Study of GaAs Epitaxial Layer Using the Separated Medium Acoustoelectric Effect.

摘要

Electrical properties of GaAs epitaxial layer are studied by measuring the transverse surface acoustoelectric voltage, the attenuation of the surface wave when the semiconductor surface is depleted, and the time constant governing the return to the steady state condition of the delay line output after the semiconductor surface is accumulated. The spectral response of the attenuation and time constant is studied using a monochromator. The experimental results determine the uniformity and quality of the semiconductor epitaxial layer, the energy band, the distribution of surface states in the energy gap and the lifetime of surface states. A theory is developed for the acoustoelectric voltage when two carriers are present for better understanding of the experimental results when band-to-band transition is taking place. This method is simple, very sensitive, accurate, and needs no contact to the semiconductor surface. (Author)