WO2004081381A1

WO2004081381A1 - Pump

Info

Publication number: WO2004081381A1
Application number: PCT/JP2004/002858
Authority: WO
Inventors: Tadahiro Ohmi; Yasuyuki Shirai; Masafumi Kitano
Original assignee: Tadahiro Ohmi; Yasuyuki Shirai; Masafumi Kitano
Priority date: 2003-03-12
Filing date: 2004-03-05
Publication date: 2004-09-23
Also published as: US20060127245A1; JP4694771B2; TW200425237A; JP2004278308A; TWI374470B

Abstract

A vacuum pump having a high corrosion resistance is disclosed. A member constituting the vacuum pump is composed of aluminum or an aluminum alloy, and the surface of the member is subjected to a plasma oxidation treatment such as an oxidation treatment using oxygen radicals, so that a dense and smooth aluminum oxide coating film is formed thereon.

Description

Description Pump Technical Field

The present invention relates to a pump, and more particularly, to a vacuum pump used in a vacuum processing system and a method for manufacturing the same. Background art

In general, there are two types of vacuum processing systems used in the manufacture of semiconductor devices, such as a cluster type system and an inline type system. Each of these systems uses a plurality of chambers and workpieces (wafers, glass substrates). It has a moving mechanism for transferring. In these vacuum processing systems, various processes such as formation of various coatings and etching are performed on the member to be processed in a state lower than the atmospheric pressure (that is, a vacuum state) in each chamber. In this connection, each chamber constituting the vacuum processing system is provided with a plurality of vacuum pumps for exhausting the inside of the chamber. In addition, vacuum processing systems—wafers, glass substrates, etc.—increase in size as the members to be processed increase in size, and their weight tends to be too heavy to be transported by ordinary transportation means.

Recently, a plasma processing system that performs plasma oxidation or oxygen radical oxidation in a specific chamber has been proposed, and a class-type vacuum processing system is used as the plasma processing system. In such a plasma processing system, the gas to be evacuated is very reactive, so the vacuum pump itself must be made of a material that is not corroded by the highly reactive medium. In this type of processing system, various pumps such as a turbo molecular pump, a cryopump, a booster pump, a dry pump, and a scroll pump are used as an exhaust vacuum pump. These vacuum pumps include a vacuum pump member, such as a rotor, blade, shaft, gear, etc., housed in a casing having a suction port and a discharge port. Usually, the vacuum pump member constituting the vacuum pump is made of an aluminum alloy such as duralumin or stainless steel, but an aluminum alloy is preferable in terms of reducing the weight of the vacuum pump.

However, when a vacuum pump made of an aluminum alloy is used as a vacuum pump for a plasma processing system, the inner wall of the vacuum pump is exposed to a medium such as ions and other active species and corrosive gas when various gases are dissociated by plasma. Vacuum pumps made of aluminum alloys cannot be used in plasma processing systems due to corrosion. On the other hand, vacuum pumps made of stainless steel also do not have sufficient corrosion resistance to media such as active species. These problems are not limited to vacuum pumps for plasma processing systems, but can be applied to pumps that discharge corrosive media in general.

Furthermore, the anodic oxidation treatment disclosed in Japanese Patent Application Laid-Open No. 7-216589 (Patent Document 1) is applied to a vacuum pump, and the surface of a member formed of aluminum or an aluminum alloy is subjected to corrosion resistance. It has been proposed to form an alumina film (Α 1 ₂ 0 ₃₎ with.

In fact, Japanese Patent Application Laid-Open No. 2003-21062 (Patent Document 2) describes a cryopump provided with an anodized cryopanel.

However, coating of A 1 ₂ 0 ₃ which is formed by anodic oxidation treatment is basically has also the surface a film of porous become uneven. Therefore, for example, C 1-based gas, relative to F-based _{gas, HC 1, H 2 S 0} 4, reactive strong gases or chemical such as HF, corrosion resistance of the A 1 ₂ 0 ₃ coatings anodized very Low.

