An efficient photoresist development simulator based on cellular automata with experimental verification

Abstract

An efficient and practical photoresist development simulator based on cellular automata is presented. Image reversal and chemical amplification processes are also simulated using this simulator. To verify the simulator, a series of experiments have been designed and performed using the Shipley SNR-248 negative resist, a stepper, and a deep ultraviolet source at 248 nm. Experiments were performed for periodic and isolated lines with pitches 300, 400, 500, and 1000 nm, for exposure energy doses of 11, 13, 17, and 23 mJ/cm/sup 2/, and with developer temperatures of 0, 20, and 80/spl deg/C. In all cases, the simulator results were found to be in very good agreement with the corresponding experimental results. The simulator has also successfully reproduced the incomplete opening effect observed in the case of close-spaced parallel lines.