{'fraction_non_alphanumeric': 0.024045261669024046, 'fraction_numerical': 0.0014144271570014145, 'mean_word_length': 5.742857142857143, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
In-situ critical dimension control during post-exposure bake with spectroscopic ellipsometry

Strong correlation between de-protection induced thickness reduction and amplified chemical reaction in the exposed area of the chemically amplified resist (CAR) during post-exposure bake (PEB) has been established. The optical properties of the resist film due to the thickness reduction can be detected using a spectroscopic ellipsometer. In this paper, a rotating polarizer spectroscopic ellipsometer is developed and a proposed control scheme is presented for signature profiles matching. With the implementation of the control scheme, wafer-towafer critical dimensions (CD) uniformity is improved by 5 times.