Photo-carrier and Electronic Studies of Silicon-Doped GaAs Grown by MBE Using PCR

Abstract

Photo-carrier radiometry (PCR) has been used to study the distribution of impurities and the lattice damage in silicon-doped gallium arsenide in a noncontact way. The results from the PCR study are correlated with Hall effect measurements. Samples for this study were grown by molecular beam epitaxy. Of all possible parameters that can be manipulated, the silicon effusion cell temperature was the only one that was varied, in order to obtain samples with different silicon concentrations. The distribution of impurities was obtained by scanning the surface of each sample. The PCR amplitude and phase images were obtained as a function of the x-y position. According to the PCR images, it is evident that the impurities are not uniformly distributed across the sample. From these images, the average value of the amplitude and phase data across the surface was obtained for each sample in order to study the PCR signal behavior as a function of the silicon effusion cell temperature.