Jarod, Many years ago, there was a program called "PROLITH" that modeled exposure and development simulations for positive novalac photoresists. Below is a reference to a paper that introduced it. A few years after it was introduced they tried to market it commercially, and I don't know the current status. You may be able to trace down the author, Chris Mack. Mack C. A. : ³PROLITH : a comprehensive optical lithography model² , SPIE, 538, pp. 207-219 (1985). Brad Cantos On 10/22/08 12:22 PM, "jarod vincent"wrote: > Dear all, > > Is there any software for etching/development simulation? I found there is > no such package in Ansys. Is there any commercial software? > Thank you for suggestion. > > Best Regards > Jarod Vincent