P A P E R    T I T L E
Model Development for Image Reversal Resist Lithography

A U T H O R  /  C R E D I T S
Charles Feng, Ben Keppeler, Jerry Wang, and Alice Fischer-Colbrie
Microwave Technology Division, Hewlett-Packard Company
Santa Rosa, California

A B S T R A C T
The variation due to batch-to-batch inconsistency and aging can be a major process control issue for image reversal resist. We experimentally found that the dose-to-activate and the develop-to-clear time can be used to characterize both the batch-to-batch variation and resist aging. Using simplifying assumptions, we have developed a new mathematical model that correlates both resist linewidth and undercut with basic resist characteristics and processing conditions. This model greatly simplifies the resist qualification process and saves engineering time.