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Cleaning anodized aluminum chemically without damage

I work for a Semiconductor Manufacturing company that uses a tool that has an anodized aluminum coated handler that moves the wafers from the storage cassette into the tool for measurement. The wafers have Titanium Nitride layer that is deposited at the previous step. We do periodic checks for particles (this is in a cleanroom environment). Here is the problem: Something got onto our handler (we suspect from the wafers) that was unusual. We need to figure out what we can use to clean the substance off of the anodized aluminum. It has to be non-abrasive and cannot damage the anodized surface. I believe acids will remove the anodized surface. 100% Isopropyl Alcohol and Methanol have been unsuccessful. Any ideas? Replacement of the part is several thousand dollars.

Nathan McCabe
Semiconductor manufacturing - Gilbert, Arizona, USA
2004

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Maybe ammonium citrate solution(5%) is something good for your problem. You can use pH 5-8 solution, but maybe neutral solution is best(pH 7).

Good luck!

Goran Budija
- Cerovski vrh Croatia
2004

An unusual solvent to try is corn oil. It dissolves an amazing number of things that alcohol won't touch. Then you can use alcohol to clean the corn oil off. Can't hurt, might help!

Tom Gallant
- Long Beach, California, USA
2004