MONITORING CHANGES IN PHOTOMASK DEFECTIVITY

摘要

A reticle that is within specifications is inspected to generate baseline candidate defects and their location and size. After using the reticle in photolithography, the reticle is inspected to generate current candidate defects and their location and size. An inspection report of filtered candidate defects and their images is generated so that these candidate defects include a first subset of the current candidate defects and their images and exclude a second subset of the current candidate defects and their images. Each of the first subset of candidate defects has a location and size that fails to match any baseline candidate defect's location and size, and each of the excluded second subset of candidate defects has a location and size that matches a baseline candidate defect's location and size.

主权项

1. A method of inspecting a photolithographic reticle, the method comprising:
performing a first inspection of a reticle that has been identified as being within specifications so as to generate a plurality of baseline candidate defects and their location and size; after using the reticle in one or more photolithography processes after the first inspection, performing via a reticle inspection tool a second inspection of the reticle so as to generate a plurality of current candidate defects and their location and size values; and generating an inspection report of a plurality of filtered candidate defects and their images, wherein the filtered candidate defects include a first subset of the current candidate defects and their corresponding plurality of candidate defect images and exclude a second subset of the current candidate defects and their corresponding plurality of excluded images, wherein each of the first subset of current candidate defects included in the inspection report has a location and size value that fails to match any baseline candidate defect's location and size value by a predefined amount, and each of the second subset of current candidate defects excluded from the inspection report has a location and size value that matches any baseline candidate defect's location and size value by the predefined amount.