Dear Jie

Thank you for your attention.

We performed 2nd DRIE right after 1st DRIE on same wafer, since we noticed
that the silicon layer on BOX was not fully etched.

The distortion of the beam was observed after 2nd DRIE process, not after
releasing.

We will contact to the vendor of our wafer according to your suggestion.

Regards,

Jungwook Choi


-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Jie Zou
Sent: Wednesday, January 14, 2009 1:37 PM
To: General MEMS discussion
Subject: Re: [mems-talk] Distortion of silicon beam after DRIE process

It could due to the residue stress of your SOI wafers. You might need to ask
the vendor first to rule out this possibility.

Was ur 2nd DRIE done after you performed one time of DRIE on that wafer or
you started with another new patterned wafer? And did you notice the
distortion after releasing (I mean etching away the Buried OX) or right
after DRIE?

Jie