JP2007327350A - Member for vacuum pump and method for manufacturing same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a member for a vacuum pump having a surface of superior chemical resistance and a low friction coefficient, and a method for manufacturing the same at low cost. <P>SOLUTION: A rotor (a component of the member for the vacuum pump) is provided with a metal main body having an uneven shape and a curved shape on a surface thereof, and amorphous film formed on a part of the surface. Partially enlarged section part 11 near the surface of the rotor is provided with metal base material 12 forming a main body 1a and the amorphous film 13 formed on a surface of the base material 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing and manufacturing process for semiconductor processed products used in LSIs, solar cells, liquid crystals, and the like, and a vacuum pump member in which an anticorrosion film is formed on a vacuum pump disposed in an apparatus, and a manufacturing method thereof It is.

Various devices used in the manufacturing process of semiconductor processed products often use halogen-based gases such as fluoride, chloride, and sometimes bromide. There was a problem that the members, particularly the material of the moving parts, were severely corroded and worn out. For example, in these semiconductor processing apparatuses, a semiconductor made of Si, Ga, As, P, or the like is an object to be processed, and the process is performed in a so-called dry process in which processing is performed in vacuum or reduced pressure. Pumps are used, and rotating sliding members such as rotors are particularly parts with severe corrosion wear.
The corrosive halogen-based gas handled in these dry processes includes the following halogen and halogen compound gases.

Fluoride: BF _x , PF _x , NF _x , WF _x , WF _x , HF, F
Chloride: BCl _x , PCl _x , POCl _x , SnCl _x , TiCl _x , SiHCl _x , HCl, Cl ₂
Bromide: HBr
Other halides: Cl _x F
The subscript x here is any one of 1 to 5.

In the dry process using the above-described halogen gas or halogen compound gas, the reaction may be promoted using plasma energy. In this case, the halogen gas or halogen compound gas is easily ionized in the plasma environment to generate highly corrosive atomic or ionized F, Cl, Br, and corrodes the apparatus member to newly generate SiO _2. It is known to produce fine powdered solids such as Si ₃ N ₄ , Si, and W. For this reason, rotating sliding members such as air supply / exhaust fans and rotors of vacuum pumps are subject to thinning due to wear (erosion) as well as thinning due to chemical corrosion reaction (corrosion) in a strong corrosive environment. There was a problem that they occurred at the same time and the performance of each decreased in a short period of time. In addition, since piping members and pump casings that are joined to the vacuum pump are also subject to severe corrosion thinning, pump performance deteriorates in a short period of time, and many pumps have to be discarded because they cannot be used. I came.

  For various devices used in the dry process as described above, in order to improve the corrosion resistance and erosion resistance, the material has been changed, the coating with fluorine paint or epoxy paint, nickel plating or nitriding has been performed. Surface treatment such as treatment has been proposed. However, the method using a fluorine-based or epoxy-based anticorrosive coating is not sufficiently durable against halogen gas, and the coating film is short particularly against atomic halogen gas excited by plasma. In some cases, it deteriorated over time and lost its protective function. Nickel plating treatment shows relatively good corrosion resistance against halogen gas, etc., but if moisture is mixed into the atmosphere due to dry processing line cleaning treatment (water washing treatment) or the like, halogen will be removed from the pinhole of the plating film. There was a problem that an acidic aqueous solution containing a system gas component entered inside, selectively corroded the substrate, and peeled off the nickel plating film. The base material of the vacuum pump itself is replaced with cast iron or cast steel, but stainless steel or nickel alloy (for example, the trade name “Niresist”) having relatively high corrosion resistance is used. It is not a drastic measure because it lacks durability.

  In recent years, for such problems, for example, surface treatment techniques mainly composed of aluminum or aluminum oxide have been proposed for various apparatuses and members used in semiconductor processing processes, as shown in Patent Documents 1 to 5. ing. A member subjected to such a corrosion-resistant surface treatment is superior in halogen gas resistance as compared with a non-treated member, and has been able to significantly improve the use period.

JP 57-19371 A JP 60-63364 A JP-A-4-193966 Japanese Patent Laid-Open No. 9-10777 JP-A-10-219426

  However, the various devices used in the semiconductor processing line have improved corrosion resistance and extended the period of use due to the adoption of the above-mentioned various conventional techniques, but the degree of improvement is still small and will eventually be unavoidable due to corrosion damage. However, there is a time when it becomes unusable due to a reduction in the function of the device. In the semiconductor processing field, pumps and their associated parts that have lost their performance and function due to such corrosion and erosion have reached enormous amounts, causing a large loss for the entire industry.

  Therefore, an object of the present invention is to supply / exhaust pipes disposed in casings and pumps, as well as operating parts such as rotors and rotors of various pumps used in dry processes such as semiconductor processing equipment. A vacuum pump member formed by forming a film having excellent chemical durability and a low coefficient of friction on the surface and a manufacturing method thereof at low cost.

  The vacuum pump member of the present invention is obtained by coating an amorphous film mainly composed of carbon and hydrogen on the surface of a base material directly or through an undercoat film.

  In the vacuum pump member of the present invention, the thickness of the amorphous film is preferably in the range of 1 μm to 50 μm.

  In the vacuum pump member of the present invention, the amorphous film preferably has a hardness in the range of HV700 to 2800.

  In the vacuum pump member of the present invention, it is preferable that the arithmetic average roughness Ra of the surface of the amorphous film is 0.5 μm or less and the ten-point average roughness Rz is 2.0 μm or less.

  In the vacuum pump member of the present invention, the amorphous film is composed of carbon atoms in a range of 90 atomic% to 50 atomic% and hydrogen atoms in a range of 10 atomic% to 50 atomic%. In addition, the composition ratio of the carbon atoms and the hydrogen atoms to the amorphous film is preferably 100 atomic% or less.