Also, in the A 1 ₂ 〇 ₃ coating anodized like shed in high temperature steam, is expanded by sucked moisture molecules of the membrane, it has also been possible to post-processing such as filling the voids performed.

However, even if the above-mentioned post-treatment is performed, the use of an anodized aluminum alloy for a gas exhaust vacuum pump member for a plasma apparatus, which generally performs a process at a high degree of reduced pressure, requires a certain degree of reduced pressure. It takes a very long time to reach.

This is because the oxide coating on the surface of the anodized aluminum alloy is essentially This is due to the fact that it takes more time than necessary to evacuate to a predetermined degree of vacuum due to the problem of art gas and the presence of voids formed in the film because it is porous.

Further, when the aluminum alloy was subjected to electroless nickel plated, the nickel is a catalyst, for example a gas of _{_{S i H 4, B 2 H}} 6, PH 3, A s H 3, C 1 F 3 decomposes corrosive Promotes gas and product generation. Disclosure of the invention

It is therefore an object of the present invention to provide a vacuum pump that can be used for corrosive gases in a vacuum processing system.

Another object of the present invention is to provide a compact and lightweight vacuum pump. Still another object of the present invention is to provide a pump having high corrosion resistance to highly reactive gases or chemicals.

The pump of the present invention is characterized in that a portion exposed to a medium to be discharged is made of aluminum or an aluminum alloy, and has an oxide film oxidized by a plasma treatment.

Examples of the oxide film oxidized by the plasma treatment include, for example, an oxide film oxidized by oxygen radicals generated by plasma.

According to the study of the present inventors, an oxide film formed on a surface of aluminum or an aluminum alloy by a plasma treatment, for example, oxygen radicals generated by plasma has a very dense and flat surface property. In addition, it was confirmed that there were almost no voids in the film. It was also found that the oxide film was strong and had improved corrosion resistance.

Therefore, by using a member having such a coating as a pump, in particular, a pump member that comes into contact with a highly reactive medium, the evacuation time to a predetermined degree of reduced pressure can be reduced as compared with the conventional case. It was also found that the corrosion resistance was improved. Oxidation by oxygen radicals will be described later. Is done by doing

Further, the member of the pump of the present invention may be made of aluminum or an aluminum alloy, and the surface of the vacuum pump member may have an oxide coating of aluminum or an aluminum alloy containing a trace amount of a rare gas component.

By containing a rare gas, film stress is suppressed, and adhesion and reliability are improved. Krypton (Kr) gas and xenon (Xe) are particularly preferred as the noble gas.

Furthermore, the pump member of the present invention is made of an aluminum alloy containing at least one of aluminum, magnesium, stonium, and barium, and has an oxide film on a surface of the vacuum pump member; The coating may include an aluminum oxide and at least one oxide of magnesium, strontium, or barium. The members for such a plasma processing apparatus have further improved corrosion resistance.

The aluminum alloy may contain at least zirconium, or may contain at least hafnium. When these are contained, the mechanical strength is improved.

Furthermore, it is preferable that the content of _{Fe eMn} and _{Cr rZn in the} aluminum alloy is not more than 0.01% by weight. If these metals are included, the corrosion resistance will deteriorate.

In the above, the case where aluminum or aluminum alloy is used as the base material of the vacuum pump member has been described. However, the present invention is not limited to this, and the surface of the base material formed of iron containing aluminum is subjected to plasma oxidation. An aluminum oxide film formed by the treatment or the oxygen radical oxidation treatment may be formed on the surface. In this case, a technique of forming an aluminum oxide film on the surface by selectively oxidizing aluminum contained in the base material by plasma treatment may be used. Such a base material containing aluminum includes stainless steel.

A method for forming an aluminum oxide film on the surface of a necessary part of a pump member by plasma treatment or the like is described in Japanese Patent Application No. 2003-0284766. The applied plasma processing method can be applied.

According to the present invention, a denser and flatter film is formed and the corrosion resistance is improved as compared with the case where the conventional anodizing treatment is performed. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a block diagram showing an exhaust system for implementing an embodiment of the present invention. 2 shows a back pump of the exhaust system of FIG. 1, wherein (a) is a sectional view and (b) is another sectional view.

