Also good.
　本発明のエアフィルターは、ＣＶＤ（化学蒸着）装置に、（具体的には、該装置の原料ガス供給口および／または排気ガス排出口に、原料ガスおよび／または排気ガスを濾過できるような状態で）設置して、装置内に供給される原料ガスおよび／または装置内から排出される排気ガスを濾過して、原料ガスおよび/または排気ガスに含まれる粒子（塵、ダスト）を捕集（捕捉）するために用いられる。そして、本発明のエアフィルターは、高い耐熱性および高い耐ラジカル性（耐プラズマ性）とともに、低い圧力損失および高い粒子捕捉率といったバランスの良い優れたエアフィルター性能が発揮されるために、原料ガスの種類、基板への蒸着メカニズムを問わず、様々なタイプのＣＶＤ装置に使用することができる。なお、ＣＶＤ装置としては、熱ＣＶＤ装置、プラズマＣＶＤ装置、光ＣＶＤ装置、ＭＯＣＶＤ（metalorganoic CVD）装置が挙げられる。 The air filter of the present invention is in a state where the source gas and / or the exhaust gas can be filtered into a CVD (chemical vapor deposition) apparatus (specifically, the source gas supply port and / or the exhaust gas discharge port of the apparatus). And collect the particles (dust, dust) contained in the raw material gas and / or exhaust gas by filtering the raw material gas supplied into the device and / or the exhaust gas exhausted from inside the device ( Used to capture). The air filter of the present invention exhibits excellent air filter performance such as high heat resistance and high radical resistance (plasma resistance) as well as well-balanced air filter performance such as low pressure loss and high particle capture rate. It can be used for various types of CVD apparatuses regardless of the type of deposition and the mechanism of vapor deposition on the substrate. Examples of the CVD apparatus include a thermal CVD apparatus, a plasma CVD apparatus, a photo CVD apparatus, and a MOCVD (metalorgano-CVD) apparatus.
　本発明のエアフィルターにおいて、ＰＴＦＥ繊維（ａ）の平均繊維径は、１０ｎｍ～５０μｍであり、好ましくは、１００ｎｍ～５０００ｎｍである。ＰＴＦＥ繊維（ａ）の平均繊維径がこのような範囲にあることで、圧力損失が低減されるとともに、粒子捕捉率が向上するなど、エアフィルター性能を向上させることができる。 In the air filter of the present invention, the average fiber diameter of the PTFE fiber (a) is 10 nm to 50 μm, preferably 100 nm to 5000 nm. When the average fiber diameter of the PTFE fiber (a) is in such a range, the pressure loss can be reduced and the air trapping performance can be improved, for example, the particle capture rate can be improved.
　ここで、ＰＴＦＥ繊維（ａ）の平均繊維径とは、測定対象となるＰＴＦＥ繊維（ａ）について、無作為に走査型電子顕微鏡（ＳＥＭ）観察される領域を選び、次いで、この領域をＳＥＭ観察（倍率：１００００倍）して無作為に１０本のＰＴＦＥ繊維（ａ）を選び、選ばれた１０本のＰＴＦＥ繊維（ａ）の繊維径を測定し、得られた１０本の繊維径の値に基づいて算出される算術平均値である。 Here, the average fiber diameter of the PTFE fiber (a) is a region that is randomly observed by a scanning electron microscope (SEM) for the PTFE fiber (a) to be measured, and this region is then observed by SEM. (Magnification: 10,000 times) 10 PTFE fibers (a) were selected at random, the fiber diameters of the 10 selected PTFE fibers (a) were measured, and the obtained 10 fiber diameter values. Is an arithmetic average value calculated based on
　後述するように、ＰＴＦＥ繊維（ａ）が電界紡糸法によって得られるものである場合、紡糸液中のＰＴＦＥ濃度、製造時の雰囲気湿度、紡糸ノズルの先端径、印加電圧、電圧密度などを適宜調整することで、所望の平均繊維径を有するＰＴＦＥ繊維（ａ）を得ることができる。なお、電界紡糸法において、ＰＴＦＥ濃度が低い紡糸液を用いる、雰囲気湿度を下げる、紡糸ノズルの先端径を小さくする、印加電圧を大きくする、あるいは電圧密度を大きくするなどにより、ＰＴＦＥ繊維（ａ）の平均繊維径は小さくなる傾向にある。 As will be described later, when the PTFE fiber (a) is obtained by an electrospinning method, the PTFE concentration in the spinning solution, the atmospheric humidity during production, the tip diameter of the spinning nozzle, the applied voltage, the voltage density, etc. are appropriately adjusted. By doing so, PTFE fiber (a) having a desired average fiber diameter can be obtained. In the electrospinning method, the PTFE fiber (a) is obtained by using a spinning solution having a low PTFE concentration, lowering the atmospheric humidity, reducing the tip diameter of the spinning nozzle, increasing the applied voltage, or increasing the voltage density. The average fiber diameter tends to be small.
　「ＰＴＦＥ繊維（ａ）」とは、ＰＴＦＥを、通常９５～１００重量％、好ましくは９９～１００重量％、より好ましくは１００重量％の含有量で含む繊維である。本発明に係るＣＶＤ装置用エアフィルターは、ＰＴＦＥ繊維（ａ）の特性に起因して、耐プラズマ性（耐ラジカル性）や耐熱性（特に、低い熱収縮性）などを発揮することができる。 “PTFE fiber (a)” is a fiber containing PTFE in a content of usually 95 to 100% by weight, preferably 99 to 100% by weight, more preferably 100% by weight. The air filter for a CVD apparatus according to the present invention can exhibit plasma resistance (radical resistance), heat resistance (particularly low heat shrinkage), and the like due to the characteristics of the PTFE fiber (a).
