High purity metallic top coat for semiconductor manufacturing components
A method for coating a component for use in a semiconductor chamber for plasma etching includes providing a component for use in a semiconductor manufacturing chamber, loading the component into a deposition chamber, cold spray coating a metal powder onto the component to form a coating on the component, and anodizing the coating to form an anodization layer.
1. A method comprising:
cold spray coating a metal powder onto an article to form a coating on the article; and
anodizing the coating to form an anodization layer having a thickness of about 2-10 mil, wherein the anodization layer comprises a plurality of columnar nanopores having a diameter of about 10-50 nm, wherein at least a portion of the anodization layer has a porosity of about 40-50%, and wherein anodizing the coating comprises:
applying a first current density during a start of the anodizing to form a low porosity layer portion of the anodization layer, the low porosity layer portion having a porosity that is less than the porosity of about 40-50%; and
applying a second current density that is lower than the first current density during a remainder of the anodizing to form a porous columnar layer portion of the anodization layer, the porous columnar layer portion comprising the plurality of columnar nanopores and having the porosity of about 40-50%.
2. The method of claim 1 further comprising performing chemical mechanical polishing (CMP) of the coating to cause the coating to have an average surface roughness of less than about 20 micro-inch prior to anodizing the coating.
3. The method of claim 1 , wherein the metal powder being cold spray coated onto the article has a velocity in a range from about 100 m/s to about 1500 m/s, and wherein a carrier gas used to propel the metal powder has a gas pressure of about 50-1000 psi and a gas temperature of about 120-200 degrees C.
4. The method of claim 1 , wherein the metal powder is sprayed via a carrier gas of Argon.
5. The method of claim 1 , further comprising:
forming a barrier layer between the article and the coating by heating the article after the cold spray coating to a temperature in a range from about 200 degrees C. to about 1450 degrees C. for more than about 30 minutes, wherein the barrier layer has a thickness of about 0.5-5.0 microns.
6. The method of claim 5 , wherein the article comprises a first one of Aluminum or Titanium, wherein the coating comprises a second one of Aluminum or Titanium, and wherein the barrier layer comprises a solid solution of Aluminum and Titanium.
7. The method of claim 1 , wherein the coating has a thickness in a range from about 0.1 mm to about 40 mm.
8. The method of claim 1 , wherein the article comprises at least one of Aluminum, an Aluminum alloy, stainless steel, Titanium, a Titanium alloy, Magnesium, or a Magnesium alloy.
9. The method of claim 1 , wherein the metal powder comprises at least one of Aluminum, an Aluminum alloy, Copper, or a Copper alloy.
10. The method of claim 1 , wherein the article is a showerhead of a semiconductor manufacturing chamber, a cathode sleeve, a sleeve liner door, a cathode base, a chamber line, or an electrostatic chuck base.
11. The method of claim 1 , further comprising:
roughening a surface of the article to an average surface roughness of about 120 micro-inches.
12. The method of claim 1 , further comprising:
loading the article onto a stage in a deposition chamber, wherein the stage is movable in up to three dimensions; and
moving the stage during the cold spray coating to coat a plurality of portions of the article.
13. The method of claim 1 , wherein the anodizing is performed using a bath of oxalic acid.
14. The method of claim 1 , further comprising:
deoxidizing the coating using a nitric acid bath prior to performing the anodizing.
15. The method of claim 1 , wherein the cold spray coating is performed in a vacuum having a pressure of less than about 0.1 mTorr, and wherein particles of the metal powder have a diameter of about 1-50 microns.
16. The method of claim 1 , wherein the metal powder comprises a mixture of a first metal and a second metal, and wherein performing the cold spray coating comprises adjusting a percentage of the first metal and the second metal to cause the coating to have a gradient of the first metal and the second metal.
17. The method of claim 1 , wherein the coating is devoid of oxide inclusions.
18. The method of claim 1 , wherein the metal powder comprises at least one of Titanium or a Titanium alloy.
19. The method of claim 1 , wherein the metal powder comprises at least one of Niobium, a Niobium alloy, Zirconium, or a Zirconium alloy.
20. The method of claim 1 , wherein about 1-50% of the coating is consumed to form the anodization layer.