FIG. 3 is a schematic sectional view showing a plasma processing apparatus used for the processing of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described. Referring to FIG. 1, a cluster type vacuum processing system is shown as a vacuum processing system to which the vacuum pump according to the present invention can be applied, and the vacuum processing system includes a plurality of reaction chambers (vacuum containers) 10, 1. 1, 1 and 2 and two drop chambers 13 and 14 and a transfer chamber 15 are provided.

In addition, each reaction chamber (vacuum vessel) 10, 11, 12 has one or more chambers to reduce the pressure or vacuum inside the reaction chamber (vacuum vessel) 10 1, 12. Multiple high vacuum pumps 1, 2, 3; Booth evening pumps 4a, 5a, 6a, and back pumps (dry pumps) 4b, 5 located after the high vacuum pump b, 6b are provided. In the illustrated example, the load lock chambers 13, 14, and the transfer chamber 15 also have booster pumps 7 a, 8 a, 9 a, and back pumps 7 b, 8 b, 9 b. Each is connected. Valves 22, 23, and 24 are provided between the high vacuum pumps 1, 2, and 3 and the booster pumps 4a, 5a, and 6a. There are turbo molecular pump (screw pump), cryopump, mechanical booth Yuichi pump, back pump (dry pump) and scroll pump. In the following, the back pump (Fig. 2) will be described as an example.

Here, first, the operation of the vacuum processing system shown in FIG. 1 will be described.ゥ An object to be processed, such as c, is carried into the load lock chamber 13, and the object, which is carried into the door lock chamber 13, is transferred to the transfer chamber 1 having a lopot (transport device) for transferring the object to be processed. Transferred to reaction chambers 10, 11, 12 via 5. When processed in the reaction chambers 10, 11 and 12, the workpiece is transferred from the reaction chambers 10, 11 and 12 to the mouth chamber 14 via the transfer chamber 15. Is done.

Although not shown, the reaction chambers (vacuum vessels) 10, 11, and 12 are provided with heating means, such as a gas inlet and a heater, for introducing a predetermined gas under heating. A predetermined process such as film formation is performed. These reaction chambers 10 and 1

At least one of the reaction chambers I and 12 is configured to perform a plasma oxidation process and an oxidation process using oxygen radicals. When such an oxidation treatment is performed, the gas is decomposed into the reaction chamber to generate corrosive gas, and the corrosive gas is sequentially exhausted by the illustrated multiple-stage vacuum pump. In addition, A 1 in FIG. 1 indicates a pipe between the high vacuum pumps 1, 2, and 3 and the booster pumps 4a, 5a, and 6a, and A 2 indicates a reaction chamber (vacuum vessel) 10,

The piping between I, 12 and the high vacuum pumps 1, 2, 3 is shown. R in the figure indicates a clean room.

The illustrated vacuum processing system is first placed in a standby state. In this standby state, the transfer chamber 15 and the reaction chambers (vacuum vessels) 10, 11, 12 are kept at reduced pressure or vacuum. .

In this state, a cassette containing a plurality of objects to be processed, such as a plurality of objects, is loaded into the load lock chamber 13 from the atmosphere outside the vacuum processing system, and the load lock chamber 13 is evacuated.

Next, a gate valve (not shown) between the load lock chamber 13 and the transfer cap 15 is opened, and the workpiece transfer port pot takes out one workpiece from the cassette by the transport ham. To transfer it to transfer.

Thereafter, the gate between the reaction chamber (vacuum container) 10 and the transfer chamber 15 is opened, and the object to be processed is placed on the stage in the reaction chamber (vacuum container) 10 by the transfer arm. After a predetermined process such as a film formation process, the processed object is transported. It is transferred to another reaction chamber 11, 12 or load lock chamber 14 by the transfer arm. After the treatment, it is finally transported from the mouth lock chamber 14 to the outside.