　ＰＴＦＥ繊維（ａ）の製造方法は、上記範囲の平均繊維径を有するＰＴＦＥ繊維を製造する方法である限り、特に限定されるものではないが、電界紡糸（静電紡糸）法により得られたものが好ましい。電界紡糸法は、上記範囲の平均繊維径を有するＰＴＦＥ繊維（ａ）を容易に得ることができ、本発明におけるエアフィルターに、このような方法で得られたＰＴＦＥ繊維（ａ）を用いると、高い粒子捕捉率、低い圧力損失、熱やラジカルや有害物質への高い耐久性を有するエアフィルターを実現できるようになる。 The method for producing PTFE fiber (a) is not particularly limited as long as it is a method for producing PTFE fiber having an average fiber diameter in the above range, but is obtained by electrospinning (electrostatic spinning) method. Is preferred. The electrospinning method can easily obtain the PTFE fiber (a) having an average fiber diameter in the above range, and when the PTFE fiber (a) obtained by such a method is used for the air filter in the present invention, An air filter having a high particle trapping rate, low pressure loss, and high durability against heat, radicals and harmful substances can be realized.
　上記電界紡糸法として、上述したＰＴＦＥおよび溶媒、さらには必要に応じて添加剤（繊維形成剤、イオン性界面活性剤、粘度調整剤等）を含む紡糸液から、例えば米国特開２０１０／０１９３９９９　Ａ１号公報に記載の方法など公知の電界紡糸法を用いることができる。 As the electrospinning method, for example, from the spinning solution containing the above-mentioned PTFE and a solvent, and optionally additives (fiber forming agent, ionic surfactant, viscosity modifier, etc.), for example, US 2010/0193999 A1. A known electrospinning method such as the method described in Japanese Patent Publication No. 1993-2011 can be used.
　濾材層（ａ）の空隙率（多孔度）は、圧力損失の増加を防ぐための流体流路の確保、ろ材強度の確保という観点からは、好ましくは、０．６０～０．９５であり、より好ましくは０．７０～０．９０である。 The porosity (porosity) of the filter medium layer (a) is preferably 0.60 to 0.95 from the viewpoint of securing a fluid flow path for preventing an increase in pressure loss and securing the filter medium strength. More preferably, it is 0.70 to 0.90.
　濾材層（ａ）の目付は、ＰＴＦＥ繊維の繊維径にもよるが、高粒子捕捉性能と低圧力損失との両立、濾材強度の確保という観点からは、好ましくは１～２００ｇ／ｍ2であり、より好ましくは１０～１００ｇ／ｍ2である。 Although the basis weight of the filter medium layer (a) depends on the fiber diameter of the PTFE fiber, it is preferably 1 to 200 g / m 2 from the viewpoint of achieving both high particle capturing performance and low pressure loss and ensuring the filter medium strength. More preferably, it is 10 to 100 g / m 2 .
　濾材層（ａ）の厚さは、ＰＴＦＥ繊維の繊維径にもよるが、高粒子捕捉性能と低圧力損失との両立という観点からは、好ましくは５μｍ～２００μｍである。 Although the thickness of the filter medium layer (a) depends on the fiber diameter of the PTFE fiber, it is preferably 5 μm to 200 μm from the viewpoint of achieving both high particle capturing performance and low pressure loss.
　なお、濾材層（ａ）における、空隙率、目付および厚さは、電界紡糸法を用いてＰＴＦＥ繊維（ａ）を調製する際に、紡糸時間を長くする、紡糸ノズル数を増やすなどにより、増大する傾向にある。 The porosity, basis weight, and thickness in the filter medium layer (a) are increased by increasing the spinning time or increasing the number of spinning nozzles when preparing the PTFE fiber (a) using the electrospinning method. Tend to.
　本発明に係るＣＶＤ装置用エアフィルターの製造方法は、特に限定されないが、たとえば、上述したような電界紡糸法によりＰＴＦＥ繊維（ａ）を製造する工程、および前記ＰＴＦＥ繊維（ａ）をシート状に集積してエアフィルターを形成する工程を含むものである。 Although the manufacturing method of the air filter for CVD apparatus which concerns on this invention is not specifically limited, For example, the process of manufacturing PTFE fiber (a) by the above-mentioned electrospinning method, and said PTFE fiber (a) in a sheet form It includes a step of accumulating to form an air filter.
　なお、これら２つの工程は、別途独立に行ってもよく、同時に行ってもよい（すなわち、ＰＴＦＥ繊維（ａ）を製造しつつシート状に集積して、濾材層（ａ）を形成してもよい）。 Note that these two steps may be performed separately or simultaneously (that is, the filter medium layer (a) may be formed by collecting the PTFE fibers (a) in a sheet shape and forming them). Good).
　また、本発明に係るエアフィルターは、支持体層（ｂ）などが積層されていない、濾材層（ａ）のみからなるもの（単層型エアフィルター）であってもよいし、さらに、濾材層（ａ）の片面または両面に支持体層（ｂ）等が積層されてなるもの（積層型エアフィルター）であってもよい。 In addition, the air filter according to the present invention may be a filter medium layer (a) that is not laminated with a support layer (b) or the like (single-layer air filter), and may further include a filter medium layer. The support layer (b) or the like (laminated air filter) may be laminated on one or both sides of (a).