  In the vacuum pump member of the present invention, the base material includes cast iron, cast steel, a simple substance of Ti, Al and alloys thereof, structural steel containing carbon and chromium as essential components, and Ni and Cr as essential components. It is preferable that it is one type of metal material selected from stainless steel and Ni-base alloy.

  In the vacuum pump member of the present invention, the undercoat film is a film having a thickness of 0.1 μm to 3 μm of at least one selected from the group consisting of Ti, W, Nb, Ta, Cr, Al, and Si, or an alloy thereof. It is preferable that

  In the vacuum pump member of the present invention, one or more elements selected from the simple substance of C, Ti, W, Nb, Ta, Cr, Al, and Si or alloys thereof are injected into the surface portion of the substrate. It is preferable to further have an injection layer formed by this.

  In the vacuum pump member of the present invention, the arithmetic average roughness Ra of the surface of the substrate is preferably 2.0 μm or less, and the ten-point average roughness Rz is 8.0 μm.

  The method for producing a vacuum pump member according to the present invention is a substrate surface processing step in which the arithmetic average roughness Ra of the substrate surface is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less. And an amorphous film coating step of coating and forming an amorphous film mainly composed of carbon and hydrogen on the base material.

  In the method for producing a vacuum pump member of the present invention, a step of forming an injection layer of an element selected from C, Ti, W, Nb, Ta, Cr, Al, Si on the surface portion of the processed base material Is preferably provided between the substrate surface processing step and the amorphous film coating step.

  As another aspect, the method for manufacturing a vacuum pump member according to the present invention is processed so that the arithmetic average roughness Ra of the surface of the substrate is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less. Substrate surface processing step, and undercoating that coats and forms an undercoat film made of a simple substance selected from C, Ti, W, Nb, Ta, Cr, Al, and Si or an alloy thereof on the surface of the processed base material A film coating step and an amorphous film coating step of coating an amorphous film mainly composed of carbon and hydrogen on the surface of the undercoat film.

  The amorphous film mainly composed of carbon and hydrogen according to the present invention exhibits excellent corrosion resistance due to its dense and chemically stable properties, and is relatively hard so that it can be damaged even if it comes into contact with small dusts. In addition, since the surface does not easily occur and the surface is relatively smooth, it is possible to expect effects such as difficulty in adhesion of dusts. Furthermore, since the amorphous film of the present invention is lipophilic (hydrophobic), it has a property that makes it difficult to physically contact halogens and halogen compounds in a vapor state that exhibits severe corrosiveness due to the presence of water vapor. Maintains excellent corrosion resistance over a long period of time. Therefore, the vacuum pump member of the present invention can be used for a semiconductor processing apparatus that emits plasma in an atmosphere of a gaseous halogen compound, thereby enabling stable operation of the entire apparatus and operation of the vacuum pump. It can be expected that the reduction of waste pumps along with the extension of the period, equipment repair costs, replacement costs, etc. will be reduced, and the production will be greatly improved and the production costs will be reduced.

  In addition, according to the method for manufacturing a vacuum pump member of the present invention, uniform film formation is possible even on vacuum pump members such as rotors and casings having complicated shapes. That is, it is possible to form an equivalent film on various vacuum pump members having different shapes.

  Below, the rotor (one of the members for vacuum pumps) which concerns on embodiment of this invention and its manufacturing method are demonstrated.

<First Embodiment>
FIG. 1 is a perspective view showing a rotor according to a first embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view of the vicinity of the surface of the rotor according to FIG.

  The rotor 1 includes a metal main body 1a having a concavo-convex shape or a curved shape on the surface, and an amorphous film 13 formed on a part of the surface. As shown in FIG. 2, a partially enlarged cross-sectional portion 11 near the surface of the rotor 1 includes a metal base 12 forming the main body 1 a and an amorphous film 13 formed on the surface of the base 12. It is the composition provided with.

Examples of the base material 12 include cast iron, cast steel, simple elements of Ti and Al and alloys thereof, structural steel containing carbon and containing chromium as an essential component, stainless steel and Ni-based alloy containing Ni and Cr as essential components, and the like. Can be mentioned. In particular, cast iron and cast steel contain a large amount of carbon, microscopically segregate into chrysanthemum, flakes, and spheres, and coexist with Fe ₃ C (cementite). Since it shows good adhesion, the amorphous film 13 can be formed in a dense state from a microstructural view. The arithmetic average roughness Ra of the surface of the substrate 12 is 2.0 μm or less, and the ten-point average roughness Rz is 8.0 μm.

  The amorphous film 13 is mainly composed of carbon and hydrogen, and has a thickness in the range of 1 μm to 50 μm. 5-20 micrometers is especially suitable. A film thinner than 1 μm does not have sufficient corrosion resistance and wear resistance, and a film thicker than 50 μm takes a long time to form a film. On the other hand, no significant improvement in film performance is observed, leading to an increase in production cost. It's not a good idea.

  The hardness of the amorphous film 13 is in the range of HV700 to 2800 in terms of micro Vickers hardness. Compared to the hardness of cast iron and cast steel (HV 130 to 200), it is extremely hard and exhibits excellent cavitation and erosion properties.

