LOW-PRESSURE METALORGANIC VAPOR-PHASE EPITAXY AND CHARACTERIZATION OF(AL,GA)SB GASB HETEROSTRUCTURES/

Ternary AlxGa1-xSb layers and AlSb/GaSb multi-quantum-well structures were grown by low pressure metalorganic vapor phase epitaxy (LP-MOVPE) . First, a comparative investigation on the GaSb and AlSb growth kinet ics with the standard methyl and ethyl group-III precursors (TMGa, TMA 1, TEGa, TEAI) was performed to establish which starting materials sho uld be preferentially utilized. Our studies revealed that only the com bination of the ethyl precursors TEGa, TEA1 and TESb exhibit a well ma tched reactivity for the LP-MOVPE deposition of (AI,Ga)Sb/GaSb heteros tructures. Ternary AlxGa1-xSb layers (0 < x < 1) grown on GaSb substra tes showed low temperature photoluminescence responses for Al contents smaller than the direct-indirect crossover concentration. Furthermore , GaSb/AlSb multi-quantum-well stacks with good structural and optical quality were deposited which could be verified by X-ray diffraction, Raman and photoluminescence measurements.