　なお、上記積層エアフィルターは、たとえば、上記のように特定の平均繊維径を有するＰＴＦＥ繊維（ａ）を作製する工程と、支持体層（ｂ）の少なくとも一方の表面にＰＴＦＥ繊維（ａ）をシート状に集積して濾材層（ａ）を形成する工程とを実施することで作製できる。これら２つの工程は、別途独立に行ってもよく、同時に行ってもよい（すなわち、ＰＴＦＥ繊維（ａ）を、製造しつつ支持体層（ｂ）の少なくとも一方の表面にシート状に集積して、濾材層（ａ）を形成してもよい）。 The laminated air filter includes, for example, a step of producing PTFE fibers (a) having a specific average fiber diameter as described above, and PTFE fibers (a) on at least one surface of the support layer (b). It can produce by implementing the process of accumulating in a sheet form and forming a filter medium layer (a). These two steps may be performed separately or simultaneously (that is, PTFE fibers (a) are accumulated in a sheet form on at least one surface of the support layer (b) while being produced). The filter medium layer (a) may be formed).
　また、支持体層（ｂ）としては、エアフィルターにおける従来公知の支持体層を用いることができ、たとえば鉄、銅、ステンレス等から構成されるメッシュ、たとえばガラス繊維、セルロース繊維、ポリオレフィン繊維、ナイロン繊維、ポリエステル繊維などから構成される不織布などが挙げられる。中でも、耐久性の観点からは、支持体層（ｂ）は鉄、銅、ステンレス等から構成されるメッシュまたはガラス繊維から構成される不織布からなることが好ましい。 Moreover, as a support body layer (b), the conventionally well-known support body layer in an air filter can be used, for example, the mesh comprised from iron, copper, stainless steel etc., for example, glass fiber, a cellulose fiber, polyolefin fiber, nylon Nonwoven fabrics composed of fibers, polyester fibers and the like can be mentioned. Especially, from a viewpoint of durability, it is preferable that a support body layer (b) consists of a nonwoven fabric comprised from the mesh or glass fiber comprised from iron, copper, stainless steel, etc.
　また、本発明のエアフィルターは、ＰＴＦＥ繊維（ａ）を含んでなる濾材層（ａ）の他に、前記濾材層（ａ）とは材質の異なる１つ以上の濾材層（ｃ）を有していてもよい。この場合、本発明のエアフィルターは濾材層（ａ）と１つ以上の濾材層（ｃ）からなるものであってもよいし、さらに1つ以上の支持体層（ｂ）を積層してなるものであってもよい。濾材層の目詰まりの防止につながるため、エアフィルターの長期性能保持の観点から、複数の濾材層により塵（ダスト）を粒径毎に捕集していくことが好ましい。 In addition, the air filter of the present invention has at least one filter medium layer (c) made of a material different from the filter medium layer (a) in addition to the filter medium layer (a) comprising PTFE fibers (a). It may be. In this case, the air filter of the present invention may be composed of a filter medium layer (a) and one or more filter medium layers (c), and further laminated with one or more support layers (b). It may be a thing. In order to prevent clogging of the filter medium layer, it is preferable to collect dust for each particle diameter by a plurality of filter medium layers from the viewpoint of maintaining long-term performance of the air filter.
　濾材層（ｃ）としては、耐久性の観点から金属性であることが好ましく、金属焼結粉末からなるパウダー状濾材、焼結金属金網からなるメッシュ状濾材、金属繊維からなるウール状及び不織布状濾材など従来公知のものを用いることができる。 The filter medium layer (c) is preferably metallic from the viewpoint of durability, and is a powder filter medium made of a sintered metal powder, a mesh filter medium made of a sintered metal wire mesh, a wool and a nonwoven cloth made of metal fibers. Conventionally known materials such as filter media can be used.
　また、本発明のエアフィルターには、その性能を損なわない範囲で従来公知の加工が施されていてもよく、たとえばプリーツ加工が施されていてもよい。 In addition, the air filter of the present invention may be subjected to conventionally known processing within a range not impairing its performance, for example, may be subjected to pleating.
　以下、本発明を実施例によりさらに詳細に説明するが、本発明はこれらの実施例により何ら限定されるものではない。 Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
　［実施例１］
　既存の電界紡糸法によりＰＴＦＥのみからなるＰＴＦＥ繊維（ａ）１を製造した。製造されたＰＴＦＥ繊維（ａ）１の特性を、下記「測定方法・評価基準」に基づいて、測定または評価した。得られた結果を表１に示す。 [Example 1]
PTFE fiber (a) 1 consisting only of PTFE was produced by an existing electrospinning method. The properties of the produced PTFE fiber (a) 1 were measured or evaluated based on the following “measurement method / evaluation criteria”. The obtained results are shown in Table 1.
　次いで、ＰＴＦＥ繊維（ａ）１を堆積して（重ね合わせて）濾材層（ａ）１（縦１０ｃｍ、横１０ｃｍ）を製造した。製造された濾材層（ａ）１の特性を、下記「測定方法・評価基準」に基づいて、測定または評価した。得られた結果を表１に示す。 Next, PTFE fiber (a) 1 was deposited (superposed) to produce a filter medium layer (a) 1 (length 10 cm, width 10 cm). The characteristics of the produced filter medium layer (a) 1 were measured or evaluated based on the following “measurement method / evaluation criteria”. The obtained results are shown in Table 1.
　［測定方法・評価基準］
　１．ＰＴＦＥ繊維（ａ）１の平均繊維径
