AlGaAs epitaxial growth on (111)B substrates by metalorganic vapor-phase epitaxy

AlGaAs epitaxial layers were grown on (111)B-oriented GaAs substrates by metalorganic vapor-phase epitaxy (MOVPE). Mirrorlike surfaces can be obtained with a growth temperature of 875-900°C and a V/III ratio of 10-20, while a high density of hillocks appears with lower temperatures and/or larger V/III ratios. Hillock density is reduced by introducing misorientation on (111)B substrates. In this case, however, macrosteps appear on the surface when the misorientation angle is larger than 0.2°. Low-temperature photoluminescence indicates that single quantum wells can be formed on (111)B substrates by using MOVPE.