  Further, the amorphous film 13 is composed of carbon atoms in a range of 90 atomic% to 50 atomic%, hydrogen atoms in a range of 10 atomic% to 50 atomic%, and the amorphous film 13. The composition ratio of the carbon atom and the hydrogen atom with respect to is adjusted to be 100 atomic% or less. The amorphous film 13 preferably has a hydrogen content of 10 atomic% to 50 atomic% and the remainder is made of carbon. Furthermore, it is less susceptible to large thermal expansion and mechanical deformation, and is softer than an artificial diamond film, but has excellent adhesion and ductility, and has an amorphous state with a hydrogen content of 10 atomic% to 35 atomic%. The film 13 may be used. Note that an amorphous film having a hydrogen content of less than 10 atomic% generates a large internal stress at the time of film formation, so that it is difficult to form a thick film (10 μm or more), and although it is hard, it has poor ductility. There is a tendency to peel off due to slight deformation of the substrate. On the other hand, if the hydrogen content is larger than 50 atomic%, the hardness and mechanical strength of the amorphous film 13 are lowered, which is not preferable.

  Further, the arithmetic average roughness Ra of the surface of the amorphous film 13 is 0.5 μm or less, and the ten-point average roughness Rz is 2.0 μm or less. Therefore, since it is a smooth surface, solid foreign substances are in a state where it is difficult to physically adhere.

  Such an amorphous film 13 is dense and is not corroded at all even when immersed in an aqueous solution of acid, alkali, etc., and has no pores, so that only the pores of the substrate are preferentially corroded. There is no occurrence of pitting corrosion. The amorphous film 13 formed on the surface of the substrate 12 is used at less than 400 ° C. This is because at 400 ° C. or higher, it may be decomposed into carbon dioxide or water. Since the specific gravity is about 1.7 to 1.8, even if the above-described disassembly or separation occurs in the rotor 1 that rotates at high speed, the rotation is hardly affected. It is possible to continue the operation of the pump stably without breaking down. In addition, the amorphous surface mainly composed of carbon and hydrogen is usually oleophilic (hydrophobic). However, as a modification, N or Si is injected to change the surface to hydrophilic. The surface function can be controlled and used depending on the type.

  Next, the manufacturing method of the member 1 for vacuum pumps is demonstrated for every process.

(1: Finishing process of substrate surface)
On the surface of the base material 12 for forming the amorphous film 13, the arithmetic average roughness Ra is 0.5 μm or less and the ten-point average roughness Rz is 2.0 μm or less by mechanical, chemical and electrochemical methods. Finish with a mirror surface of If such surface finishing is not performed, the surface of the base material 13 is rough, and thus projections and the like may exist. Therefore, when the thickness of the amorphous film 13 formed on the surface of the base material 12 is relatively thin as 10 μm, the amorphous film 13 in the portion where the protrusion is present may be destroyed at an early stage or may be a starting point of corrosion. There is.

  When mechanically polishing, the arithmetic average roughness Ra is set to about 1 to 3 μm using a fine-grained # 600 polishing belt, and then surface projections are removed by lapping or buffing to obtain a ten-point average roughness. The thickness Rz can be finished to 0.8 or less. In addition, if the surface after finishing the fine abrasive belt is subjected to a chemical polishing method (for example, a mixed solution of nitric acid, hydrochloric acid, phosphoric acid, etc.) or an electrolytic polishing method is applied in these polishing solutions using the substrate 12 as an anode, arithmetic A mirror surface having an average roughness Ra of 0.1 μm and a ten-point average roughness Rz of 0.5 μm or less is obtained, and a particularly suitable pretreatment surface can be formed. However, when the thickness of the amorphous film 13 is 10 μm to 50 μm, the amorphous film 13 having good adhesion and performance can be formed only by mechanical polishing (arithmetic average roughness Ra is 1 to 3 μm). Since the surface roughness of the amorphous film is less affected by the roughness of the base material and tends to be smoothed, it is not particularly necessary to define the finishing degree.

(2: Amorphous film formation process)
Next, the process of forming an amorphous film on the surface of the substrate 12 that has undergone the above-described finishing process will be described. FIG. 3 is a schematic configuration diagram of an apparatus for forming an amorphous film. This apparatus includes a grounded reaction vessel 2, an organic gas introduction device (not shown) for film formation and a reaction vessel connected to the internal space of the reaction vessel 2 via valves 7a and 7b, respectively. A high-voltage pulse is applied to the conductor 3 connected to the base 12 of the vacuum pump member 1 disposed at a predetermined position in the reaction vessel 2 through the introduction terminal 9 and a vacuum device (not shown) for evacuation. A high voltage pulse generating power source 4 for applying, a plasma generating power source 5 for generating a plasma around the base material 12 of the vacuum pump member 1 by applying a high frequency to the conductor 3 via the high voltage introducing portion 9; In order to share the application of the pulse and the high frequency with one conductor 3, it is provided between the high voltage pulse generating power source 4 and the plasma generating power source 5 and is electrically connected to the high voltage introducing unit 9. Riding device 6 and reaction volume And a ground wire 8 connected 2 and the surface electrical.

  In order to form the amorphous film 13 on the surface of the base material 12 using the apparatus having the above-described configuration, the base material 12 as an object to be processed is installed at a predetermined position, the vacuum apparatus is operated, and the valve 7b is used. After the air in the reaction vessel 2 is discharged, an organic hydrocarbon gas is introduced into the reaction vessel 2 through the valve 7a by a gas introduction device.

  Here, the kind of hydrocarbon gas which can be used in this embodiment is demonstrated. The types of gases introduced into the reaction vessel 2 are as follows, and are organic hydrocarbons composed of carbon and hydrogen and B, Si, O, Cl, etc. added thereto.

