Metal is generally not advised for DRIE since very often the metal
gets sputtered off and creates micro masks in your open area
resulting in grass.  My only suggestion would be to try a different
photoresist or  shorten your hard bake of your AZ9260.

What aspect ratios are you looking for and what is your minimum feature size?

Nik
Electrical Engineering
Penn State University

At 5:24 PM -0400 8/31/06, Xiaoguang \"Leo\" Liu wrote:
>Dear all
>I'm trying to do a  through wafer etch (550um) using silicon Deep RIE.
>I've tried with the AZ9260 photoresist. However, the reflow of the
>photoresist after hard bake makes the etching profile non-uniform.
>
>Does anybody know if metal can be used in the DRIE process. I've heard
>that people have done 2mm etching using Ni as a mask. However, our
>staff here says metal is not allowed in the chamber. It would be great
>if anybody could give some references on that. Thanks a lot