Hi Bob:
Thanks for your help. I have tried Piranha etching at room temperature for
1hour, but it doesnot work. Do you have any idea how long it should be left
at 100C? Another thing is that I did not do the 100% oxygen plasma before
piranha etching. Thanks.

Regards,
Yilei Zhang

-----Original Message-----
From: bobhendu@aol.com [mailto:bobhendu@aol.com]
Subject: Re: [mems-talk] residues on RIE etched sio2

Yilei:

You can first use 100% oxygen plasma to remove polymer then follow with
H2SO4+H2O2 wet bath at 100 degrees C rinse with di water then place in HF
solution for removal of SIO2 remaining mask. Bob Henderson