Monitoring and control of photoresist properties and CD during photoresist processing

Abstract

Current approaches to control critical dimensions (CD) uniformity during lithography is primarily based on run-to- run (R2R) methods where the CD is measured at the end of the process and correction is done on the next wafer (or batch of wafers) by adjusting the parameter set-points. In this work, we proposed a method to monitor the various photoresist parameters (e.g. photoresist thickness, photoactive compound) and CD in-situ and in real-time. Through modeling and real-time identification, we develop new in-situ measurement techniques for the various parameters of interest in the lithography sequence using existing available data in the manufacturing process. © 2010 Copyright SPIE - The International Society for Optical Engineering.