Hi
I don't know about SiGe but I know the hot concentrated KOH will etch it the
same way it etches
High n-type or p-type farley good.
Shay
-----Original Message-----
From: [email protected] [mailto:[email protected]]
On Behalf Of D. Zhou
Sent: Wednesday, March 22, 2006 7:10 PM
To: MEMS_BBS
Subject: [mems-talk] Can KOH etch heavily-doped n-Si or SiGe?

Dear all,

Does anyone know whether or not KOH can etch heavily-doped n-Si or SiGe
(say, ~1X10^19/cm^3)?? I did a KOH etch test and found that the etch rate
for the heavily-doped n-SiGe can be ignored. The KOH mixture I used is
H2O:IPA:KOH=400g:100g:125g. Can KOH solution with a different concentration
etch the heavily-doped n-Si or SiGe? From the literature I have learned that
heavily-doped p-Silicon can be used as KOH stop layer, but I am not very
sure what happens to the highly-doped n-silicon.