GAAS GROWTH BY PHOTON-ASSISTED METALORGANIC MOLECULAR-BEAM EPITAXY USING ETHYL DERIVATIVES OF GALLIUM AND ARSENIC

Epitaxial layers of GaAs have been successfully grown by metalorganic molecular beam epitaxy (MOMBE) and photon-assisted MOMBE using triethylgallium (GaEt(3)) and diethylarsine (AsEt(2)H) as gallium and arsenic sources, respectively. Good epitaxial layers with smooth surface morphologies were grown on GaAs(100) substrates under a typical total pressure of 1.3 x 10(-3) Pa and for As/Ga molar ratios greater than or equal to 5. Epitaxial growth takes place from the relatively high substrate temperature of 550 degrees C even using photon irradiation. The morphology and the growth rate did not change significantly with UV light and the growth rate is weakly dependent on the deposition temperature. However, low temperature photoluminescence spectra clearly exhibit a decrease of the carbon contamination for the samples grown with UV irradiation. On the whole, the film quality is slightly improved under UV irradiation but the magnitude of the effect is relatively modest, probably because of the limited energy density available from the used lamp.