(1) Gas phase state at room temperature (18 ° C.) CH ₄ , CH ₂ CH ₂ , C ₂ H ₂ , CH ₃ CH ₂ CH ₃ , CH ₃ CH ₂ CH ₂ CH ₃
(2) Liquid phase at normal temperature C ₆ H ₅ CH ₃ , C ₆ H ₅ CH ₂ CH, C ₆ H ₄ (CH ₃ ) ₂ , CH ₃ (CH ₂ ) ₄ CH ₃ , C ₆ H ₁₂ , C ₆ H ₅ Cl
(3) Organic Si compound (liquid phase)
_{(C 2 H 5 O) 4} Si, (CH 3 O) 4 Si, (CH 3) 4Si, [(CH) 3 Si] 2 O
A compound in a gas phase at normal temperature can be introduced into the reaction vessel 2 as it is, but a compound in a liquid phase is heated to gasify it, and this vapor is supplied into the reaction vessel 2. When an amorphous film is formed using an organic Si compound, Si may be mixed into the film, but since Si is strongly bonded to carbon, it does not hinder the use in this embodiment.

  After introducing the hydrocarbon gas into the reaction vessel 2 as described above, high frequency power from the plasma generating power source 5 is applied to the substrate 12. Since the reaction vessel 2 is in an electrically neutral state by the ground wire 8, the base material 12 has a relatively negative potential. For this reason, + ions in the plasma of the introduced gas generated by the application are characterized by being generated along the shape of the negatively charged substrate 12. Furthermore, a high voltage pulse (negative high voltage pulse) from the high voltage pulse generation source 4 can be applied to the base material 12 to positively attract + ions in the plasma to the surface of the base material 12. By this operation, an amorphous film 13 having a uniform thickness can be formed on the surface of the substrate 12. In this plasma, the following phenomena (1) to (4) occur, and it is considered that an amorphous film 13 mainly composed of carbon and hydrogen is finally formed on the surface of the substrate 12. Yes.

(1) Ionization of introduced gas (hydrocarbon) (active neutral particles called radicals also exist).
(2) The ions and radicals changed from the gas collide impactively with the blade surface to which a negative voltage is applied.
(3) C—H having a low binding energy is cut by an impact at the time of collision, and C and H are polymerized, including a polymerization reaction, accompanied by a sputtering phenomenon.
(4) An amorphous film 13 containing C and H is formed on the surface of the substrate 12.

  Note that it is possible to repeat the pulse with a pulse width of 1 μSec to 10 mSec and a pulse number of 1 to multiple times. Further, the output frequency of the high frequency power of the plasma generating power source 5 can be changed in the range of several tens of kHz to several GHz. The method of forming the amorphous film 13 with the above policy is referred to herein as a high frequency plasma CVD method.

According to the above configuration, the vacuum pump member having the amorphous film 13 that exhibits a remarkable effect on the erosion resistance while preventing the adhesion of foreign matters and is resistant to impact and bending stress, and is not easily broken or peeled off. 1 and its manufacturing method can be provided. In addition, since the formation process of the amorphous film 13 is performed under conditions accompanied by heating under reduced pressure, H ₂ , N ₂ , O ₂ , H ₂ O, hydrocarbon gas, and the like contained in the rotor 1 are used. While promoting the release of gas components, the effect of the gas components released from the metallic rotor 1 when the film is once operated as a vacuum pump member can be suppressed, so a high vacuum environment in the vacuum pump It has the advantage that it becomes easy to maintain.

Second Embodiment
Next, the vacuum pump member according to the second embodiment of the present invention will be described. In addition, the part of the codes | symbols 11 and 13 of 1st Embodiment and the part of the codes | symbols 21 and 23 of this embodiment respond | correspond in order, The description may be abbreviate | omitted. FIG. 5 is a partially enlarged cross-sectional view of the vicinity of the surface of the vacuum pump member according to the second embodiment of the present invention.

  Although not illustrated, the vacuum pump member of the present embodiment has the same outer shape as a general vacuum pump member. The partially enlarged portion 21 near the surface of the vacuum pump member includes a base material 22 and an amorphous film 23 formed on the surface of the base material 22.

  The base material 22 has a base material main part 22a and an injection layer 22b formed on the surface of the base material main part 32a (surface part of the base material 32). The injection layer 22 b is formed by injecting one or more elements selected from C, Ti, W, Nb, Ta, Cr, Al, and Si into the surface portion of the base material 22. As a modification, a metal thin film may be formed between the injection layer 22 b and the amorphous film 23.

  Next, the manufacturing method of the member for vacuum pumps concerning this embodiment is demonstrated. In addition, since the finishing process of the base material 22 surface and the formation process of the amorphous film 23 are the same as those in the first embodiment, the description will be simplified, and the formation process of the injection layer 22b of the base material 22 will be described in detail.

  First, by using the apparatus of FIG. 3 described in the first embodiment, by changing the output voltage of the high voltage pulse generation source 4, ion implantation including metal is performed on the surface of the base material 22 for implantation. Layer 22b is formed. Then, an amorphous film 23 is formed on the surface of the injection layer 22b in the same manner as in the first embodiment.

In the modification described above, the apparatus shown in FIG. 3 can also be used when a metal thin film is formed between the injection layer 22 b and the amorphous film 23. For example, it can be used for forming each layer on the surface of the base material 22 or the surface under the following conditions (1) to (4).
(1) When ion implantation is focused on the surface of the base material 22: 10 to 40 kV
(2) When ion implantation and metal thin film formation are performed: 5 to 20 kV
(3) When forming a metal thin film on the substrate 22: several hundred V to several kV
(4) When metal thin film formation is focused on the base material 22 by sputtering or the like: several hundred V to several kV
Therefore, after forming a metal ion implantation or metal thin film having a strong chemical affinity with carbon such as Cr, Si, Ta, Nb, Ti on the surface or the surface of the base material 22, the amorphous film 23 is laminated thereon. It is possible.

  According to the above configuration, the same effect as that of the first embodiment is achieved, and the amorphous film 23 is formed on the base material 22 via the injection layer 22b. The adhesion of the amorphous film 23 is increased. Therefore, it is possible to provide a vacuum pump member having an amorphous film 23 that is more difficult to break or peel and a method for manufacturing the same.

