Identifying Wafer Fabrication Defect Signatures

摘要

We introduce a system called IDS for diagnosing semiconductor fabrication process. IDS can identify the carryover defect that contributed to a defective cluster captured by an in-line inspection tool during a specific fabrication processing step. Let Rx be a defective cluster captured by an in-line inspection tool during the fabrication processing step psu First, IDS would identify the defect type of Rx by comparing the image of Rx with the images in reference wafer maps of previous defect clusters captured at psu Let dj be the identified defect type. IDS would use rules of inferences for identifying the root cause of dj. It will utilize dj as a trigger for the appropriate defect specification rules using the standard rules of inferences. By applying the defect specification rules recursively using the inference rules, IDS can identify the root cause of dj. We experimentally evaluated the quality of IDS. Results revealed marked prediction accuracy.