SURFACE AND INTERFACE ANALYSIS OF GASB GAAS SEMICONDUCTOR-MATERIALS/

This paper presents a detailed study on the surface and interface of M OMS-grown GaSb on GaAs using XPS, AES and SIMS techniques. It is found by XPS that at the surface and near surface regions antimony exists i n the forms of Sb2O5 and GaSb, and correspondingly gallium exists in t he forms of GaSb, Ga2O3 and elemental Ga, AES analysis shows that the epilayer (GaSb) growth time has very limited influence on the width of interdiffusion region, and that the width of the interdiffusion regio n of GaSb/GaAs grown at different temperatures is 340 +/- 30 Angstrom, which is much smaller than that of InSb/GaAs grown by the same method . The reasons are believed to be related to the lattice mismatch and t he dissociation energies for Ga-Sb and In-Sb bonds. More sensitive SIM S analysis reveals that there is a small amount of arsenic present at the GaSb epilayer, which increases with increasing temperature. Finall y two different kinds of SIMS techniques are compared, one using Ar+ a s ion source and collecting only the ion of the element of interest, t he other using Cs+ as ion source and collecting the combination of the element of interest with the Cs+ ion from primary beam. The latter is found to be more suitable for III-V semiconductor heterostructure ana lysis as a result of much improvement in overcoming the matrix effects .