The sputtered-off metal atoms can land everywhere inside the chamber, and some
can indeed redeposit on the wafer. In this case, the redeposited will be
sputtered off again along with the original metal.



   --Kirt Williams

  _____

From: Khaled Mohamed Ramadan [mailto:khaled.mohamedramadan@kaust.edu.sa]
Sent: Sunday, October 30, 2011 8:25 AM
To: kirt_williams@sbcglobal.net; General MEMS discussion
Cc: 志修 梁
Subject: Re: [mems-talk] Recipe of Ar plasma etching gold



isnt it a problem with such etching that the metal could redeposit on the
surface?

On Thu, Oct 13, 2011 at 4:12 AM, Kirt Williams 
wrote:

I've stripped off thin Au/Cr before with argon in an ion mill at 500 V and ~1
mA/cm2. You should be able to get something similar with a parallel-plate plasma
setup. I'd start with high power, which yields a high voltage. Also, use a low
argon pressure (say 2 mTorr), which makes the voltage higher and the current
lower for a constant power.

  --Kirt Williams