　ＰＴＦＥ繊維（ａ）１について、無作為にＳＥＭ観察の領域を選び、この領域をＳＥＭ観察（装置：Ｓ－３４００Ｎ（（株）日立ハイテクノロジーズ製）、倍率：１００００倍）して無作為に１０本のＰＴＦＥ繊維（ａ）１を選び、これらのＰＴＦＥ繊維（ａ）１の測定結果に基づいて、平均（算術平均）繊維径を算出した。 [Measurement method and evaluation criteria]
1. PTFE fiber (a) 1 average fiber diameter For PTFE fiber (a) 1, a region for SEM observation was randomly selected, and this region was subjected to SEM observation (device: S-3400N (manufactured by Hitachi High-Technologies Corporation)), magnification 10 times), 10 PTFE fibers (a) 1 were selected at random, and the average (arithmetic average) fiber diameter was calculated based on the measurement results of these PTFE fibers (a) 1.
　２．濾材層（ａ）１の厚さ
　濾材層（ａ）１の厚さを、ＬＩＴＥＭＡＴＩＣ　ＶＬ－５０（（株）ミツトヨ製）により測定した。 2. Thickness of the filter medium layer (a) 1 The thickness of the filter medium layer (a) 1 was measured by LITEMATAC VL-50 (manufactured by Mitutoyo Corporation).
　３．濾材層（ａ）１の目付
　濾材層（ａ）１の目付（ｇ/ｍ2）を、ＪＩＳ　Ｌ　１９０６（２０００）に準じて測定した。 3. The basis weight (g / m 2 ) of the filter medium layer (a) 1 of the filter medium layer (a) 1 was measured according to JIS L 1906 (2000).
　４．空隙率
　濾材層（ａ）１を４ｃｍ角（縦４ｃｍ×横４ｃｍ）に切り出して、試験片１を作成し、かかる試験片１の重量（ｇ）を測定した。次いで、「２．濾材層（ａ）１の厚さ」の項で測定された厚さを用いて、上記試験片１の体積（ｃｍ3）を算出し、さらに、算出された体積（ｃｍ3）と試験片１の重量（ｇ）とから密度（ｇ/ｃｍ3）を算出した。算出された密度（ｇ/ｃｍ3）を用いて、下記式（Ｉ）に基づいて空隙率を算出した。 4). The porosity filter medium layer (a) 1 was cut into a 4 cm square (4 cm long × 4 cm wide) to prepare a test piece 1, and the weight (g) of the test piece 1 was measured. Then, by using the thickness measured in "2. Filter layer (a) thickness of 1" to calculate the volume above the test piece 1 (cm 3), further, the calculated volume (cm 3 ) And the weight (g) of the test piece 1, the density (g / cm 3 ) was calculated. The porosity was calculated based on the following formula (I) using the calculated density (g / cm 3 ).
Figure JPOXMLDOC01-appb-M000001
 　５．平均流量径および平均流量径圧力
　ＡＳＴＭ　Ｅ１２９４－８９のハーフドライ法に基づき、Ｇａｌｗｉｃｋ（15.9ｄｙｎ/ｃｍ）を浸漬液として用いて平均流量径および平均流量径圧力を測定した。
Figure JPOXMLDOC01-appb-M000001
 5). Average flow diameter and average flow diameter pressure Based on ASTM E1294-89 half dry method, average flow diameter and average flow diameter pressure were measured using Galwick (15.9 dyn / cm) as the immersion liquid.
　縦軸が流量を、横軸が濾材層（ａ）１に供される圧力を示す、Ｇａｌｗｉｃｋ（浸漬液）に浸漬されていない濾材層（ａ）１の通気曲線（ドライカーブ）と、Ｇａｌｗｉｃｋ（浸漬液）に浸漬された濾材層（ａ）１の通気曲線（ウェットカーブ）とを作成した。さらに、ドライカーブの傾きを算出し、ドライカーブの１/２の値の傾きを有する曲線（ハーフドライカーブ）を作成した。 The aeration curve (dry curve) of the filter medium layer (a) 1 not immersed in Galwick (immersion liquid), the vertical axis indicates the flow rate, and the horizontal axis indicates the pressure applied to the filter medium layer (a) 1, and Galwick ( A ventilation curve (wet curve) of the filter medium layer (a) 1 immersed in the immersion liquid) was prepared. Further, the slope of the dry curve was calculated, and a curve (half dry curve) having a half of the value of the dry curve was created.
　次いで、ウェットカーブとハーフドライカーブとの交点における圧力（平均流量径圧力）を求め、これを下記のWashburnの式に代入し、平均流量径ｄを算出した。 Next, the pressure at the intersection of the wet curve and the half dry curve (average flow diameter pressure) was determined, and this was substituted into the following Washburn equation to calculate the average flow diameter d.
　　ｄ＝４γｃｏｓθ／Ｐ
　　（式中、θは濾材層と浸漬液との接触角を、γ[Ｎ／ｍ]は浸漬液の表面張力を、Ｐは平均流量径圧力を表す。）
　６．粒子捕捉率および圧力損失
　濾材層（ａ）１について、ＪＩＳ　Ｂ　９９０８に準じて、粒子捕捉率を測定した。この際、エアフィルターユニットの替わりに２００ｍｍ×２００ｍｍの大きさに切り出された濾材層（ａ）１を用い、測定用粉塵として、表２に示されるような特定粒子径範囲を有する大気塵を用いた。粒子捕捉率の測定の際には、空気の流量を面速度５．３ｃｍ／ｓとした。また、この測定と共に、濾材層（ａ）１の上流側および下流側での圧力の差（すなわち、圧力損失）を微差圧計により測定した。この測定は、表３に示されるように空気の流量を変えて行った。 d = 4γ cos θ / P
(In the formula, θ represents the contact angle between the filter medium layer and the immersion liquid, γ [N / m] represents the surface tension of the immersion liquid, and P represents the average flow diameter pressure.)
