Thanks Roger,

Piranha worked just fine. I used 70 % H2O2 and 30 % conc. H2SO4 at 100 C. 20
nm Nickel got etched in 2 minutes. Surface of silicon looks good under SEM.
Other recipe which was OK (attacked silicon a little) was 90% DI water + 5 %
HF (48% HF) + 5 % conc. HNO3. 20 nm Nickel got etched in 2 minutes. But
under SEM, the surface of silicon looks little rough.

Thanks for your suggestion.

Thanks,
Ananth Krishnan


From: "Roger Shile" 
To: "General MEMS discussion" 
Date: Mon, 23 Feb 2009 12:14:47 -0600
Subject: Re: [mems-talk] Transene Nickel etchant and Silicon
Another etchant that works well for Ni is Aluminum Etch, which contains
phosphoric and nitric acids.  If you just want to strip the Ni you can
use Piranha.

Roger Shile

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