Ashwini,

        Because RIE is a much higher energy than amorphous plasma you can get
problems.  One would be sputtering of any exposed metal which could coat the
chamber walls and redeposit later.  A second could be aggressive etching of the
exposed surfaces using the aluminum as a mask.  If you are only using Oxygen
this should be a low level problem.  Bill Moffat

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org] On
Behalf Of Alexandre BOE
Sent: Monday, July 06, 2009 8:58 AM
To: General MEMS discussion
Subject: Re: [mems-talk] Using DRIE chamber for Photoresist Ashing

Dear Ashwini,

I have previously etched some silicon wafer using DRIE in a STS tool with some
metal exposed just at the end of the etching, perhaps about 1 min. I always
performed a cleaning just after this step (O2 plasma and sometimes manually) and
we have never reported any difference.

I have also seen people using aluminium as a hard mask for DRIE ...

Regards,

Alex