6). For the particle trapping rate and the pressure loss filter medium layer (a) 1, the particle trapping rate was measured according to JIS B 9908. At this time, instead of the air filter unit, the filter medium layer (a) 1 cut into a size of 200 mm × 200 mm was used, and atmospheric dust having a specific particle diameter range as shown in Table 2 was used as measurement dust. It was. When measuring the particle capture rate, the air flow rate was set to a surface velocity of 5.3 cm / s. Further, along with this measurement, the pressure difference (that is, pressure loss) between the upstream side and the downstream side of the filter medium layer (a) 1 was measured with a fine differential pressure gauge. This measurement was performed by changing the air flow rate as shown in Table 3.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000004
 　［実施例２］
　実施例１と同様にＰＴＦＥ繊維（ａ）１を製造し、次いで、ＰＴＦＥ繊維（ａ）１を堆積して（重ね合わせて）濾材層（ａ）２（縦１０ｃｍ、横１０ｃｍ、厚さ２０μｍ、空隙率０．７６）を製造した。なお、濾材層（ａ）２の厚さおよび空隙率は、実施例１と同様に測定されたものである。この濾材層（ａ）２を縦４０ｍｍ（Ａ）、横４０ｍｍ（Ｂ）の寸法に切り出してサンプルを作製した。作製されたサンプルを、枠など固定器具による固定をせずに２６０℃に保持された電気炉（定温乾燥器ＤＲＡ４３０ＤＡ（アドバンテック東洋株式会社製））内に３０分間静置した。その後電気炉より取り出し、室温まで空冷後、熱処理後の寸法として縦の長さ（ａ）および横の長さ（ｂ）を測定した。熱処理前の縦の長さ（Ａ）および横の長さ（Ｂ）と、熱処理後の縦の長さ（ａ）および横の長さ（ｂ）の長さと下記式に基づいて、縦および横における収縮率（％）を算出した。結果を表４に示す
Figure JPOXMLDOC01-appb-T000004
 [Example 2]
PTFE fiber (a) 1 was produced in the same manner as in Example 1, and then PTFE fiber (a) 1 was deposited (superposed) to filter medium layer (a) 2 (length 10 cm, width 10 cm, thickness 20 μm, A porosity of 0.76) was produced. The thickness and the porosity of the filter medium layer (a) 2 were measured in the same manner as in Example 1. The filter medium layer (a) 2 was cut into a size of 40 mm (A) length and 40 mm (B) width to prepare a sample. The prepared sample was left to stand for 30 minutes in an electric furnace (constant temperature dryer DRA430DA (manufactured by Advantech Toyo Co., Ltd.)) maintained at 260 ° C. without being fixed by a fixing device such as a frame. Then, it was taken out from the electric furnace, air-cooled to room temperature, and the vertical length (a) and the horizontal length (b) were measured as dimensions after the heat treatment. Based on the vertical length (A) and the horizontal length (B) before the heat treatment, the vertical length (a) and the horizontal length (b) after the heat treatment, and the following formula, The shrinkage percentage (%) was calculated. The results are shown in Table 4.
Figure JPOXMLDOC01-appb-M000005
 　［比較例１］
　実施例２において濾材層（ａ）２の代わりに延伸ＰＴＦＥ（縦４０ｍｍ、横４０ｍｍ、厚さ１０８μｍ、空隙率０．８６：住友電気工業株式会社製ポアフロン（登録商標）メンブレン）を用いた以外は同様に、２６０℃での熱処理後の収縮率の評価を行なった。結果を表４に示す。
Figure JPOXMLDOC01-appb-M000005
 [Comparative Example 1]
Except for using expanded PTFE (length 40 mm, width 40 mm, thickness 108 μm, porosity 0.86: Poaflon (registered trademark) membrane manufactured by Sumitomo Electric Industries, Ltd.) instead of the filter medium layer (a) 2 in Example 2. Similarly, the shrinkage rate after heat treatment at 260 ° C. was evaluated. The results are shown in Table 4.
Figure JPOXMLDOC01-appb-T000006
 　表４に示されるように、比較例における延伸ＰＴＦＥにおいては、２６０℃の熱処理前後で収縮が生じており、高温雰囲気下における形状安定性、すなわち耐熱性に課題があることが分かる。一方、本発明の濾材層（ａ）２においては、２６０℃の熱処理環境下においてもほとんど収縮せず、熱に対する形状安定性が高いことが分かる。すなわち、濾材層（ａ）２は高温環境下でも使用しうる耐熱性を有していることが理解される。
Figure JPOXMLDOC01-appb-T000006
 As shown in Table 4, in the expanded PTFE in the comparative example, shrinkage occurs before and after the heat treatment at 260 ° C., and it can be seen that there is a problem in shape stability under high temperature atmosphere, that is, heat resistance. On the other hand, it can be seen that the filter medium layer (a) 2 of the present invention hardly shrinks even in a heat treatment environment at 260 ° C. and has high shape stability against heat. That is, it is understood that the filter medium layer (a) 2 has heat resistance that can be used even in a high temperature environment.
　［実施例３］
　実施例１で製造されたＰＴＦＥ繊維（ａ）１を堆積して（重ね合わせて）、濾材層（ａ）３（縦２０ｃｍ、横２０ｃｍ、厚さ５９．５μｍ）を製造した。なお、濾材層（ａ）３の厚さは、実施例１と同様にして測定されたものである。 [Example 3]
The PTFE fiber (a) 1 produced in Example 1 was deposited (superposed) to produce a filter medium layer (a) 3 (length 20 cm, width 20 cm, thickness 59.5 μm). The thickness of the filter medium layer (a) 3 was measured in the same manner as in Example 1.
