Optical properties of photoresist films investigated by real-time spectroscopic ellipsometry

Abstract

We employed real-time spectroscopic ellipsometry (SE) to investigate the optical properties of photoresist (PR) films. The fast data acquisition capability of the real-time SE enabled us to monitor the evolution of the optical properties of PR during exposure. These real-time data were analyzed using the effective medium theory and regression process. Thus, we could obtain not only the optical functions of PR both before- and after-exposure but also the information on the kinetic behavior in between. This analysis process was compared with Dill's exposure model. Real-time SE was a useful technique for the end-point detection in the exposure process but fast data acquisition was needed to avoid error caused by probing source.