Alton,

Yes, post-exposure bake, if done properly, should be able to completely
remove those ripples on the sidewall. Typically, the thinner the resist
you use, the more vertical the profile can be. I have not used AZ9260
personally, but I don't see any problem to get it vertical. If you are
using contact lithography, the gap between resist and photomask mainly
affect your profile. If you have hard bake step after development, your
hard bake temperature above 110C will start to reflow your resist and
change its profile.

Regards,

Isaac Chan, Ph.D.


On Mon, 2 Oct 2006, Hsiu-Jen Wang wrote:

> Isaac,
>
>     Yes, the ripples on the sidewall actually made roughness. I used
> AZ 9260, and tried post expose bake but haven't taken SEM, so I'm not
> sure how it goes. By the way, I also would like to know sidewall of AZ
> 9260 in 4.7um thickness still be vertical? Or what photoresist should
> I use for this thickness. Vertical and smooth sidewall are the most
> important issues in my experiment. Thanks.