The parts are <100>, not <110>.  The etch solution is 60% nitric, 10%
acetic, 5% hydrofluoric, rest water.  The temperature is 75-80 degrees C.
The stains are visually detected with an eye loop or naked eye (we don't
need to go to further magnification for our purposes).  The stains are
whitish, likely silicon oxide.  We've run some SEM studies, revealing
nothing but silicon and oxygen.

George

-----Original Message-----
From:   [email protected] [mailto:[email protected]] On
Behalf Of [email protected]
Sent:   Wednesday, January 02, 2002 9:05 PM
To:     [email protected]
Subject:        [mems-talk] Re:etch Si(110) and Si(100) in KOH

If you got poor results in etching (110) you either had too much water in
your etch or your wafer was of axis by several degrees.  What is your etch
solution composed of and at what temperature are you etching at?  An off
axis
wafer, which are sliced on purpose that way for diffusion control, will show
what looks like a stair case of many steps.  If the cause was too much water
then you get pits and bumps and even lines.  Let us know which problem you
had and the solution is at hand.

Campman
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