Defects in Si-doped InxAl1-xAs (0<x<0.4) epilayers on GaAs substrates were systematically investigated by deep-level transient spectroscopy. Three electron traps, ranging from 0.22 to 0.89 eV, were observed in the MBE-grown InxAl1-xAs. Low-temperature growth as well as thermal annealing were found to be capable of reducing these defects effectively, especially the dislocation defect.
