Justin,

We've had some success with SU-8 on glass. We found that complete cleaning
and dehydrating the glass before applying the SU-8 was very important for
good SU-8 adhesion. Furthermore, in some cases, we've used oxygen plasma to
get better adhesion.

Make sure you do a good post exposure bake (PEB--after UV exposure, before
developing) before you put your substrate in the developer (PGMA) or
nothing will survive. Glass takes awhile to warm up, so the PEB needs to be
longer than for silicon. I recommend you go really long on the PEB, then
back off until you get it just right.

In most cases, after the SU-8 had cured, we found that adhesion was good to
glass and silicon. In fact it's too good--it's very difficult to remove if
you want to recycle a wafer.

These days we don't like to use glass much; we found that reflections from
the bottom side of the glass ruins the quality of our patterning. Maybe you
will have better luck.

-Mark.


>In trying to get SU-8 to work as a photoresist on glass, I've had a hard
>time getting the SU-8 to stay on the glass once I start developing it in
>the SU-8 developer.
>Does anyone know if I an adhesion layer on the glass under the SU-8?  or
>is there still another solution?
>Also, is SU-8 supposed to bond with (and stick to) a silicon wafer when
>processing it as a photoresist, even after placing it in the SU-8
>developer?
>
>Any suggestions will help.
>Thanks in advance.
>
>Justin Holzer
>
>holzer@eng.utah.edu
>
>
>
>
>
>

--------------------------------------------
Mark Bachman, Ph.D.
mbachman@uci.edu / 949-824-6421 (-3732 fax)
Research Physicist, Microsystems Engineering
University of California at Irvine