<Third Embodiment>
Next, a vacuum pump member according to a third embodiment of the present invention will be described. In addition, the site | part of the codes | symbols 11-13 of 1st Embodiment and the site | parts of the codes | symbols 31-33 of this embodiment respond | correspond in order, The description may be abbreviate | omitted. FIG. 6 is a partially enlarged cross-sectional view of the vicinity of the surface of the vacuum pump member according to the third embodiment of the present invention.

  Although not shown, the vacuum pump member of the present embodiment has the same outer shape as a general vacuum pump member. A partially enlarged portion 31 in the vicinity of the surface of the vacuum pump member is formed on a metal base 32, an undercoat 34 (undercoat film) formed on the surface of the base 32, and a surface of the undercoat 34. The amorphous film 33 is provided.

  The undercoat 34 is a film having a film thickness of 0.1 to 3 μm of at least one selected from a simple substance of Ti, W, Nb, Ta, Cr, Al, and Si or an alloy thereof.

  Next, the manufacturing method of the member for vacuum pumps concerning this embodiment is demonstrated. In addition, since the finishing process of the base material 32 surface and the formation process of the amorphous film 33 are the same as those in the first embodiment, the description will be simplified and the formation process of the undercoat 34 will be described in detail.

  First, the surface of the base material 32 is finished in the same manner as in the first embodiment, and the undercoat 34 is applied to the surface of the base material 32 using one or more methods selected from an electroplating method, a CVD method, and a PVD method. Form. Then, an amorphous film 33 is formed on the surface of the undercoat 34 in the same manner as in the first embodiment.

  According to the above configuration, the same effect as that of the first embodiment is achieved, and the amorphous film 33 is formed on the base material 32 via the undercoat 34. Therefore, the amorphous film 33 is simply formed on the surface of the base material 32. The adhesion of the amorphous film 33 is increased. Therefore, it is possible to provide a vacuum pump member having an amorphous film 33 that is more difficult to break or peel off and a method for manufacturing the same.

  Hereinafter, the present invention will be specifically described with reference to examples.

Example 1
In this example, in order to investigate the tightness of the amorphous film according to the present invention, a ferroxyl test defined in JIS H 8645 was conducted as follows to check whether there were fine through-pores in the amorphous film. investigated.

(1) Base material It was set as the base material of FC200 (dimensions width 50mm x length 70mm x thickness 7mm).
(2) Formation and thickness of amorphous film As shown in Table 3 below, an amorphous film is applied to the entire surface of the base material to have a thickness in the range of 0.5 μm to 8 μm. Each specimen was formed.
(3) Test piece of another comparative example Using the above-mentioned FC200 base material as another comparative example, a test piece in which the surface of this base material was coated with Ni and Cr to a thickness of 15 μm by electroplating, and A test piece was prepared by forming a 50 mass% Ni-50 mass% Cr alloy to a thickness of 100 μm by a thermal spraying method.
(4) Feroxyl test method Specifically, the following method was used as the ferroxyl test. That is, 10 g of potassium hexacyanoferrate (III) and 15 g of sodium chloride are dissolved in 1 liter of distilled water, and this is sufficiently impregnated in a filter paper for analysis. Thereafter, the filter paper was affixed to the surface of the test piece and allowed to stand for 30 minutes, and then the filter paper was peeled off to visually determine the presence or absence of blue spots on the filter paper surface. This is because, when there are through pores in the amorphous membrane, the ferroxyl test solution penetrates, reaches the iron substrate interface and generates iron ions, and this reacts with potassium hexacyano (dish) acid, and blue on the surface of the filter paper. It can be determined by generating spots.

  Table 1 below summarizes the above contents and test results. As is apparent from the results, the amorphous films shown as comparative examples having a thin film thickness of 0.5 μm, 0.8 μm (No. 1, No. 2), Ni plating films (No. 6 to 8) In the Cr plating film (Nos. 9 to 11) and the sprayed coating specimens (Nos. 12 to 14), the occurrence of a few or many blue spots was observed. On the other hand, in the amorphous film according to the present invention (thickness of 1.0 μm or more (No. 3 to 5)), blue spots are not observed at all, there are no through pores, and there is no spelling. It was confirmed that it is rich in properties and has an excellent effect of preventing the intrusion of corrosive components.

(Example 2)
In this example, in order to investigate the corrosion resistance of the film according to the present invention against a metal material, various metal material test pieces formed with the amorphous film of the present invention mainly composed of carbon and hydrogen were used. The corrosion resistance in fluoride gas was compared with that of an Al diffusion treatment film disclosed in non-treated and prior patent documents.

(1) Test piece of Example A base material (width 20 mm × length 10 mm × thickness 5 mm) was cut out from various metal materials as shown below, and an amorphous film containing C and H as main components over the entire surface. Was formed to a thickness of 5 μm.
(A) Carbon steel (SS400)
(B) Flake graphite cast iron (FC200)
(C) Spheroidal graphite cast iron (FCD400)
(D) Chrome steel (SUS410)
(E) Stainless steel (SUS304)
(2) Test piece for comparison As a test piece for comparison, Al was applied to the untreated base materials (a) to (e) and the base materials (a) to (c) by an Al diffusion penetration method. A coated one was made. The Al concentration of the Al coating portion was in the range of 20 mass% to 32 mass%.
(3) Corrosion test apparatus and corrosion conditions FIG. 7 shows a schematic configuration diagram of the corrosion test apparatus. After the test piece 41 is left in the stainless steel tube 43 provided in the center of the electric furnace 42 (specifically, on the test piece installation base 46), the corrosive gas 44 is as shown in FIG. Flow from the left side of the stainless steel tube 43. A quartz discharge tube 45 provided in the middle of the stainless steel tube 43 is loaded with a microwave having an output of 600 W so as to promote activation of the corrosive gas. The activated corrosive gas is guided into the electric furnace, corrodes the test piece 41 placed on the test piece mounting base 46, and then is discharged from the right side of the stainless steel pipe 43 to the outside of the system. Using the corrosion test apparatus having such a configuration, a 10-hour corrosion test was performed while flowing a test piece temperature of 120 ° C., a corrosive gas CF ₄ of 150 ml / min, and O ₂ of 75 ml / min. The feature of this corrosion test is to evaluate the corrosion resistance in an environment where corrosive CF ₄ gas is excited by plasma irradiation and changes to a stronger corrosive gas.

