Hello all,
I also get grass formation during the etching of negative photoresists.
I have tried different chemistries of photopolymers, but this grass is
the same in all cases. The only material that I haven't seen grass is
with positive photoresist.
The RIE conditions I am using are 100 sccm O2, 100 mTorr, 80 W, 5-10
min.
Grass formation can be reduced/eliminated by adding CF4 or CHF3. In my
case, I don't want to use any fluorinated gas to avoid etching of
underneath layers.
Any suggestions on how to reduce this grass formation?
Thanks,
Marcia

-----Original Message-----
From: mems-talk-bounces@memsnet.org
[mailto:mems-talk-bounces@memsnet.org] On Behalf Of Masahiko Takei
Sent: Sunday, October 23, 2005 8:48 PM
To: General MEMS discussion
Subject: Re: [mems-talk] Grass during polyimide etch

Hello guys,

I have a similar problem of glass during ICP deep etching for Si.
In case I try to etch until 200-300 um depth with any etching mask of
PR, SiO2, and Al, it appears for sure.
If you guys have any good solution, pls let me know.