Thermal Effect Study for a Chemically Amplified Resist

다국어 초록 (Multilingual Abstract)

For sub-100 nm pattern generation, thermal treatment is one of the new process extension techniques
with current day lithography equipment and chemically amplified resists. The key element to
introduce these new techniques is an understanding of the mechanistic behaviors that drive photo resist
image rendering. Thermal processes, such as softbake, post-exposure bake, and thermal reflow,
are essentially the same, but produce different chemical and physical behaviors in the chemically
amplified resist. In this paper, those thermal processes are described and modeled to investigate
the property changes of a positive-type 193-nm chemically amplified resist. The simulated results
agree well with experimental results. The thermal effects move the boundaries of the resist bulk to
a center point and make these boundaries dense. Due to pattern types, the thermal reflow process
technology and the overbake and underbake technologies of softbake and post-exposure bake can be
used for the 45-nm critical dimension. By combining the benefits of thermal processes, it becomes
possible to produce patterns below 45-nm critical dimension.