Baobao,

Sf6 only, or with Ar etches Si isotropically of nature. It will be more
or less impossible using this chemistry. You might want to try CF4 + O2
or a mixture of these and CHF3. There should be plenty of resources out
there to help you find something that works for you.

Regards,

Jobert van Eisden
SUNY Albany

-----Original Message-----
From: baobao
Subject: [mems-talk] Any good recipe for Si etch in ICP?

I am trying to do some Si etch. I use SF6 and Ar.
I hope to get straight side wall that is around 1
micro deep. But when I cleave and look it using SEM,
there are some undercut and the side looks like wet
etch.

i am not sure if anyone can give me some idea about
the recipe that i could use.