Pump

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.

1 . A pump having an inlet port for a gas to be exhausted and a discharge port for said gas, wherein a member exposed to said gas is made of aluminum or an aluminum alloy and said member has, as a surface layer, an oxide coating film oxidized by a plasma treatment.  
   
   
       2 . A pump having an inlet port for a medium to be exhausted and a discharge port for said medium, wherein a member exposed to said medium is made of aluminum or an aluminum alloy and said member has as a surface layer an oxide coating film oxidized by oxygen radicals.  
   
   
       3 . A pump according to  claim 1  or  2 , wherein said surface layer is specified by the oxide coating film of the aluminum or aluminum alloy containing a very small amount of a noble gas component.  
   
   
       4 . A pump according to  claim 3 , wherein said noble gas component is krypton or xenon.  
   
   
       5 . A pump having an inlet port for a gas to be exhausted and a discharge port for said gas, wherein a member exposed to said gas is made of an aluminum alloy containing at least one selected from the group consisting of magnesium, strontium, barium, zirconium, and hafnium, said member has an oxide coating film as a surface layer of a portion exposed to said gas, and said oxide coating film contains an oxide of aluminum.  
   
   
       6 . A pump according to  claim 5 , wherein said oxide coating film further contains at least one oxide among respective oxides of magnesium, strontium, barium, zirconium, and hafnium.  
   
   
       7 . A pump having an inlet port for a gas to be exhausted and a discharge port for said gas, wherein a member exposed to said gas is made of an aluminum alloy and said member has, as a surface layer, an oxide coating film oxidized by a plasma treatment, 
 said aluminum alloy containing 0.01 wt % or less of each of Fe, Mn, Cr, and Zn.    
   
   
       8 . A vacuum pump for use in a vacuum processing system, wherein a member exposed to a medium to be exhausted from said vacuum processing system is made of aluminum or an aluminum alloy and, further, has as a surface layer an oxide coating film oxidized by a plasma treatment at a portion exposed to said medium.  
   
   
       9 . A vacuum pump for use in a vacuum processing system, wherein a member exposed to a medium to be exhausted from said vacuum processing system is made of aluminum or an aluminum alloy and, further, has as a surface layer an oxide coating film oxidized by oxygen radicals at a portion exposed to said medium.  
   
   
       10 . A vacuum pump according to  claim 8  or  9 , wherein said surface layer is the oxide coating film of the aluminum or aluminum alloy containing a very small amount of a noble gas component.  
   
   
       11 . A vacuum pump according to  claim 10 , wherein said noble gas component is krypton or xenon.  
   
   
       12 . A vacuum pump for use in a vacuum processing system, at least portion of which is exposed to a medium to be exhausted from said vacuum processing system, wherein the portion exposed to said medium is made of an aluminum alloy containing at least one selected from the group consisting of magnesium, strontium, barium, zirconium, and hafnium and further includes an oxide of aluminum as a surface layer.  
   
   
       13 . A vacuum pump according to  claim 12 , wherein said surface layer contains at least one oxide selected from the group consisting of magnesium, strontium, barium, zirconium, and hafnium.  
   
   
       14 . A vacuum pump according to  claim 12 , wherein said aluminum alloy contains 0.01 wt % or less of each of Fe, Mn, Cr, and Zn.  
   
   
       15 . A vacuum pump according to  claim 8  or  9 , wherein said vacuum processing system is a plasma processing system that performs a plasma treatment.  
   
   
       16 . A vacuum pump according to  claim 8  or  9 , wherein said medium is a reactive gas or chemical liquid.  
   
   
       17 . A pump having an inlet port for a medium to be exhausted and a discharge port for said medium, wherein a pump member exposed to said medium has a base material formed of iron containing aluminum and has as a surface layer a coating film of an oxide of said aluminum oxidized by a plasma treatment.  
   
   
       18 . A pump comprising an inlet port for a medium to be exhausted and a discharge port for said medium, wherein a member exposed to said medium has a base material formed of iron containing aluminum and has as a surface layer a coating film of an oxide of said aluminum oxidized by oxygen radicals.  
   
   
       19 . A pump according to  claim 17  or  18 , wherein said base material is a stainless steel containing 3 to 7 wt % aluminum.  
   
   
       20 . A pump according to  claim 17  or  18 , wherein said surface layer is the coating film of the oxide of the aluminum containing a very small amount of a noble gas component.  
   
   
       21 . A pump according to  claim 17  or  18 , wherein said coating film of the oxide of the aluminum is formed on a surface of at least a portion exposed to said medium.  
   
   
       22 . A vacuum pump for use in a vacuum processing system wherein a member at least part of which is exposed to a medium to be exhausted from said vacuum processing system has a base material composed of iron containing aluminum and has as a surface layer a coating film of an oxide of said aluminum oxidized by a plasma treatment.  
   
   
       23 . A vacuum pump for use in a vacuum processing system wherein a member at least part of which is exposed to a medium to be exhausted from said vacuum processing system has a base material formed of iron containing aluminum and has as a surface layer a coating film of an oxide of said aluminum oxidized by oxygen radicals.  
   
   
       24 . A vacuum pump according to  claim 22  or  23 , wherein said base material is a stainless steel containing 3 to 7 wt % aluminum.  
   
   
       25 . A vacuum pump according to  claim 22  or  23 , wherein said surface layer is the coating film of the oxide of the aluminum containing a very small amount of a noble gas component.  
   
   
       26 . A vacuum pump according to  claim 22  or  23 , wherein said coating film of the oxide of the aluminum is formed on a surface of at least a portion exposed to said medium.  
   
   
       27 . A vacuum pump comprising a base material composed of iron containing aluminum and a surface layer formed by a coating film of an oxide of said aluminum oxidized by oxygen radicals.  
   
   
       28 . A vacuum pump according to  claim 27 , wherein said coating film of the oxide of the aluminum is formed on a surface of at least a portion exposed to said medium.