　次に、濾材層（ａ）３、支持体層（ｂ）としてステンレス製メッシュ、濾材層（ｃ）としてスチールウールを順次積層することによりエアフィルター（ａ）を製造し、エアフィルター（ａ）を、シリコン膜形成用プラズマＣＶＤ装置のガス排気口に、従来のエアフィルターの代わりに組み込んだ。ここで、濾材層（ｃ）がプレフィルターとして機能するように、エアフィルター（ａ）の濾材層（ｃ）をＣＶＤ装置内部側に設置した（すなわち、濾材層（ａ）３はＣＶＤ装置外部側に設置されている）。 Next, an air filter (a) is manufactured by sequentially laminating a filter medium layer (a) 3, a stainless steel mesh as the support layer (b), and steel wool as the filter medium layer (c). Instead of the conventional air filter, it was incorporated in the gas exhaust port of the plasma CVD apparatus for forming a silicon film. Here, the filter medium layer (c) of the air filter (a) was installed inside the CVD apparatus so that the filter medium layer (c) functions as a pre-filter (that is, the filter medium layer (a) 3 is outside the CVD apparatus). Installed).
　次いで、３０日間の実機運転を行ない、排気ガスを、ＣＶＤ装置内部から外部へ排出する際に、エアフィルター（ａ）を通過させた。ここで、エアフィルター（ａ）は、排気ガスによって２００℃の高温条件下で、排気ガスに含まれるＳｉＨ3、ＳｉＨ2等のラジカル物質に曝された。 Next, the actual machine operation was performed for 30 days, and the exhaust gas was passed through the air filter (a) when exhaust gas was discharged from the inside of the CVD apparatus to the outside. Here, the air filter (a) was exposed to radical substances such as SiH 3 and SiH 2 contained in the exhaust gas under a high temperature condition of 200 ° C. with the exhaust gas.
　実機運転終了後、濾材層（ａ）３を取り出して、濾材層（ａ）３の表面（排気ガス入り口側（ＣＶＤ装置内部側））及び裏面（排気ガス出口面（ＣＶＤ装置外部側））を、ＳＥＭ観察（装置：Ｓ－３４００Ｎ（（株）日立ハイテクノロジーズ製）、倍率：２０００倍）に供して、電子顕微鏡写真を得た。なお、ＣＶＤ装置に組み込む前の濾材層（ａ）３を、同様の条件でＳＥＭ観察に供して電子顕微鏡写真を得た。得られた各電子顕微鏡写真を図１～３に示す。 After the operation of the actual machine is completed, the filter medium layer (a) 3 is taken out, and the front surface (exhaust gas inlet side (inside the CVD apparatus)) and back surface (exhaust gas outlet surface (outside of the CVD apparatus)) of the filter medium layer (a) 3 are removed. Then, it was subjected to SEM observation (apparatus: S-3400N (manufactured by Hitachi High-Technologies Corporation), magnification: 2000 times) to obtain an electron micrograph. The filter medium layer (a) 3 before being incorporated into the CVD apparatus was subjected to SEM observation under the same conditions to obtain an electron micrograph. The obtained electron micrographs are shown in FIGS.
　また、濾材層（ａ）１ではなく、実機運転終了後に取り出された濾材層（ａ）３を用いたことを除いては、実施例１と同様にして平均流量径（μｍ）および平均流量径圧力（ｐｓｉ）を測定した。結果を表５に示す。 Further, the average flow diameter (μm) and the average flow diameter were the same as in Example 1 except that the filter medium layer (a) 3 taken out after the actual machine operation was used instead of the filter medium layer (a) 1. Pressure (psi) was measured. The results are shown in Table 5.
Figure JPOXMLDOC01-appb-T000007
 　図１～３に示されるように、実機運転前のＳＥＭ写真（「実機使用前」）（図１）と実機運転後のＳＥＭ写真（「実機使用後（表面）」（図２）および「実機使用後（裏面）」（図３））とを対比すると、濾材層（ａ）３を構成しているＰＴＦＥ繊維（ａ）１の形状は、何ら変化していないことが分かる。
Figure JPOXMLDOC01-appb-T000007
 As shown in FIGS. 1 to 3, SEM photograph before operation of the actual machine (“before use of actual machine”) (FIG. 1), SEM photograph after operation of the actual machine (“after use of actual machine (surface)” (FIG. 2) and “actual machine” Comparing “after use (back surface)” (FIG. 3)), it can be seen that the shape of the PTFE fiber (a) 1 constituting the filter medium layer (a) 3 is not changed at all.
　また、図２の「実機使用後（表面）」に示されるように、濾材層（ａ）３の表面に粒子状の物質が捕捉されていることが分かる。すなわち、濾材層（ａ）３が、ＣＶＤ装置内から外部へ排出される排気ガス中の粒子を捕捉する機能を有することが理解される。 Further, as shown in “after use of actual machine (surface)” in FIG. 2, it can be seen that particulate matter is trapped on the surface of the filter medium layer (a) 3. That is, it is understood that the filter medium layer (a) 3 has a function of capturing particles in the exhaust gas discharged from the inside of the CVD apparatus to the outside.
　さらに、表５に示されるように、実機使用前後において、捕捉粒子によるわずかな平均流量径の減少及び平均流量径圧力の増加が見られたが、フィルターの損傷と想定されるような大きな変化は見られなかった。すなわち、濾材層（ａ）３はＣＶＤ装置用エアフィルターに必要とされる耐ラジカル性および耐熱性等の耐久性を有していることが理解される。 Furthermore, as shown in Table 5, there was a slight decrease in the average flow diameter due to trapped particles and an increase in the average flow diameter pressure before and after using the actual machine. I couldn't see it. That is, it is understood that the filter medium layer (a) 3 has durability such as radical resistance and heat resistance required for an air filter for a CVD apparatus.

