NUMERICAL-ANALYSIS OF NORMAL REFLECTANCE DATA AS APPLIED TO THE STUDY OF OXIDE-FILMS ON COPPER

A numerical study of spectroreflectometric data is presented together with a discussion of the underlying physical assumptions. A special technique is employed for the quantitative analysis of spectral reflectivity curves measured at normal incidence and of their development over the course of time during film growth. Given a minimal set of eight appropriately chosen data points, the simultaneous derivation of film thicknesses and optical constants is possible. The method is successfully applied to a copper substrate-oxide system. In addition, the dispersion curves for the refractive index and the extinction coefficient in the visible range are determined using a fast and simple algorithm. The calculations are based on experimental quantities which can be measured for the oxide film actually under investigation. Calibration is necessary with respect to literature values for the optical constants of solid copper which exhibit some scatter. This is the main source of error. The corresponding uncertainties of our results are carefully analysed. © 1979.