Hi Robert,

Maybe you can try this:

Dilute the photoresist with butanone into a very diluted solution;
Fill a petri dish with the PR "solution";
Put your wafer in the dish, and use ultrasonic bath if you think it's
helpful to get rid of the trapped air.
Leave the wafer in the dish for several hours, and let the solution dry out
itself.

I have never tried this method, but I know someone use it for other purpose.

Good luck,

2008/10/27 Black, Robert 

>     I'm trying to fill some deep vias (25um wide, 70um deep) with resist. I
> can't seem to get the resist to go any deeper than about 40um. The best
> results were with using a PGMA pre-wet.  I've tried some 55cp resist that I
> coated three times to fill (based on top down zygo) and some 120 cp resist.
> X-sections show both resists to only be 40um down the vias.
>    Any suggestions?
>
> Robert

--
Best regards,
Yours sincerely
Fei Wang
______________
Postdoctoral researcher, Dr
MIC - Department of Micro and Nanotechnology
Technical University of Denmark (DTU)
Building 344, 1st floor, Room no. 130
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Denmark
Tel:  +45 4525 6311
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Email: fei.wang@nanotech.dtu.dk
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