Determination of the depth distribution of carriers in silicon molecular beam epitaxially grown material by electrochemical capacitance-voltage measurements

Abstract

Abstract The technique of electrochemical capacitance-voltage profiling (eCV) is an interesting alternative to more conventional methods for obtaining a quick and accurate evaluation of the concentration and depth distribution of carriers in doped layers. This technique is particularly suited for thick epilayers since it offers the advantage of unlimited profileable depth. The eCV technique has been used for assessing the carrier distribution in various doped silicon layers grown by molecular beam epitaxy (MBE). Optimized measurement conditions (choice of electrolyte, etching and measuring potentials, etc.) were determined for both p-type and n-type doping and the technique is now being used on a routine basis. The carrier distribution of arbitrary doping profiles in p- and n-type silicon epilayers, and doping superlattices, have been obtained using eCV and the results were found in good agreement with secondary ion mass spectrometric measurements.