Claims (6)

  1. 　ＰＴＦＥ繊維（ａ）を含んでなる濾材層（ａ）を有するＣＶＤ装置用エアフィルターであって、前記ＰＴＦＥ繊維（ａ）の平均繊維径が、１０ｎｍ～５０μｍであることを特徴とする、ＣＶＤ装置用エアフィルター。 A CVD apparatus air filter having a filter medium layer (a) comprising PTFE fibers (a), wherein the PTFE fibers (a) have an average fiber diameter of 10 nm to 50 μm Air filter.
  2. 　濾材層（ａ）の厚さが、５μｍ～２００μｍであることを特徴とする、請求項１に記載のＣＶＤ装置用エアフィルター。 2. The air filter for a CVD apparatus according to claim 1, wherein the thickness of the filter medium layer (a) is 5 μm to 200 μm.
  3. 　濾材層（ａ）の空隙率が、０．６０～０．９５であることを特徴とする、請求項１または２に記載のＣＶＤ装置用エアフィルター。 3. The air filter for a CVD apparatus according to claim 1, wherein the porosity of the filter medium layer (a) is 0.60 to 0.95.
  4. 　前記ＰＴＦＥ繊維（ａ）が、電界紡糸法により得られたものであることを特徴とする、請求項１～３の何れか一項に記載のＣＶＤ装置用エアフィルター。 The air filter for a CVD apparatus according to any one of claims 1 to 3, wherein the PTFE fiber (a) is obtained by an electrospinning method.
  5. 　濾材層（ａ）の片面または両面に、支持体層（ｂ）が積層されてなることを特徴とする、請求項１～４の何れか一項に記載のＣＶＤ装置用エアフィルター。 The CVD apparatus air filter according to any one of claims 1 to 4, wherein the support layer (b) is laminated on one side or both sides of the filter medium layer (a).
  6. 　請求項１～５の何れか一項に記載のＣＶＤ装置用エアフィルターが、原料ガス供給口および/またはガス排気口に設置されていることを特徴とする、ＣＶＤ装置。 A CVD apparatus, wherein the CVD apparatus air filter according to any one of claims 1 to 5 is installed at a source gas supply port and / or a gas exhaust port.
PCT/JP2013/056731 2012-03-19 2013-03-12 Air filter for cvd apparatus, and cvd apparatus having same WO2013141070A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012-062364 2012-03-19
JP2012062364A JP2013193025A (en) 2012-03-19 2012-03-19 Air filter for cvd device and cvd device with the same