Table 2 below summarizes the above contents and test results. As is apparent from the results, the comparative test pieces (Nos. 6 to 13) all have a large amount of corrosion, and in particular, the untreated test pieces (No. 6, 8, and 10) have 15 to 23 mg / cm. A corrosion weight loss of ² was observed. However, in the untreated specimens (Nos. 12, 13), the stainless steel has a relatively small weight loss of 3 to 9 mg / cm ² , and in the Al diffusion treated specimens (Nos. 7, 9, 11), Corrosion weight loss was reduced, and appropriate corrosion resistance was found. On the other hand, corrosion weight loss was hardly recognized in the test pieces (Nos. 1 to 5) on which the amorphous film of the present invention was formed, and excellent corrosion resistance was confirmed.

(Example 3)
In this example, as part of investigating the corrosion resistance of an amorphous film formed on the surface of a test piece of FC200 and FCD400 (width 20 mm × length 30 mm × thickness 5 mm), it was exposed to HCl and HF in a vapor state and subjected to a corrosion reaction. The state of occurrence of red rust was investigated.

(1) Test pieces of Examples and Comparative Examples The amorphous films formed on the entire surfaces of the above FC200 and FCD400 test pieces with thicknesses of 0.8 μm, 1.0 μm, 3.0 μm, and 50 μm were used.
(2) Test piece of another comparative example A test piece of the same size was used in an untreated state and the entire surface thereof formed by forming an Ni film and a Cr plating film to a thickness of 10 μm and 20 μm by electroplating, respectively. .
(3) Corrosion test method (a) Corrosion test with HCl vapor is conducted by adding 100 ml of 30% HCl aqueous solution to the lower part of a chemical experiment desiccator and suspending a test piece on top of the HCl vapor generated from the HCl aqueous solution. The method of exposure was adopted. The corrosion test temperature is 30 ° C. to 50 ° C., and the time is 96 hours.
(B) Corrosion test with HF vapor was carried out by adding 100 ml of HF aqueous solution to the bottom of an SUS316 autoclave and hanging a test piece on the top. The corrosion test temperature is 30 ° C. to 50 ° C., and the exposure time is 96 hours.

  Table 3 below summarizes the above contents and test results. As is apparent from the results, the untreated test pieces (Nos. 9 to 12) were red rusted over the entire surface, and the red rust partly suffered severe corrosive action. Moreover, in the test piece (No. 13-16) which applied Ni plating and Cr plating, a base material was corroded by the vapor | steam which penetrated into the inside through the pinhole which exists in a plating film, red rust generate | occur | produced, and also a plating layer There was a situation in which a part of was greatly “blown”. In addition, in the test pieces (No. 1 and No. 5) having an amorphous film thickness of less than 1.0 μm, red rust was observed due to the presence of pinholes. On the other hand, the amorphous film (No. 2-4, No. 6-8) having a film thickness of 1.0 μm or more according to the present invention maintained a healthy state and exhibited extremely excellent corrosion resistance. .

Example 4
In this example, the corrosion resistance of an amorphous film formed on a non-ferrous metal substrate to HCl vapor and HF vapor was investigated.

(1) Base Material Using the materials shown below as the base material, test pieces each having a width of 20 mm, a length of 30 mm, and a thickness of 1.5 mm were manufactured.
(A) Al (Alloy No. 1085 defined by JIS H 4000)
(B) Al alloy (JIS H 4000 specified alloy number 5782)
(C) Ti (one of JIS H 4600 regulations)
(D) Ti alloy (60 types specified in JIS H 4600)
(2) Test pieces of Examples and Comparative Examples Amorphous films were formed on the surface of the base material with thicknesses of 0.8 μm, 1.0 μm, 3 μm, and 50 μm, respectively, to prepare each test piece.
(3) Test piece of another comparative example The same size as the test piece of the above example, and the untreated substrate (a) to (e) and the anodized film only for the substrate (a) ( Alumite) having a thickness of 5 μm and 10 μm was prepared and used as a test piece of a comparative example.
(4) Corrosion test method The corrosion test method and conditions are the same as those in Example 3.

  Table 4 below summarizes the above contents and test results. As is apparent from the results, Al, Ti and their alloy base materials (Nos. 9 to 12) in the comparative example are not subject to red rust like iron base materials, but often generate pitting corrosion. There was a tendency to erode deeply into the interior. Further, in the test pieces (No. 13 and No. 14) in which an anodic oxide film was formed on Al, the oxide film was completely destroyed and pitting corrosion was also observed. Further, in the amorphous films (No. 1 and No. 5) having a thickness of 1.0 μm or less, since pinholes cannot be completely eliminated, the occurrence of corrosion of the base material was observed. On the other hand, in the test piece (No. 2-4, No. 6-8) which formed the amorphous film | membrane with a film thickness of 1.0 micrometer or more, there is no generation | occurrence | production of pitting corrosion and has shown the healthy state, It was confirmed that an excellent anticorrosive effect was exhibited even for Al, Ti, and alloys thereof.

