Semiconductor thin-film optical constant determination and thin-film thickness measurement equipment correlation

摘要

There are several methods for correlating thin film thickness measurement equipment. The most commonly used method is to program in an offset that gets systematically added to or subtracted from the thickness calculation. Measurement errors can occur using this 'fudge factor' method because the relationship between the reference thicknesses and the measured thicknesses is not, in general, a fixed constant or simple function. A better method for correlating thin film thickness measurement equipment is to tune the instruments to the process by refining the internal optical constants.