METHOD FOR EVALUATING METAL CONTAMINATION IN SEMICONDUCTOR SAMPLE AND METHOD FOR MANUFACTURING SEMICONDUCTOR SUBSTRATE

摘要

One aspect of the present invention relates to a method for evaluating metal contamination in a semiconductor sample by using a DLTS method. The method comprises: obtaining a first DLTS spectrum by measuring a DLTS signal while changing temperature, the DLTS signal being generated in such a way that a reverse voltage (VR) for forming a depletion layer at a semiconductor junction on a semiconductor sample and a weak voltage (V1) for trapping carriers in the depletion layer are alternately and periodically applied; obtaining a second DLTS spectrum by measuring a DLTS signal generated by periodically applying the reverse voltage (VR) to the semiconductor junction while changing temperature; and obtaining, using the second DLTS spectrum or a spectrum obtained by approximating the second DLTS spectrum by a straight line or a curve as a correction spectrum, a differential spectrum between the correction spectrum and the first DLTS spectrum. The differential spectrum is used as an evaluation DLTS spectrum.