(Example 5)
In this example, SS400 copper and SUS304 steel base materials were used, and the corrosion resistance and the influence of bending work were investigated when ions of various elements were implanted into the base material surface prior to the formation of the amorphous film.

(1) Substrate (a) SS400 steel: width 15 mm x length 60 mm x thickness 1.5 mm
(B) SUS304 steel: width 15 mm x length 60 mm x thickness 1.0 mm
(2) Ion implantation apparatus, types of implanted ions and test piece of this example (a) The high frequency plasma CVD apparatus disclosed in FIG. 1 was used as the ion implantation apparatus.
(B) Types of implanted ion elements: C, Ti, W, Nb, Ta, Cr, Al, Si
(C) Implanted ion concentration: 1 × 10 ¹⁴ to 1 × 10 ¹⁶ atomic concentration per cm ² (d) Amorphous film thickness: 10 μm
After performing ion implantation on the substrate under such conditions, an amorphous film having a thickness of 2 μm was formed on the surface as a test piece of this example.
(3) Test piece of comparative example As a test piece of the comparative example, both SS400 steel and SUS304 steel were subjected to a corrosion test in an untreated state.
(4) Test conditions The test conditions were the same as in Example 3. However, in this example, the test piece after the corrosion test was bent at 90 °, and the presence or absence of peeling of the amorphous film at the bent portion was examined.

  Table 5 below summarizes the above contents and test results. As is apparent from the results, the SS400 steel (No. 10) of the comparative example generated a large amount of red rust in any gas and steam corrosion test, and red rust that had already dropped off was observed, and SUS304 steel ( In No. 13), red rust and pitting corrosion were observed. On the other hand, as a result of bending the test piece on which the amorphous film was formed at 90 ° and observing the bent portion with a magnifying glass, peeling of the film was not observed in the test piece subjected to ion implantation. In the test pieces (Nos. 9 and 12) that were not subjected to ion implantation, a slight peeling of the amorphous film was observed. From this result, it was found that the adhesion between the amorphous film and the substrate was further improved by ion implantation of an element having a strong binding force with carbon as used in this example.

(Example 6)
In this example, prior to the formation of the amorphous film on the surface of the SS400 copper and SUS304 steel substrate, the corrosion resistance when various metal thin films were formed, and the adhesion of the amorphous film during bending of the substrate, investigated.

(1) Substrate (a) SS400 steel: width 15 mm x length 60 mm x thickness 1.5 mm
(B) SUS304 steel: width 15 mm x length 60 mm x thickness 1.0 mm
(2) Thin film forming apparatus and thin film type / amorphous film thickness in the test piece of this example (a) Thin film forming apparatus: high-frequency plasma CVD apparatus disclosed in FIG. 1 (b) Thin film type: Ti, W, Nb, Ta, Cr, Al, Si
(C) The thickness of the thin film formed on the surface of the base material (a) or (b) in (1) above: 10 μm
(D) Thickness of amorphous film formed on the thin film of (c): 2 μm
(3) Test piece of comparative example As a test of a comparative example, untreated SS400 steel and SUS304 steel were used.
(4) Corrosion test condition It carried out on the same conditions as Example 3. However, in this example, the test piece after the corrosion test was bent by 90 °, and the presence or absence of the strips of the amorphous film at the bent portion was examined.

  Table 6 below summarizes the above contents and test results. As is apparent from the results, the comparative example SS400 steel (No. 9) has poor corrosion resistance. It was significantly corroded by the tested gas and steam, generating a large amount of red rust, and rust loss was also observed. In addition, generation of red rust and pitting corrosion was observed in SUS304 steel (No. 12). On the other hand, the test pieces (Nos. 1 to 8, 10, and 11) on which the amorphous film was formed exhibited excellent corrosion resistance regardless of whether or not the metal thin film was applied. In addition, as a result of performing 90 degree bending processing about the test piece after a corrosion test, and confirming the peeling condition of the film | membrane of a bending part using a magnifying glass, in a test piece (No. 8, 11) without a thin film, it is a little film Was not observed at all in other test pieces. From the above, it was found that the undercoat thin film tested was effective in improving the adhesion of the amorphous film.

(Example 7)
In this embodiment, an amorphous film is formed on the surface of a rotor for a vacuum pump disposed for use in a semiconductor processing apparatus, and the result is investigated.

(1) Rotor for vacuum pump used in this example A rotor having the same configuration as the rotor shown in FIG. 1 was used as one part of the vacuum pump. The material of this rotor was FC200, and the amorphous film was formed to a thickness of 5 μm. As a comparative example, an Al203 ceramic sprayed coating having a thickness of 100 μm formed on a rotor similar to the rotor was prepared. The surface of the ceramic sprayed coating was finished to Ra = 0.5 μm to 0.8 μm. In addition, as a comparative example, reference was made to data on the deterioration in operating performance of a vacuum pump incorporating an untreated rotor that has been conventionally used.
(2) Operating conditions of vacuum pump A vacuum pump incorporating a rotor with a coating formed as described above is installed in an actual semiconductor processing apparatus, and is operated for a total of 4000 hrs. The situation of performance degradation was observed. In addition, in the exhaust gas of the vacuum pump, fluorine-based and chlorine-based gases and moisture are mixed, which is a corrosive environment.

