SYSTEMS AND TECHNIQUES FOR OPTICAL MEASUREMENT OF THIN FILMS

Methods provided herein may include illuminating a region on a wafer within a semiconductor processing tool, the wafer having a layer of a material that is at least semi-transparent to light and has a measurable extinction coefficient, and the region being a first fraction of the wafer's surface, detecting light reflected off the material and off a surface underneath the material using one or more detectors and generating optical data corresponding to the detected light, generating a metric associated with a property of the material on the wafer by applying the optical data to a transfer function that relates the optical data to the metric associated with the property of the material on the wafer, determining an adjustment to one or more processing parameters for a processing module, and performing or modifying a processing operation in the processing module according to the adjusted one or more processing parameters.