Patent ID: 7042564
Filing Date: 2006-05-09
Classification: G01N,G06T

Abstract:
1. A method of inspecting a plurality of wafers in an optical inspection tool, the method comprising the steps of: generating a reference wafer; polishing said reference wafer in a chemical mechanical polishing process following a metal deposition process such that the reference wafer is representative of a fully polished wafer; scanning said polished reference wafer into an inspection tool prior to performing further processing on the reference wafer; generating a gray level map for said scanned reference wafer; performing a metal deposition process on a number of wafers; polishing said number of wafers after said metal deposition process in a chemical mechanical polishing process; scanning said polished number of wafers into an inspection tool prior to performing further processing on the wafers; generating a number of gray level maps for one or more of said scanned wafers; comparing said gray level map of said reference wafer with one or more gray level maps of said number of said scanned wafers, determining whether one or more wafers exhibits an acceptable polishing quality based on said comparison; and returning the wafer to a polishing process if said comparison step leads to a determination that said wafer is under-polished.