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

-----Original Message-----
From: yilei zhang 
Subject: [mems-talk] residues on RIE etched sio2

Hello colleagues:
I used rie (10% O2, 90% CF4) to etch silicon with a polymer layer and a sio2
mask, but found the left sio2 cannot be further etched away with HF. I
searched the archive and found the RIE may generate a polymer layer or
fluorocarbon, and a layer of fluorinated si. I want to know is there any way
to remove the left sio2 mask? Thanks.

Regards,
Yilei Zhang