DAMAGE ASSESSMENT OF A WAFER USING OPTICAL METROLOGY

摘要

A method of assessing damage of a dual damascene structure includes obtaining a wafer after the wafer has been processed using a dual damascene process. A first damage-assessment procedure is performed on the wafer using an optical metrology process to gather damage-assessment data for a first set of measurements sites on the wafer. For each measurement site in the first set of measurement sites, the optical metrology process determines an amount of damage of a damaged area of a periodic grating in the measurement site. The damage- assessment data includes the amount of damage determined by the optical metrology process. A first damage-assessment map is created for the dual damascene process. The first damage-assessment includes the damage- assessment data and the locations of the first set of measurement sites on the wafer. One or more values in the damage-assessment map are compared to damage- assessment limits established for the dual damascene process to identify the wafer as a damaged or undamaged wafer.