Identification and Sources of Impurities in InGaAs Grown by Liquid Phase Epitaxy

Abstract

ABSTRACTHigh purity In.53 Ga.47 As and InP with carrier concentrations [ND–NA] < 5×1015 cm−3 has been grown by the LPE technique on both n-type and semi-insulating substrates to detect and identify trace donor and acceptor impurities. Acceptor impurities have been detected in low temperature photoluminescence spectra where LPE melt baking and growth programs indicate a melt origin for two of these species, one of which is zinc. Data from semiconductor profiles provides evidence for sulfur and tin donor impurities, which comes from the rinse melt used to etch back substrates doped with the respective contaminants. Silicon and sulfur contaminants have been detected by SIMS measurements; and may arise not only from the indium and III-V materials, but also the graphite boat used to grow the epilayers. Volatile sulfur-containing compounds have been detected during high temperature bake-out of high purity graphite boats.