Dear Jie

I found that what is microloading effect in dry etching.
Thank you for your help.

Regards,

Jungwook Choi

-----Original Message-----
From: mems-talk-bounces@memsnet.org [mailto:mems-talk-bounces@memsnet.org]
On Behalf Of Jie Zou
Sent: Saturday, January 17, 2009 12:09 PM
To: General MEMS discussion
Subject: Re: [mems-talk] Distortion of silicon beam after DRIE process

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