Hello JinKee
First, Cr is easily oxidized when it is exposed to air which means it loses
most of functionality of Cr as an adhesion layer. Thus you want to avoid or
minimize the exposure of Cr to air after sputtering process.

Second, you might want to change PR coating recipe such as thickness, baking
temperature etc. It might help to improve adhesion force between PR and Cr
and the resistance of PR against glass etchant.

Third, you might try Au/Cr system rather than PR/Cr system as a mask for
glass etching. Au/Cr system has a higher resistance against glass etchant.

Fourth, you might also try p-Si as a mask rather than PR/Cr system. --> of
course, this is the best system for glass etching if you have available
facilities.

Good luck

Sung
-----Original Message-----
From: Jinkee Lee [mailto:Jinkee_lee@brown.edu]
Sent: Thursday, August 05, 2004 11:56 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] Soda lime glass channel etching

Hello,



When I am doing glass etching, I coated chromium sacrificial layer to
increase adhesion by sputtering, first. And on this layer, coat photoresist
1818, develop PR and etch Cr. Then after glass is exposed, start to etching
glass.



But, when glass is etching, the edge of sacrificial layer is defected.
Therefore, the side well of channel is very rough, not smooth.

If someone knows the answer how to increase adhesion between glass and Cr,
and Cr and photoresist, please let me know.

Thank you.



Jinkee Lee

Brown Univeristy, Division of Engineering

Ph.D. student@Microfluidics Lab, Tripathi Group.

  http://microfluidics.engin.brown.edu


182 Hope St. Providence RI 02912

Phone: (O) 401-863-3977, (C) 401-339-2771