At least one of the reaction chambers 10, 11, and 12 from which an oxide layer is formed on a workpiece by plasma oxidation or oxygen radicals has high reactive gas. It is discharged to the back pump via the vacuum pump and the booth pump. The present invention may be applied only to a vacuum pump that exhausts a reactive gas, but here, the high vacuum pumps 1, 2, 3, and a booster pump provided in all the reaction chambers 1, 2, and 3 are used. 4a to 9a and back pump (dry pump) 4b to 9b are all constituted by the vacuum pump of the present invention.

2 (a) and 2 (b), the vacuum pump of the present invention will be described using back pumps 4b to 9b as an example. The illustrated vacuum pump includes a screw pump body A, which has a plurality of spiral land portions and grooves, and a pair of screw members rotating about two substantially parallel axes that mesh with each other. It has a mouth 25 and 26.

Screen screws 25, 26 are housed in casing 27, and are rotatably supported by bearings 35 at one end of shaft 28, which supports screw openings 25, 26. ing. A timing gear 30 is attached to one end of the shaft 28, and a motor (not shown) is connected to the other end. When the shaft 28 is rotated by the motor, the pair of screw rotors 25, 26 is synchronously rotated via the timing gear 30.

A suction port 31 is formed at one end of a casing 27 for accommodating both screws 25, 26, and a discharge port 3 2 (at the other end of the casing 27). Figure 2 (b)) is formed. In this example, the suction port 31 is connected to the chamber side, and the discharge port 32 is connected to the atmosphere side. The motor rotates the screens 25 and 26 in synchronism, so that gas from the chamber side is sucked in from the suction port 31 and discharged from the discharge port 32. As a result, the gas inside Exhausted. On the discharge port 32 side of the illustrated casing 27, a jacket 33 is formed in which a cavity is formed to allow cooling water to circulate. It is configured so that the heat generated by the gas based on the compression action on the two sides can be cooled.

In addition, a cover 34 is attached to one end of the casing 27 that houses the two openings 25, 26, and one end of a shaft 28 that supports one screw rotor 26. Is formed so as to protrude from the cover 34 and be directly connected to a rotating shaft of a motor described later. Further, a seal member 29 is provided between the bearing 35 and the screw rotors 25, 26.

The members of the back pump (dry pump) shown in Fig. 2 are all made of aluminum or aluminum alloy as the base material. Of these members, the rotors 25, 26, and Single 27, seal member 29, suction port 31, discharge port 32, etc. (and in some cases also shaft 28), are exposed to corrosive gases and chemicals during discharge of corrosive gases and chemicals. Is done. In this case, as the strong gas or chemical reactivity, eg, C 1-based gas, F-based _{gas, HC 1, H 2 S 0} 4, HF and the like.

By performing the treatment according to the present invention on all members constituting the back pump, it is possible to impart corrosion resistance to the entire back pump. Here, members exposed to corrosive gas, that is, Evening 25, 26, casing 27, sealing member 29, at least the gas-exposed surface of the suction port 31 and the discharge port 32 exposed to gas according to the present invention, As a result, as shown in bold lines in FIGS. 2 (a) and (b), an aluminum oxide film is formed on the surface of each component. As described above, the aluminum oxide film formed by the plasma oxidation treatment or the oxidation treatment with oxygen radical has a feature that it has no voids, is extremely dense, and has a flat surface. For this reason, high corrosion resistance can be maintained even for highly reactive gases and the like.

With reference to FIG. 3, a method of forming the above-described aluminum oxide film on the vacuum pump member using the plasma processing apparatus 1 will be described. The illustrated plasma processing apparatus 1 performs processing of a vacuum pump member 40 shown in a rectangular shape. Shall be. The plasma processing apparatus 1 has a cylindrical processing container 2 having a bottom and an open top made of, for example, an aluminum alloy, and the processing container 2 is grounded. A susceptor 3 on which a vacuum pump member 40 is placed is provided at the bottom of the processing container 2. The susceptor 3 is made of, for example, an aluminum alloy, and the heater 5 of the susceptor 3 generates heat by power supply from an AC power supply 4 provided outside the processing vessel 2. Heated to 0 ° C.