  Table 7 below summarizes the above contents and test results. As is clear from this result, the conventional untreated rotor showed a thinning of 0.15 mm to 0.11 mm after 4000 hours of operation, and most of the Al203 sprayed coating fell off the rotor. It was. For this reason, when operating in a vacuum pump incorporating an untreated rotor and a rotor with an Al203 coating, the clearance becomes large due to the thinning of the rotor and the drop of the sprayed coating, resulting in an extremely reduced exhaust gas compression efficiency. However, the exhaust performance (1400 L / min) at the initial stage of operation decreased from about 100 L / min to about 150 L / min. On the other hand, in the rotor formed with an amorphous film, no change was observed in appearance even at 4000 hours, and the exhaust performance (1400 L / min) at the initial stage of operation decreased to 1150 ml / min. This slight decrease in exhaust performance was found to be due to an increase in clearance due to corrosion thinning on the casing side of the vacuum pump. From the above results, it was revealed that almost complete anticorrosion measures can be expected if an amorphous film is also formed on the inner surface of the casing. Note that the amorphous film formed on the rotor showed no hindrance to the rotational motion of the rotor.

  The present invention can be changed in design without departing from the scope of the claims, and is not limited to the above-described embodiments and examples. For example, in each of the above embodiments, a rotor is shown. However, a similar film can be formed on the surface of a substrate also in other liquid feed pump members (for example, an impeller, a casing, etc.). The member can also be used as one member of a liquid feed pump. Moreover, in the base material 32 in 3rd Embodiment, the layer similar to the injection layer 22b in 2nd Embodiment may be formed in the contact surface side with the undercoat 34. FIG.

  The technology of the present invention is a component used in various semiconductor processing process apparatuses, in particular, an oxidation furnace, CVD apparatus, epitaxial growth apparatus, ion implantation apparatus, diffusion furnace, reactive ion etching apparatus, plasma applied to a dry process. The present invention can be applied to etching apparatuses and piping attached to these apparatuses, supply / exhaust fans, valves, and the like.

It is a perspective view which shows the rotor which concerns on 1st Embodiment of this invention. It is a partially expanded sectional view of the surface vicinity of the rotor of FIG. It is a schematic block diagram of the apparatus used in the manufacturing process of the rotor of FIG. It is the schematic diagram used in order to demonstrate the film thickness distribution situation at the time of forming an amorphous film | membrane with respect to the S-shaped and T-shaped base material by the method which concerns on 1st Embodiment of this invention. It is a partially expanded sectional view of the surface vicinity of the rotor which concerns on 2nd Embodiment of this invention. It is a partially expanded sectional view of the surface vicinity of the rotor which concerns on 3rd Embodiment of this invention. It is the structure schematic of the corrosion test apparatus used in Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor 1a Cylindrical part 2 Reaction container 3 Conductor 4 High voltage pulse generation source 5 Power supply for plasma generation 6 Double riding device 7a, 7b Valve 8 Ground wire 9 Introduction terminal 12, 14, 22, 32 Base material 11, 21, 31 ( Partially expanded portion (near the rotor surface) 13, 15, 23, 33 Amorphous film 41 Test piece 42 Electric furnace 43 Stainless steel tube 44 Corrosive gas 45 Quartz discharge tube 46 Test piece installation base

Claims (12)

  A member for a vacuum pump, wherein the surface of a base material is coated with an amorphous film mainly composed of carbon and hydrogen directly or through an undercoat film.   The vacuum pump member according to claim 1, wherein the amorphous film has a thickness in a range of 1 μm to 50 μm.   The vacuum pump member according to claim 1 or 2, wherein the hardness of the amorphous film is in a range of HV700 to 2800.   4. The arithmetic average roughness Ra of the surface of the amorphous film is 0.5 μm or less, and the ten-point average roughness Rz is 2.0 μm or less. 5. For vacuum pumps.   The amorphous film has a composition in which the ratio of carbon atoms is in the range of 90 atomic% to 50 atomic%, the ratio of hydrogen atoms is in the range of 10 atomic% to 50 atomic%, and the carbon atoms with respect to the amorphous film. And the composition ratio of this hydrogen atom is 100 atomic% or less, The member for vacuum pumps of any one of Claims 1-4 characterized by the above-mentioned.   The base material is cast iron, cast steel, simple substance of Ti, Al and alloys thereof, structural steel containing carbon and containing chromium as an essential component, and stainless steel and Ni-based alloy containing Ni and Cr as essential components The vacuum pump member according to claim 1, wherein the vacuum pump member is a metal material selected from the group consisting of:   The undercoat film is a film having a film thickness of 0.1 μm to 3 μm of at least one selected from a simple substance of Ti, W, Nb, Ta, Cr, Al, Si or an alloy thereof. The member for vacuum pumps described in -6.   It further has an injection layer formed by injecting one or more elements selected from simple substances of C, Ti, W, Nb, Ta, Cr, Al, and Si or alloys thereof into the surface portion of the substrate. The vacuum pump member according to claim 1, wherein the member is a vacuum pump member.   The arithmetic average roughness Ra of the surface of the base material is 2.0 µm or less, and the ten-point average roughness Rz is 8.0 µm, for a vacuum pump according to any one of claims 1 to 8. Element. Substrate surface processing step for processing so that the arithmetic average roughness Ra of the surface of the substrate is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less,
A method for producing a member for a vacuum pump, comprising: an amorphous film coating step of coating an amorphous film mainly composed of carbon and hydrogen on the base material.   The step of forming an injection layer of an element selected from C, Ti, W, Nb, Ta, Cr, Al, and Si on the surface portion of the processed base material includes the base material surface processing step and the amorphous film. The method for manufacturing a member for a vacuum pump according to claim 10, wherein the method is provided between the covering step and the covering step. Substrate surface processing step for processing so that the arithmetic average roughness Ra of the surface of the substrate is 2.0 μm or less and the ten-point average roughness Rz is 8.0 μm or less,
An undercoat film coating step for coating an undercoat film made of a simple substance selected from C, Ti, W, Nb, Ta, Cr, Al, and Si or an alloy thereof on the surface of the processed base material;
A method for producing a vacuum pump member, comprising: an amorphous film coating step of coating an amorphous film mainly composed of carbon and hydrogen on the surface of the undercoat film.

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