Cdid: A system for identifying the root cause of a defect in semiconductor wafer fabrication

This paper proposes a system called CDID for diagnosing semiconductor fabrication process. CDID can identify the carry-over defect type that contributed to a defective cluster captured by an in-line inspection tool during a specific fabrication processing step. Let R_x be a defective cluster captured by an in-line inspection tool during the fabrication processing step ps_i. First, CDID would identify the defect type of R_x by comparing the image of R_x with the images in reference wafer maps of previous defect clusters captured at ps_i. Let d_j be the identified defect type. CDID would use rules of inferences for identifying the root cause of d_j CDID would utilize d_j as a trigger for the appropriate defect specification rules using the standard rules of inferences. Based on established and well-known causes of defects, CDID composes rule-based defect specifications in the form of propositional logic's premises. The premises are triggered by applying the inference rules. By applying the defect specification rules recursively using the inference rules, CDID can identify the root cause of d_j The quality of CDID has been experimentally evaluated by measuring its prediction accuracy. Results revealed marked prediction accuracy.