An exhaust device 41 such as a turbo molecular pump is connected to the bottom of the processing container 2 via an exhaust pipe 42, and the inside of the processing container 2 is exhausted by the exhaust device 41. A supply pipe 44 for supplying a processing gas from a processing gas supply source 43 is provided on a side wall of the processing container 2. In the present embodiment, the processing gas supply source 43 is connected to oxygen gas (02) and inert gas argon (Ar) gas supply sources 45 and 46, respectively.

A dielectric window 22 made of, for example, quartz glass is provided at an upper opening of the processing container 2 via a sealing material 21 such as an O-ring for ensuring airtightness. A processing space S is formed in the processing container 2 by the dielectric window 22.

Above the dielectric window 22, an antenna member 51 is provided. In this example, the antenna member 51 is, for example, a radial slot antenna 52 located at the lowermost surface, and a slow wave plate 53 located above the same. The slow wave plate 53 is covered to protect the slow wave plate 53. And an antenna cover 54 for cooling it.

The radial slot antenna 52 is formed of a thin disk made of a conductive material, for example, copper, and a pair of slits having an acute angle close to a right angle are formed on the disk by being arranged concentrically. ing.

At the center of the slow wave plate 53, a bump 55 that forms a part of a conical shape made of a conductive material, for example, a metal is arranged. The bump 55 is electrically connected to the inner conductor 56 a of the coaxial waveguide 56 composed of the inner conductor 56 a and the outer tube 56 b. The coaxial waveguide 56 propagates, for example, a 2.45 GHz microwave generated by the microwave supply device 57 to the antenna member 51 through the coaxial waveguide 56 through the load matching device 58. It is configured to be. Next, a plasma processing method performed in the illustrated vacuum processing system 1 will be described. Will be explained. First, a vacuum pump member 40 formed of aluminum or an aluminum alloy is placed on the susceptor 3. In this state, krypton-containing oxygen gas is supplied from a supply source 45, and plasma is generated in the processing vessel 2. Is done. In this case, the vacuum pump member 40 is maintained at a temperature of 450 ° C. or less (preferably, 150 ° C. to 250 ° C.). The plasma could be generated in the processing container 2 even when the vacuum pump member 40 was kept at room temperature (eg, 23 ° C.). When the plasma was generated, oxygen radicals were generated in the processing chamber 2, and the surface of the vacuum pump member 40 was oxidized by the oxygen radicals to form an oxide film.

Thus, oxide film produced by the oxidation treatment using oxygen radicals has no void was confirmed to be extremely dense and moreover the surface is coated flat A 1 ₂ 0 _3. This is because the surface of the aluminum or aluminum alloy was modified by oxygen radical.

The reaction formula at this time is as follows.

2 A 1 + 30 * → A 1 ₂ 0 ₃

Furthermore, when forming a vacuum Bonn flop member 40 by an aluminum alloy containing magnesium (Mg), by oxygen radicals, oxide film containing a large amount of MgO and (A 1 ₂ 0 ₃₎ can be formed on the aluminum alloy surface Was. Thus, the oxide film containing Mg0 can improve corrosion resistance and strength. In this case, the content of magnesium is desirably from 0.5% by weight to the maximum amount of solid solution (about 6.0% by weight). When oxygen radicals are generated by converting oxygen gas containing krypton into plasma, the content of magnesium can be as small as 0.5% by weight to 1.0% by weight. I got it.

As the aluminum alloy, an aluminum alloy containing stotium, barium, zirconium, and hafnium in addition to magnesium described above can be used. By forming an oxide film containing a large amount of SrO and Ba0 on the aluminum alloy surface, the corrosion resistance and strength of the vacuum pump member 40 could be improved. In addition, when aluminum alloy containing about 0.1 to 0.15% by weight of zirconium is used, the vacuum pump member 40 having high corrosion resistance and high mechanical strength by suppressing alloy grain growth can be formed. Furthermore, it has been confirmed that even if an aluminum alloy containing 0.1 to 0.15% by weight of hafnium is used, a vacuum pump member having high corrosion resistance and high mechanical strength can be obtained by suppressing alloy grain growth. .

