I need a good textbook on contact/proximity photolithography with a focus on both theory and partical equipment issues. I have quite a few lithography books, but they are focused on projection printing such as steppers. I have all three of Dave Elliot photolithography books, and Helbert's book and I proofread Levinson's book, but they only mention, if they mention at all, contact/proximity lithograph in passing. I am running resolution tests on my contact/proximity tools and getting interesting results and would like to understand them better. In particular across the wafer variation in resolution. If a book is not available, technical papers would be fine also. Edward H. Sebesta