Methods for Studying the Electrical Characteristics of the Epitaxial Layers of n/p-InxGa1 – xAs Solid Solutions for Large-Area Device Structures

A search for an optimum technique for studying the electrical characteristics of thin n/p-InxGa_1–xAs semiconductor layers with different doping levels has been carried out. The primary task has been to measure the main electrical characteristics by different methods using resistivity (conductivity), majority carrier concentration, dependence of the main electrical parameters on the doping type and level, and their comparison. Using the example of the p- and n-In_0.01Ga_0.99As solid solutions grown by MOCVD, a technique for studying the main electrical characteristics of the epitaxial layers has been proposed, which takes into account the estimated homogeneity on large-area samples. Results obtained by different methods, including photoluminescence, contactless surface resistivity measurement, van der Pauw (Hall effect), electrochemical capacitance–voltage profiling, and in situ control, have been compared. Basing on the results obtained and comparison with the literature data, conclusions have been drawn concerning the need, sufficiency, and complementarity of the methods for controlling and studying semiconductor epitaxial structures.