Method and apparatus for measuring variations in composition in binary and ternary semiconductors utilizing electrolyte electroreflectance

摘要

There is disclosed an apparatus and method for measuring the variations in composition across the surface of binary and ternary alloy semiconductors utilizing electrolyte electroreflectance. The technique is non-destructive, can readily be employed under atmospheric conditions at room temperature, and is sensitive enough to determine changes of composition of about 1% with a spatial resolution of about 100&mgr;. The procedure is very useful for the selection of crystals for detector arrays, solid states lasers, or electronic devices. It can also be utilized as a convenient tool for evaluating material grown either in bulk form or epitaxial layers, thus providing feedback for the adjustment of crystal growth parameters. The apparatus includes a mechanism for stepping the semiconductor being investigated in two dimensions while performing electroreflectance measurements; the measurement results can then be plotted on contour maps.