I am not trying to planarize the substrate. I want a coat ~ 0.2-0.5
microns of the polymer on the posts of the substrate. Of course, there
would stuff on the recesses, but that's not a concern.

Sandip Agarwal
Senior Scientist

Nano-Terra Inc.
790 Memorial Drive, Suite 202
Cambridge MA 02139
0 617 621 8500 x2302   C 713 471 0916   F 617 621 8501
[email protected]    www.nanoterra.com

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Matthew Walker
Sent: Wednesday, October 24, 2007 5:49 PM
To: General MEMS discussion
Subject: Re: [mems-talk] Striations during spin-coating

Sandip Agarwal wrote:
> I am trying to spin-coat a polymer (1% PMMA-butadiene copolymer in
> toluene) on a substrate that has topographical features that are 50x50
> micron posts and 10 microns tall. I observe striations or ripples that
> run from the center of the substrate to the periphery after
> spin-coating. Any solutions? I have tried varying the concentration
and
> dynamic dispensing without any success.
>