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. Regard, Alton On 9/29/06, Isaac Chanwrote: > Alton, > > Are you talking about the ripples on the sidewall caused by standing wave > interference pattern, or the line edge roughness seen from the top due to > the resist's molecular roughing/photomask pattern roughness? > > Regards, > Isaac