Dear colleagues,

I am trying to isotropically etch glass wafers. I want to etch the mask
directly, but after etch in 1:1 BOE/HF, I found that the Cr was lift off
and etched away, and the lateral etch rate is much higher than vertical.
I don't understand why is that, maybe because the etching of Cr, but accord-
ing to CRC hand book, Cr should be able to stand for HF. Is there anyone did
the similar process? How can I get good isotropic etching of glass wafer?
Any suggestions and explanations are highly appreciated. Thanks a lot.

Ingrid Y. Xu
Microfabrication and Application Lab
The University of Illinois at Chicago
TEL: (312)-413-7576