[mems-talk] fudging/spreading around the PR features

[K.P.Nichols at utwente.nl]

Sadhana,

The email from Ed made some very good suggestions for rigorously determining the problem. This might be something much easier to fix though, so I'd try these simple things first:

1) It's possible this is just a problem with your exposure, which could give something that looks like "fudging."  You could be exposing with too great a gap between your mask and your sample. If you know how to adjust this on the aligner you're using, try reducing it (if not, ask the technician in charge of it, and they'll know how to change the modes).

2) If that doesn't work, try just extending your development time. Take whatever you're doing now and double it, and see if it makes any difference (if you have a microscope with the right filters, check what you're doing as you develop). Make sure to adequately dry your wafer after developing too. If there's some water left over, it could make your features look like they've "fudged."

3) Make sure you're cleaning your substrate well enough before use. And, if it's just Si or glass, use a quick spin of HMDS.

- Kevin

*********************************
Kevin Paul Nichols
MESA+ Institute for Nanotechnology
Mesoscale Chemical Systems
Meander 151
University of Twente
Postbus 217
7500 AE Enschede
The Netherlands

Office: +31 (0)53 489 26 31
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Email : k.p.nichols at utwente.nl


-----Original Message-----
From: mems-talk-bounces at memsnet.org on behalf of Sadhana Patil
Sent: Fri 10/5/2007 7:44 PM
To: mems-talk at memsnet.org
Subject: [mems-talk] fudging/spreading around the PR features
 
I am new to Photolithography. I am doing Photolithography with S1813.
Many a times I get fudging/spreading of photoresist around the edge of
the photoresist features after developing. They look more or less like
threads spreading outward from the feature.
Does anyone know what am I doing wrong?