TRITERTIARYBUTYLALUMINUM AS AN ORGANOMETALLIC SOURCE FOR EPITAXIAL-GROWTH OF ALGASB

A new organometallic source, tritertiarybutylaluminum (TTBAl), has been used in growth of AlxGa1-xSb epilayers by low pressure organometallic vapor phase epitaxy. Ternary alloys were grown over the whole composition range 0<x less than or equal to 1 on GaSb and GaAs substrates from TTBAl, triethylgallium, and triethylantimony (TESb) or trimethylantimony (TMSb). All layers exhibited mirror surface morphologies. Photoluminescence was observed for layers with, x<0.2, the composition that corresponds to the indirect transition. The background of C and O in AlSb grown with TESb was similar to 2X10(18) and similar to 6X10(19) cm(-3), respectively, and similar to 1.5X10(19) and similar to 1.5X10(19) cm(-3), respectively, for AlSb grown with TMSb. All layers exhibited p-type conductivity with hole concentration increasing with x, and saturating similar to 5X10(18) cm(-3) for x=1 which is about 10 times lower compared to layers grown with conventional Al sources. (C) 1995 American Institute of Physics.