Patent ID: 7821655

Claim:
A wafer processing system, comprising: a wafer processing chamber including a support for positioning at least one wafer within an interior region of the chamber, wherein the support comprises at least one temperature measuring device in thermal contact with the at least one wafer; a source that routes a wafer treatment material into the processing chamber for removing a coating from an exposed surface of the at least one wafer; an optical measuring apparatus including receiving optics in optical communication with the chamber, wherein the receiving optics are focused on or about a surface of the coating at a shallow angle and configured to detect an interference pattern associated with a wavelength spectrum, wherein the shallow angle is close to 90 degrees relative to the normal plane of the wafer such that radiation contributing to the interference pattern captured by the receiving optics has a localized origin; a single external broadband illumination source disposed above the wafer and adapted to project broadband radiation into the chamber, wherein the single external broadband illumination source is the only illumination source; and computing means in communication with the receiving optics for computing the film thickness, or the film removal rate, or the endpoint from the interference pattern or combinations thereof.