Control and signal processing for photoresist processing in microlithography

The lithography process is a critical step in the fabrication of nanostructures for integrated circuit manufacturing. In this paper, a summary is presented of several projects applying control and signal processing techniques to lithography. We begin with a presentation of a nonoptical lithography process under development in our lab. The proposed lithography technique is based on chemically altering the surface in a spatially selective manner to achieve a patterned substrate. In addition to the exposure step, photoresist processing is also critical in lithography. Based on current limitations of photoresist thermal processing system, a new integrated system is designed to improve the performance of temperature sensitive chemically amplified photoresists used in deep-UV lithography. Two case studies where control and signal processing techniques have made an impact in photoresist processing are also presented.