THE EFFECT OF GAAS SURFACE STABILIZATION ON THE PROPERTIES OF ZNSE GROWN BY ORGANOMETALLIC VAPOR-PHASE EPITAXY

Organometallic vapor phase epitaxial growth of ZnSe on GaAs was carried out using dimethylzinc (DMZn) and dimethylselenide (DMSe) as the reactants. Unlike III-V systems, where growth is always started by first introducing column V precursor, the growth of ZnSe can be initiated either by introducing DMZn first (Zn-stabilization) or DMSe first (Se-stabilization). A systematic study of the properties of ZnSe epilayers, grown under these two surface stabilization conditions, was carried out using photoluminescence (PL) and double crystal X-ray diffraction (DCD). Layers grown on Se-stabilized substrates exhibited superior photoluminescence spectrum, but had higher X-ray full width at half maximum (FWHM) compared to those grown on Zn-stabilized surfaces. Detailed studies revealed that layers grown on Se-stabilized surfaces were tilted with respect to the substrate. A possible cause for the differences in the ZnSe layers grown on these two surfaces is proposed.