INSB, GASB, AND GAINSB GROWN USING TRISDIMETHYLAMINOANTIMONY

GaInSb alloys as well as the constituent binaries InSb and GaSb have b een grown by organometallic vapor phase epitaxy using the new antimony precursor trisdimethylaminoantimony (TDMASb) combined with convention al group III precursors trimethylindium (TMIn) and trimethylgallium (T MGa). InSb layers were grown at temperatures between 275 and 425 degre es C. The low values of V/III ratio required to obtain good morphologi es at the lowest temperatures indicate that the pyrolysis temperature is low for TDMASb. In fact, at the lowest temperatures, the InSb growt h efficiency is higher than for other antimony precursors, indicating the TDMASb pyrolysis products assist with TMIn pyrolysis. A similar, b ut less pronounced trend is observed for GaSb growth at temperatures o f less than 500 degrees C. No excess carbon contamination is observed for either the InSb or GaSb layers. Ga1-xInxSb layers with excellent m orphologies with values of x between 0 and 0.5 were grown on GaSb subs trates without the use of graded layers. The growth temperature was 52 5 degrees C and the values of V/III ratio, optimized for each value of x, ranged between 1.25 and 1.38. Strong photoluminescence (PL) was ob served for values of x of less than 0.3, with values of halfwidth rang ing from 13 to 16 meV, somewhat smaller than previous reports for laye rs grown using conventional precursors without the use of graded layer s at the interface. The PL intensity was observed to decrease signific antly for higher values of x. The PL peak energies were found to track the band gap energy; thus, the luminescence is due to band edge proce sses. The layers were all p-type with carrier concentrations of approx imately 10(17) cm(-3). Transmission electron diffraction studies indic ate that the Ga0.5In0.5Sb layers are ordered. Two variants of the Cu-P t structure are observed with nearly the same diffracted intensities. This is the first report of ordering in GaInSb alloys.