Quartz glass body having improved resistance against plasma corrosion, and method for production thereof

Abstract

An object of the present invention is to provide a quartz glass body, especially a quartz glass jig for plasma reaction in producing semiconductors having excellent resistance against plasma corrosion, particularly, excellent corrosion resistance against F-based gaseous plasma; and a method for producing the same. A body made of quartz glass containing a metallic element and having an improved resistance against plasma corrosion is provided that contains bubbles and crystalline phase at an amount expressed by projected area of less than 100 mm 2 per 100 cm 3 .

1. An article comprising a body made of quartz glass having improved corrosion resistance against plasma, the quartz glass containing bubbles and crystalline phase at a quantity accounting for less than 100 mm 2  in a projection area per  100 cm   3   cm 3  of the quartz glass body, and said quartz glass body having a metallic element containing surface layer having a thickness of at least 5 mm containing 0.1 to 20% by weight of a metallic element, wherein the metallic element is selected from the group consisting of Sm, Y, Zr and Ti. 
     
     
       2. An article as claimed in  claim 1 , wherein the metallic element has a boiling point higher than that of a Si fluoride. 
     
     
       3. An article as claimed in  claim 1 , wherein the metallic element is able to react with fluorine to form a fluoride compound and the fluoride compound of said metallic element having  has a boiling point that is higher than that of the fluoride compound of Si (SiF 4 ). 
     
     
       4. An article as claimed in  claim 1 , wherein the metallic element containing surface layer further comprises a second element selected from the group consisting of Sm, Eu, Yb, Pm, Pr, Nd, Ce, Tb, Gd, Ba  Ba, Mg, Y, Tin  Tm, Dy, Ho, Er, Cd, Co, Cr, Cs, Zr, Al, In, Cu, Fe, Bi, Ga and Ti. 
     
     
       5. An article as claimed in  claim 1 , wherein the metallic element is additionally applied to a surface thereof. 
     
     
       6. An article as claimed in  claim 1 , said quartz glass body having a surface roughness Ra of 0.01 to 10 μm. 
     
     
       7. An article as claimed in  claim 6 , wherein said body has a surface that is brought into contact with a plasma corrosive gas, said surface being obtained by subjecting the surface to a precision cutting treatment, or a heating and melting treatment. 
     
     
       8. An article as claimed in  claim 1 , wherein the quartz glass has an OH concentration of 100 to 2000 ppm. 
     
     
       9. An article as claimed in  claim 1 , wherein 2 mol/m 3  or less of a gas is discharged from the article when it heated in a temperature range of from room temperature to 1000° C. 
     
     
       10. An article as claimed in  claim 1 , wherein the quartz glass has an internal transmittance for a visible radiation of 50%/cm or higher. 
     
     
       11. An article as claimed in  claim 1 , wherein the body is configured to function as a jig for supporting wafers. 
     
     
       12. An article as claimed in  claim 7 , wherein said surface is subjected to said heating and melting treatment followed by a chemical etching treatment. 
     
     
       13. An article comprising a body made of quartz glass having improved corrosion resistance against plasma, the quartz glass being doped with a metallic element, the quartz glass containing bubbles and crystalline phase at a quantity accounting for less than  100  mm 2    in a projection area per  100  cm   3    of the quartz glass body, wherein the quartz glass body has a metallic element - containing layer with a predetermined thickness containing  0 . 1  to  20   %  by weight of said metallic element.   
     
     
       14. An article as claimed in  claim 13 , wherein the metallic element has a boiling point higher than that of a Si fluoride. 
     
     
       15. An article as claimed in  claim 13 , wherein the metallic element is able to react with fluorine to form a fluoride compound and the fluoride of said metallic element has a boiling point that is higher than that of the fluoride compound of Si. 
     
     
       16. An article as claimed in  claim 13 , wherein the metallic element is one or more elements selected from the group consisting of rare earth elements, Ba, Mg, Cd, Co, Cr, Cs, Zr, In, Cu, Fe, Bi, Ga and Ti. 
     
     
       17. An article as claimed in  claim 16 , wherein the quartz glass is further doped with Al. 
     
     
       18. An article as claimed in  claim 13 , wherein said metallic element is present in a concentration in a range from  0 . 1  to  20 %  by weight.   
     
     
       19. An article as claimed in  claim 13 , wherein said metallic element- containing layer is a surface layer having a thickness of at least  5  mm.   
     
     
       20. An article as claimed in  claim 18 , wherein the metallic element is additionally applied to the surface thereof. 
     
     
       21. An article as claimed in  claim 13 , said quartz glass body having a surface roughness Ra of  0 . 01  to  10  μm. 
     
     
       22. An article as claimed in  claim 13 , wherein said body has a surface that is brought into contact with a plasma corrosive gas, said surface being obtained by subjecting the surface to a precision cutting treatment, a heating and melting treatment, or a heating and melting treatment followed by a chemical etching treatment. 
     
     
       23. An article as claimed in  claim 13 , wherein the quartz glass has an OH concentration of  100  to  2000  ppm. 
     
     
       24. An article as claimed in  claim 13 , wherein  2  mol/m 3    or less of a gas are generated in a temperature range of from room temperature to  1000 ° C.   
     
     
       25. An article as claimed in  claim 13 , wherein the quartz glass has an internal transmittance for a visible radiation of  50 %/ cm or higher.   
     
     
       26. An article as claimed in  claim 13 , wherein said body has said metallic element applied to a surface thereof. 
     
     
       27. An article as claimed in  claim 13 , wherein the body is configured to function as a jig for supporting wafers.