MBE GROWTH OF ZNCDSE AND MGZNCDSE ALLOYS ON INP SUBSTRATES WITH A GAINAS BUFFER-LAYER

Molecular beam epitaxy growth of ZnCdSe and MgZnCdSe systems on (001) InP substrates were investigated. These films were grown on a lattice- matched GaInAs buffer-layer which was ex-situ grown on (001) InP by me talorganic vapor phase epitaxy. During the thermal cleaning process pr ior to II-VI film growth, group-V molecular beams were not used. By in troducing this buffer-layer and lowering the initial growth temperatur e, the surface morphology of ZnCdSe films changed from rough to specul ar and the full width at half maximum (FWHM) of the double-crystal (00 4) X-ray rocking curves of the films decreased from more than 400 arcs econds to 60 arcseconds. The ZnCdSe film showed a very sharp excitonic emission in the 5 K photoluminescence spectra with a FWHM as narrow a s 5.5 meV. No emission through deep levels was observed. High-quality MgZnCdSe films were also obtained using a GaInAs buffer-layer.