Coating packaged chamber parts for semiconductor plasma apparatus
An advanced coating for parts used in plasma processing chamber. The advanced coating is formed over an anodized surface that has not been sealed. After the coating is formed, the coated area is masked, and the remaining anodized surface is sealed. The porous and rough structure of the anodized but un-sealed aluminum enhances adhesion of the coating. However, to prevent particle generation, the exposed anodized surface is sealed after formation of the coating. The coating can be of yttria, formed by plasma enhanced atomic deposition techniques which results in a dense and smooth coating.
1. A part to be used inside a plasma processing chamber, comprising:
a part body having an anodized exterior surface;
a yttrium-containing coating formed directly on an unsealed section of the anodized exterior surface; and,
a sealant formed on a section of the anodized exterior surface which is not covered by the yttrium-containing coating.
2. The part of claim 1 , wherein the anodized exterior surface has roughness of 4 μm<Ra<12 μm.
3. The part of claim 1 , wherein the yttrium-containing coating comprises a yttria coating.
4. The part of claim 3 , wherein the yttria coating has a surface roughness of Ra>1.0 μm, porosity of less than 1%, and a multi-layered structure.
5. The part of claim 1 , wherein the part comprises a showerhead, the yttrium-containing coating comprises a yttria coating, and wherein the yttria coating has a surface roughness of Ra>1.0 μm, porosity of less than 1%, and a multi-layered structure.
6. The part of claim 1 , wherein the yttrium-containing coating has a random crystal orientation created by plasma enhanced physical vapor deposition.
7. The part of claim 1 , wherein the yttrium-containing coating comprises one of Y 2 O 3 or YF 3 .
8. The part of claim 1 , wherein the sealant comprises hydrated anodized aluminum.
9. The part of claim 1 , wherein the sealant comprises anodized aluminum impregnated with a sealant material.
10. The part of claim 5 , wherein the unsealed section of the anodized exterior surface has roughness of 12 μm>Ra>4 μm.
11. The part of claim 1 , wherein the sealant comprises one of: Teflon, nickel acetate, cobalt acetate, sodium or potassium dichromate.
12. The part of claim 1 , wherein:
the unsealed section of the anodized exterior surface has roughness of 12 μm>Ra>4 μm;
the yttrium-containing coating comprises a yttria coating; and,
the yttria coating has a surface roughness of Ra>1.0 μm and porosity of less than 1%.
13. The part of claim 12 , wherein the sealant comprises one of hydrated anodized aluminum or anodized aluminum impregnated with a sealant material.
14. The part of claim 13 , wherein the sealant material comprises one of: Teflon, nickel acetate, cobalt acetate, sodium or potassium dichromate.
15. The part of claim 1 , wherein:
the unsealed section of the anodized exterior surface has roughness of 12 μm>Ra>4 μm;
the yttrium-containing coating comprises one of Y 2 O 3 or YF 3 ; and,
the sealant comprises one of hydrated anodized aluminum or anodized aluminum impregnated with a sealant material.
16. The part of claim 15 , wherein the sealant material comprises one of: Teflon, nickel acetate, cobalt acetate, sodium or potassium dichromate.
17. A part of claim 15 , wherein the yttrium-containing coating comprises one of Y 2 O 3 or YF 3 formed by process of plasma enhanced physical vapor deposition.
18. The part of claim 17 , wherein the yttrium-containing coating has a surface roughness of Ra>1.0 μm and porosity of less than 1%.