Letter 40029

What chemical to use for Titanium Etch  

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I am looking for an etchant that will remove a one micron layer of Titanium film without any effect on the gold layer under the titanium.
Any suggestions?
Can one explain the chemistry of the etching process?
Thanks

Anil Dholakia
Electronics device developer - Jessup, Maryland

Dear Anil,

Try 0.5% HF solution. (Take necessary safety precaution). If your Ti layer has a thick oxide layer it will be while, but once the oxide layer is gone the Ti layer just crumbles you can see the H2 bubbling from the solution.

regards,

Karthik Thambidurai
- Austin, TX

You can try HF with various concentration. Since you only want to etch 1 micron, start from the low side. Plus, you can add CrO3 or HNO3 to HF. I heard acetic acid also ethces
Ti, you can give it a try.

Yi-Chung Su
metal processing - Taiwan