Hi, so the stress was so strong that it overcome the adhesion force between
the BOX and the Device layer? It sounds very strange to me. You mean it
peeled off the BOX or it slided on the BOX? Both look impossible. And the
DRIE usually comes with a cryogenic back cooling, thus I don't think it
brings too much heating issues.
how wide is your beams? I have some 2~3 um legs (after 1um undercutting from
one side) and device layer 5um thick, but never saw the distortion
happened.

Just one thought. Did you mean the beams were not straight? Microloading
would cause faster etching rate in the region with larger intervals between
objects than the crowd region. So the beam could look like distorted to the
less crowd region.

Jie

On Wed, Jan 14, 2009 at 9:05 PM, Jungwook Choi  wrote:

> 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

*  Zou Jie (Jay)
*  Department of Physics
*  University of Florida
*  Tel: +1-352-846-8018
*  Email: zoujiepku@gmail.com
*  Homepage: http://plaza.ufl.edu/zoujie/