Processing issues and modeling

A brief perspective is given initially on the goals, exposure methods, performance and challenges in the lithography process. The basic framework for simulating optical lithog- raphy is then presented using three important physical aspects: imaging, resist exposure- bleaching and resist development etching. Image quality in both contact/proximity and projection printing are considered. The verification by comparison of simulated resist pro- files with SEM cross sections from resist images on wafers in then considered. The chap- ter concludes with a discussion of the challenges facing projection printing and the technology directions emerging to meet them. Greater detail on many of the concepts and models introduced in this Chapter can be found in subsequent chapters.