APPARATUS AND METHOD FOR MEASURING THICKNESS PROFILE AND REFRACTIVE INDEX DISTRIBUTION OF MULTI-LAYERED THIN FILM USING TWO-DIMENSIONAL REFLECTOMETRY

摘要

PURPOSE: An apparatus and a method are provided to achieve improved reliability and accuracy of measurement, while reducing the measurement time by measuring the thickness profile and refractive index distribution at multiple points within a predetermined area. CONSTITUTION: An apparatus comprises a sample substrate transfer unit for supporting a sample substrate; an optical unit for providing light to be projected on the sample substrate; a narrow band pass optical filter set for selectively filtering the light projected on the sample substrate or the light reflected from the sample substrate; charge-coupled devices arranged in a two-dimensional way, and which sense the reflected light incident through optical filters(538) mounted on the narrow band pass optical filter set; a frame grabber for grabbing picture frame data contained in the reflected light sensed by charge-coupled devices; a computing element for computing the film thickness, thickness profile or refractive index by iteratively performing a non-linear error minimization method, through the use of data grabbed by the frame grabber; an image processor(548), an information processor(550) and a controller for processing picture frame data and controlling the computing element.