Yuanfang Gao,

Hopefully I won't sound too much like a broken record (er, skipped CD? -
I guess we are in the 21st century now) to the rest of the board, but
the best method I know of to ensure coverage over the edges of such a
slope is via spray coating.

Here is the information link again:

http://www.micromagazine.com/archive/04/03/brubaker.html


Best Regards,
Chad Brubaker


-----Original Message-----
From: Yuanfang Gao
Sent: Tuesday, February 14, 2006 4:13 PM
To: [email protected]
Subject: [mems-talk] problem of patterning metal electrodes
intomicrochannels

Dear all,


I met a problem while I tried to pattern metal electrodes into
microchannels
of 15-20 um deep, the width is in the range of 10-70 um.


I used S1813 positive resist for lift-off, the problem is that at the
edge
of the channel, I found out a metal line along one side of the channel,
i.e.
the photoresist is not covering the edge of the channel, another problem
is
that the wire to the channel is easily broken.


I used KOH etching of silicon to create the channels, the profile is not
vertical, has the 54.74 degree slope.


Anyone can help me to solve these two problems?  Thanks a lot!