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 method for fabricating a part for a plasma chamber, the method comprising:
obtaining a part made out of an aluminum or aluminum alloy;
anodizing the part to form an anodized surface on the part, wherein the anodizing step is performed without a sealing step;
coating a section of the anodized surface by material comprising yttrium-containing material; and
sealing a section of the anodized surface which is not covered by the yttrium-containing coating.
2. The method of claim 1 , wherein the yttrium-containing coating is formed using atomic deposition in vacuum.
3. The method of claim 2 , wherein the yttrium-containing coating is performed while applying potential bias to the part.
4. The method of claim 3 , wherein the yttrium-containing coating is performed by evaporating a source material containing yttrium and sustaining plasma of reactive and non-reactive gas species.
5. The method of claim 4 , wherein the yttrium-containing coating has a surface roughness of Ra>1.0 μm, porosity of less than 1%, and a multi-layered structure.
6. The method of claim 1 , further comprising masking the yttrium-containing coating prior to performing the sealing.
7. The method of claim 1 , wherein the coating a section of the anodized surface by material comprising yttrium-containing material comprises:
effecting a physical deposition process to deposit source material on the section of the anodized surface, wherein the source material comprises the yttrium-containing material; and
effecting a chemical process to chemically modify the source material deposited on the anodized surface.
8. The method of claim 7 , wherein the chemical process comprises sustaining plasma in contact with the section of the anodized surface while supplying reactive and non-reactive gases to the plasma.
9. The method of claim 8 , wherein the physical deposition process comprises evaporation of the source material and condensation of the evaporated source material onto the section area of the anodized surface.
10. The method of claim 7 , wherein the non-reactive gas comprises argon and the reactive gas comprises one of oxygen and fluorine.
11. The method of claim 10 , wherein the yttrium-containing coating has a surface roughness of Ra>1.0 μm, porosity of less than 1%, and a multi-layered structure.
12. The method of claim 7 , further comprising masking the yttrium-containing coating prior to the sealing step.