To MEMS folks,

Here is the problem I am looking into and haven't had much luck with it:
there is an array of narrow trenches etched on silicon wafers, each
trench(cavity) is 1um wide, 100um long, and 10 um deep. The pitch is about
100um. Now I want to spin a layer of polymer on top of the wafer and seal
the trenches, but not to fill them. Actually I would like as little polymer
as possible to go into the trenches (so the polymer should have high
viscosity and molecular weight). The thickness of the polymer layer is not
critical, but the surface should be reasonably smooth for additional work. I
have been told that some polyimide may do the work but not sure yet. Any
suggestions or leads regarding materials, sources and processes would be
greatly appreciated! Thanks for your help.

Regards,

H. Zhang
[email protected]