Determination of compositional profiles and thicknesses of the etched surface of CdTe and Cd0.9Zn0.1Te by spectroscopic ellipsometry

In the etched surfaces of the leading semiconductor technological materials for room-temperature Gamma-ray and X-ray detection dielectric constants are functions of the chemical constituents that continuously vary in depth. It is shown that it is possible to determine their depth profiles directly from the ellipsometric measurements by constructing an appropriate algorithm for data interpretation. The function that is the depth profile of the chemical constituent and the corresponding ellipsometric ratio of reflection coefficients we related by the way of an operator equation. Using an effective medium approximation without knowledge of the actual function in depth and some ideas of the inverse scattering theory we demonstrate the effectiveness of the Spectroscopic ellipsometry. It is an attractive alternative of methods used for surface characterization such as RBS, MEIS, XPS, SIMS and TEM.