Influence of As/Al and Sb/Al gas flow ratios on growth of AlAs₁-_xSb_xalloys

AlAsi₁-_xsb_xepilayers were grown on InP (100) substrates using the metalorganic chemical vapor epitaxial growth technique. Experimental results demonstrate that the solid concentration of AlAsSb is more naturally expressed as a function of the input As/Al partial pressure ratio, and not of the V/III ratio or the Sb mole fraction in group V used during the growth. In fact, the AlAs solid concentration and the input partial pressure ratio of As to A1 are proportional to each other. According to the phase diagram described above, the controllability of the solid concentration of AlAsSb could be improved.