Torsten Gerlach, IMMM, Tel. wrote:
>
> Dear MEMS colleagues,
> we are trying to fabricate thick photoresist (30-50um) structures on
> silicon substrates.
>
> We are using the resist AR-P 322, lambda 308-450, and developer AR
> 300-26 from the company Allresist in Berlin, Germany. The exposing is
> carried out with an Electronic Vision mask aligner.
>
> The obtained aspect ratio is rather poor. The angle included by the
> side-walls and the substrate surface is around 60 deg. No difference
> was observed using chromium or photo emulsion masks.
>
> Any suggestions on how to approach the ideal case of vertical side-
> walls are apreciated.
>
> Torsten Gerlach
>
> =========================================
> Technical University of Ilmenau
> Dept. of Micro System Technology
> P.O. Box 0565
> D-98684 Ilmenau
> F.R. Germany
> phone: +49 / 3677 / 69-1295,   fax: -1296
> =========================================
>
>