Alloy Fluctuation in Mixed Compound Semiconductors as Studied by Deep Level Transient Spectroscopy

Deep level transient spectroscopy (DLTS) has been utilized to detect alloy fluctuation around defects in several kinds of alloy semiconductors. An increased half-width in the DLTS spectrum has been observed in the ternary and quaternary systems of InGaP and InGaAsP whereas the binary systems of GaP and InP have not shown such broadening. The broadening can be interpreted as a fluctuation of defect properties due to the increased freedom of atom arrangements around the relevant defect in the alloy systems.