Surface and interface phonon and plasmon excitations in iii-v semiconductor materials

Abstract

The long range nature of dipolar scattering in HREELS of III-V materials gives the technique the ability to probe into the solid over a variable length range up to about 1000Å. This allows us to investigate the layer profile of heterostructures via excitation of surface and interface phonon modes. In doped materials, beam energy dependence of the intensity of coupled plasmonphonon modes provides information about carrier distribution close to the surface. We present examples of the application of HREELS to GaAs/Ga 1-XAl XAs heterostructures and both n- and p-type GaAs(100). Procedures needed to avoid carrier depletion at the surface of the samples are described.