Simulation of Layer Thickness Measurements of Quantum Well Structures by In Situ Single‐Wavelength Ellipsometry

Simulations have been performed of the polarizer (P) and analyzer (A) readings that would result from in situ ellipsometric measurements at 632.8 nm of specific quantum well structures using a faraday-modulated null ellipsometer. It is shown that for a GaAs-AlGaAs quantum well structure involving layers that differ by 2% in the real part of their index of refraction at 632.8 nm the variation in P and A is small, i.e., 1.5 o in P and 1 o in A. However, it is shown that the Faraday-modulated null ellipsometer with an accuracy of better than 0.01 o in P and A can make meaningful measurements on such quantum well structures