Publications (1)

Publication Number Publication Date
WO2013141070A1 true WO2013141070A1 (en) 2013-09-26

Family

ID=49222530

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/056731 WO2013141070A1 (en) 2012-03-19 2013-03-12 Air filter for cvd apparatus, and cvd apparatus having same

Country Status (3)

Country Link
JP (1) JP2013193025A (en)
TW (1) TW201347826A (en)
WO (1) WO2013141070A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6155490B2 (en) * 2013-12-20 2017-07-05 日本アイ・ティ・エフ株式会社 Deposition equipment
JP2016022415A (en) * 2014-07-18 2016-02-08 日本バルカー工業株式会社 Water-proof ventilation member having water-proof ventilation film made of nonwoven fabric layer containing polytetrafluoroethylene fiber and adhesive layer and usage of the same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001170461A (en) * 1999-10-07 2001-06-26 Daikin Ind Ltd Air filter medium, air filter pack and air filter unit using the same, and method for manufacturing air filter medium

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001170461A (en) * 1999-10-07 2001-06-26 Daikin Ind Ltd Air filter medium, air filter pack and air filter unit using the same, and method for manufacturing air filter medium

Also Published As

Publication number Publication date
JP2013193025A (en) 2013-09-30
TW201347826A (en) 2013-12-01

Similar Documents

Publication Publication Date Title
EP1878482B1 (en) Filter medium, process for producing the same, method of use thereof, and filter unit
KR101353726B1 (en) Process for production of polytetrafluoroethylene porous membrane, filter medium and filter unit
JP5012990B2 (en) Filter medium provided with porous membrane, manufacturing method thereof, filter pack, and filter unit
JP5037034B2 (en) Filter filter medium, its production method and method of use, and filter unit
TWI503163B (en) Teflon porous film and air filter filter
US6808553B2 (en) Filter medium for turbine and methods of using and producing the same
CN108136343B (en) Air filter medium, air filter module, and air filter unit
JP2000300921A (en) Air filter material and air filter unit using the same
JPH1030031A (en) Polytetrafluoroethylene porous membrane, its production, sheetlike polytetrafluoroethylene molded material and filtering material for air filter
KR20100117127A (en) Polyethylene membrane and method of its production
Xu et al. Preparation and properties of PTFE hollow fiber membranes for the removal of ultrafine particles in PM 2.5 with repetitive usage capability
JP2014124578A (en) Filtration material for filter and production method of the same
JP2006289174A (en) Suction filter filtering medium and its using method
KR101308358B1 (en) Asymmetric porous sheet, manufacturing method thereof and air purificaion filter using the same
JP2002370020A (en) Suction filter medium for turbine, its using method and manufacturing method therefor
WO2013141070A1 (en) Air filter for cvd apparatus, and cvd apparatus having same
JP2009112888A (en) Filter medium and filter bag
KR20180083999A (en) Filtering media comprising porous network of heat resistant polymer fiber for dust collection of middle-high temperature exhaust gas, and preparation method thereof
KR20200052687A (en) a filter having a super water-repellent and super oil-repellent function and a device for preparation thereof
JP6957472B2 (en) Non-woven
JP2005169167A (en) Air filter filtering medium
JP2014069115A (en) Filtration material for filter and method of producing the same
JP2002346319A (en) Suction filter medium for turbine
EP3804832A1 (en) Filter medium and filter unit including same
JP2002370009A (en) Suction filter medium for turbine and use method therefor

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13764187

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13764187

Country of ref document: EP

Kind code of ref document: A1