Technology and properties of GaAlAsSb layers grown on GaSb substrates

Abstract

LPE growth of Ga1-xAlxAsySb1-y on (100) GaSb substrates has been investigated for wide range of aluminum content in the melt, xAl1=0.01 - 0.06, various growth temperatures, and various amount of supersaturation. Epilayers were characterized by means of XRD, TEM, EPXMA, and SIMS. It has been found that LPE growth at Tapproximately equals 5300C produces good quality Ga1-xAlxAsySb1-y layers with Al content in the solid up to x equals0.24 and latice mismatch (delta) a/a not exceeding 5*10-4. As for the growth of higher aluminum content alloys at higher temperatures Tequals590 - 6000C, good results have been obtained unless the Al content in the melt does not exceed xAl1equals0.02 giving perfectly matched Ga1- xAlxAsySb1-y epilayers with Al content in the solid by up to x equals0.3. By introducing an interlayer, either of the lattice matched Ga0.91In0.09As0.08Sb0.92 or Ga0.70Al0.30As0.03Sb0.97, LPE growth from the melt with Al content up to xAl1equals0.06 becomes possible and enables fabrication of Ga1-xAlxAsySb1-y layers with Al content in the solid as high as xequals0.62. Ga1-xAlxAsySb1-y layers obtained from the melt with xAl1equals0.04 were characterized by lattice mismatch (Delta) a/aequals(8-9)-10-4, an increase of (Delta) a/a to 2.2*10-3 was observed for epilayers obtained from the melt with xAl1equals0.06.