It is crucial to predict hard failure in photolithography process to determine design rules and process condition in the product development stage. Accurate prediction of hard failures through simulation have powerful effects such as shortening the product development period and improving mass production yield. Previously, parameters used to determine whether a pattern is expected to fail include NILS (Normalized Image Log-Slope), image contrast, or chemical distribution in the photoresist. However, these methods are almost infeasible because the accuracy becomes low as process condition changes and calibration process of chemical distribution is too complicated. In this paper, a novel method using optical parameters and machine learning is proposed to predict hard failures of ADI (After Development Inspection) patterns, and this methodology was evaluated in the process of applying inorganic photoresist.
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