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Specialty Chemistry Forums => Materials and Nanochemistry forum => Topic started by: thedoors24 on May 28, 2014, 02:55:12 PM

Title: Wet etching of Indium
Post by: thedoors24 on May 28, 2014, 02:55:12 PM

Hi,

I want to build up a microfabrication process that includes Ti, Au, Cu and In. In the process I need to wet etch the Ti and Cu with CR7 (Cyantek) and 10:1 (H2O and HF). The thing is that I will have to immerge the Indium layer in these two etchants. I know that HCL slowly etches Indium but I don't know if CR7 and HF do as well. I hope they don't.

Can you guys help me out?

Regards,
Xavier

Title: Re: Wet etching of Indium
Post by: Arkcon on May 28, 2014, 05:13:39 PM

I don't expect a weak acid like HF to affect a metal like iridium.  I don't recognize the trade item CR&, can you tell us what chemicals it contains?

Title: Re: Wet etching of Indium
Post by: thedoors24 on May 28, 2014, 11:22:24 PM

First, it is Indium not Iridium  ;).

The CR7 composition is: Ceric Ammonium Nitrate 9% and Perchloric Acid 6%.

Thank you very much!

Title: Re: Wet etching of Indium
Post by: Arkcon on May 29, 2014, 05:46:02 AM

That makes the problem easier. ;)  I have etched away the Inconel coating of a first surface mirror with 10% Ceric Ammonium Nitrate in 0.1 N Nitric acid, so the CR7 may attack it..

Title: Re: Wet etching of Indium
Post by: thedoors24 on May 29, 2014, 09:40:56 AM

The coating of the mirror was made of Indium? Do you remember what was the etch rate? (slow, fast ?)

Title: Re: Wet etching of Indium
Post by: Arkcon on May 29, 2014, 02:15:50 PM

Opps, I went and checked, and it seems Inconel alloy contains no Indium.  Sorry about my confusion, but I guess I have no information for you.  :o