Ghazal:

A simple answer to your question is no as copper doesn't produce any
volitile by-products that allow for plasma etching. Wet etch is the
preferred method but then you have a purely isotropic etch. So to maintain
profile of straight walls the only real method is sputter etch or ion
milling. This is accomplished at very low pressures using Argon to
physically remove the Cu. Unfortunately whatever masking material you use
will etch at about the same rate and in the case of photoresist even higher
rates than the Cu being etched. A better method would be to use a lift-off
technique where you define your image with negative shaped photoresist,
deposit the copper to level you want and then remove the photoresist using
acetone or some other chemistry that will dissolve photoresist. You can
contact EVG located here in Arizona or Bill Moffet at Yield Engineering
Services who are both experts on this process. Good luck

Bob Henderson
----- Original Message -----
From: "Hakemi, Ghazal" 
To: 
Sent: Thursday, January 24, 2008 2:40 AM
Subject: [mems-talk] Copper


Dear all,

I have a chemistry-related question : does copper etch away in oxygen
plasma?