Dear Colleagues,

I am trying to fabricate 3D structures in thick positive photo resist
(20-50 micron) by direct laser writing with a blue laser (440nm).
Does anybody have experience, which type of resist is best suitable for
this purpose?
At the moment I am using Microposit S1828. It has good properties for
thin films, but exceeding 10 micron, the softbake procedure seems to be
too critical.
The very surface layer is almost development-inhibiting, which results
in a very inhomogenous development for shallow structures.
Unfortunately, most thick film resist are optimized for high contrast
and aspect ratios, which is disadvantegous if you want to obtain
arbitrary depths.

Thank you and with best regards, Thomas Ammer.


Thomas Ammer
CSEM  Micro-Optics
Badener Str. 569
8048 Zurich
Switzerland
Tel: +41 1497 1434
[email protected]