Hi Jim,

I saw your post on MEMS-talk (below).  Do you have any references on
your use of Crystalbond 509 with DRIE (STS?) through-etch processes?  I
am trying to use Crystalbond 509 in the STS DRIE at our fabrication
facility and need to convince the local process engineer that it is safe
to do so.  Any information you can provide would be great.  Thank you.

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My guess is that your bond is not good, especially in the center of the
wafer because the resist "glue" can't ever dry in the center.

We have had success using backing wafers which have a shallow (50 um
deep) pattern of radial spokes and annular rings (looks like a dart
board  pattern) etched into the surface. The spokes extend to the edge
of the wafer and are a few mm wide. We oxidize these wafers so they
don't get etched after punchthrough. We bond the wafer to be etched to
the backing wafer by spinning the backing wafer with 1-2 um resist
(Shipley 510LA) at 2000 rpm. The wafers are gently pressed together and
baked on a hotplate for 30 minutes at 110 C. The channels provide a
path for the gas which evolves during resist drying to escape. After
etching, the channels provide a path for acetone to enter, speeding up
the release.

We have also had success with Aremco Crystalbond 509 (clear) wax which
dissolves in acetone.

Jim

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Max Perez



Graduate Student

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Microsystems Laboratory

4200 Engineering Gateway RM 2110

Mechanical and Aerospace Engineering

University of California, Irvine   92697

http://oxide.eng.uci.edu/lab/general.htm

949.824.6314

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