PICOSECOND PHOTOCONDUCTIVITY STUDIES OF LIGHT-ION-BOMBARDED INP

An investigation of the dependence of the photoconductive lifetime and dark resistivity on ion mass, bombarding dose, and substrate temperature is presented for ion-implanted Fe-doped InP. Be and He ion bombardments as low doses cause a decrease in the dark resistivity of the semi-insulating InP and introduce defects which act as efficient carrier recombination sites without impairing the free-carrier mobility; above a threshold dose a second phase of damage is evidenced by a sharp decrease in carrier mobility and dark resistivity. Proton-induced damage is shown to result in an anomalous decrease in the dark resistivity of the Fe-doped InP, while being less effective at introducing carrier recombination sites.