On the other hand, aluminum alloys often contain Fe, Mn, Cr, and Zn, and these usually lower the corrosion resistance of aluminum alloys. It is desirably 1% by weight or less. Note that Fe, Mn, Cr, and Zn in the aluminum alloy were removed by reducing the vacuum pump member 40 with hydrogen at a temperature of 450 ° C or less before performing the oxidation treatment. it can.

In the case where oxygen radicals are generated by plasma, the case where krypton (Kr) is mixed into an oxygen-containing gas to generate plasma has been described.However, by mixing krypton gas, it is excited to a high energy state. This is because the crypton collides with oxygen molecules and can easily generate two oxygen radicals.

In generating oxygen radicals, oxygen plasma may be generated using a gas obtained by mixing argon (Ar) gas with an oxygen-containing gas. When argon gas is used, argon gas is easy to handle and inexpensive, so that the vacuum pump member 40 can be actually easily and inexpensively processed.

As described above, when a plasma is generated using a rare gas such as krypton or argon, plasma oxidation treatment, for example, oxidation treatment with oxygen radicals is performed. Gas components will be included. This rare gas component suppresses the film stress of the oxide film and helps to improve the adhesion and reliability.

As the plasma source for generating oxygen plasma, the plasma processing apparatus 1 described above used microwave plasma having a frequency of 2.45 GHz. Since the microwave plasma is a high-density and gentle plasma having a relatively low Vdc, the surface of the vacuum pump member 40 is radically oxidized without damaging the surface of the aluminum or aluminum alloy. An object film can be formed. Furthermore, in the example described above, only the case where the vacuum pump member 40 is formed of aluminum or an aluminum alloy has been described. However, the present invention is not limited to this, and is constituted by stainless steel containing aluminum. Similar results were obtained when an aluminum oxide film was formed on the surface of the vacuum pump member.

Further, the pump to which the present invention is applied is not limited to the pump shown in FIG. 2 and is generally applied to a pump exposed to a highly corrosive gas or chemical solution. It is effective to apply a film containing aluminum oxide to the surface. Industrial applicability

INDUSTRIAL APPLICABILITY The pump according to the present invention can be used as a vacuum pump for evacuating each chamber in a vacuum processing system used for manufacturing semiconductor devices and the like.

Claims

The scope of the claims

1. A pump having a suction port for a gas to be evacuated and a discharge port for the gas, wherein a member exposed to the gas is made of aluminum or an aluminum alloy, and the member is an oxide oxidized by plasma processing. A pump having a coating as a surface layer.

2. A pump having a suction port for a medium to be discharged and a discharge port for the medium, wherein a member exposed to the medium is made of aluminum or an aluminum alloy, and the member is an oxide oxidized by oxygen radicals. A pump having a coating as a surface layer.

3. The pump according to claim 1, wherein the surface layer is an oxide film of aluminum or aluminum alloy containing a trace amount of a rare gas component.

4. The pump according to claim 3, wherein the rare gas component is krypton or xenon.

5. A pump having a suction port for a gas to be evacuated and a discharge port for the gas, wherein the member exposed to the gas is selected from the group consisting of magnesium, strontium, barium, zirconium, and hafnium. An aluminum alloy containing at least one selected from the group consisting of: an aluminum alloy, the member having an oxide coating as a surface layer of a portion exposed to the gas, wherein the oxide coating contains an aluminum oxide; Pump.

6. The pump according to claim 5, wherein the oxide film further includes at least one oxide of magnesium, strontium, barium, zirconium, and hafnium.

7. The aluminum alloy according to any one of claims 1 to 5, wherein the content of Fe, Mn, Cr, and Zn is 0.01% by weight or less. pump.

8. A member used in a vacuum processing system and exposed to a medium to be evacuated from the vacuum system is made of aluminum or an aluminum alloy, and a portion exposed to the medium has an oxide oxidized by plasma processing. Coating with surface layer A vacuum pump comprising:

9. The member used in the vacuum processing system and exposed to the medium to be evacuated from the vacuum processing system is made of aluminum or an aluminum alloy, and the part exposed to the medium is oxidized by oxygen radicals. A vacuum pump having an oxide film as a surface layer.

