3.2 Practical Characterization

Characterizing and understanding a lithography process is an important part of using processes effectively in manufacturing. Unfortunately, the requisite characterization experiments are expensive and time-consuming. Simulation provides an ideal tool to enhance given experimental characterization and improve understanding of a given process. The ease and flexibility of modeling tools also allow for quick process changes leading to optimization studies. In many cases of such practical characterization applications the speed of the simulator is more important than its physical accuracy. If a model is, in spite of its simplicity, reasonably correct and particularly fast, it can be efficiently used to characterize the lithography process and understand the complex interaction among parameters. Three important examples for the practical use of simulation tools are presented in the subsequent sections.