Electrical characterization of GaAs single crystal in direct support of M555 flight experiment

An exploration of several nondestructive methods of electrical characterization of semiconductor single crystals was carried out. Two methods of obtaining the microwave skin depth, one for mapping flat surfaces and the other for analyzing the whole surface of small single crystal wafers, were developed to the stage of working laboratory procedures. The preliminary 35 GHz data characterizing the two types of space related single crystal surfaces, flat slices of gallium arsenide and small wafers of germanium selenide, are discussed. A third method of nondestructive mapping of donor impurity density in semiconductor surfaces by scanning with a light beam was developed for GaAs; its testing indicates reasonable precision at reasonable scan rates for GaAs surfaces at room temperature.