10. The vacuum pump according to claim 8, wherein the surface layer is an oxide film of aluminum or an aluminum alloy containing a trace amount of a rare gas component.

11. The vacuum pump according to claim 10, wherein the rare gas component is krypton or xenon.

12. A vacuum pump used in a vacuum processing system and at least partially exposed to a medium to be evacuated from the vacuum system, wherein magnesium, strontium, barium, zirconium, and A vacuum pump comprising an aluminum alloy containing at least one selected from the group consisting of: hafnium, and further comprising an aluminum oxide as a surface layer.

13. The vacuum pump according to claim 12, wherein the surface layer contains at least one oxide of magnesium, strontium, barium, zirconium, and hafnium.

14. The vacuum according to claim 12, wherein the aluminum alloy has a content of Fe, Mn, Cr, and Zn of 0.01 wt% or less. pump.

15. The vacuum pump according to any one of claims 8 to 14, wherein the vacuum processing system is a plasma processing apparatus that performs plasma processing.

16. The vacuum pump according to any one of claims 8 to 15, wherein the medium is a highly reactive gas or chemical solution.

17. A pump having a suction port for a medium to be discharged and a discharge port for the medium, wherein a pump member exposed to the medium has a base material formed of iron containing aluminum and has a plasma processing. A pump having, as a surface layer, an aluminum oxide film oxidized by the above.

18. A member having a suction port for a medium to be discharged and a discharge port for the medium, and a member exposed to the medium has a base material formed of iron including aluminum, and is oxidized by oxygen radical. A pump having the aluminum oxide film as a surface layer.

19. The pump according to claim 17, wherein the base material is stainless steel containing 3 to 7% by weight of aluminum.

20. The pump according to any one of claims 17 to 19, wherein the surface layer is an oxide film of the aluminum containing a trace amount of a rare gas component.

21. The pump according to claim 17, wherein the aluminum oxide film is formed on at least a surface of a portion exposed to the medium.

22. A member used in a vacuum processing system and at least partially exposed to a medium to be evacuated from the vacuum processing system has a base material formed of iron including aluminum, and is oxidized by plasma processing. A vacuum pump comprising the aluminum oxide film as a surface layer.

23. A member used in a vacuum processing system and at least partially exposed to a medium to be evacuated from the vacuum processing system has a base material formed of iron including aluminum, and has been oxidized by oxygen radicals. A vacuum pump having the aluminum oxide film as a surface layer.

24. The vacuum pump according to claim 22, wherein the base material is stainless steel containing 3 to 7% by weight of aluminum.

25. The vacuum pump according to any one of claims 22 to 24, wherein the surface layer is an oxide film of the aluminum containing a trace amount of a rare gas component.

26. The vacuum pump according to any one of claims 22 to 25, wherein the aluminum oxide coating is formed on at least a surface of a portion exposed to the medium.

27. A vacuum pump having a base material formed of iron containing aluminum and having, as a surface layer, an oxide film of the aluminum oxidized by oxygen radicals.

28. The vacuum pump according to claim 27, wherein the aluminum oxide film is formed on at least a surface of a portion exposed to the medium.

29. In a method for manufacturing a vacuum pump member exposed to a medium exhausted from a vacuum system, the vacuum pump member is formed of a metal containing aluminum, and the vacuum pump member is subjected to a plasma treatment or an oxygen radical atmosphere. A method of manufacturing a vacuum pump member, comprising forming an oxide film of aluminum.

30. The method according to claim 29, wherein the metal is aluminum or an aluminum alloy.

31. The method for manufacturing a vacuum pump member according to claim 29, wherein the metal is stainless steel containing 3 to 7% by weight of aluminum.

32. A pump having a base material formed of iron containing aluminum and having, as a surface layer, an oxide film of the aluminum oxidized by plasma treatment.

33. A pump having a base material formed of iron containing aluminum and having, as a surface layer, an oxide film of the aluminum oxidized by oxygen radicals.