Characteristics of Oxygen Implanted Indium Phosphide

Oxygen implantation was performed on n-type (undoped and Sn doped) andp-type (Zn doped) InP. Ion implantation was done at ion energy of 50 and 100 keV with implantation doses of 10¹⁰, 10¹¹, and 10¹²/cm², Carrier compensation was observed in p-InP and some n-InP samples as confirmed by current-voltage (I-V) and capacitance-voltage (C-V) measurements. Deep level transient spectroscopy was used to characterize defect levels and their relation to carrier compensation. The compensation comes from free carrier trapping in damage induced defect levels. In p-InP, the dominant trap levels were located deep in the band gap with activation energy of 0.57-0.61 eV below the conduction band. This may be the reason that p-InP can be made highly resistive. For n-InP, observed damage induced trap levels located in the upper half of the band gap, with activation energies of 0.28 or 0.35 to 0.47 eV below the conduction band, caused the difficulty in making n-InP highly resistive. Carrier creation was observed in n-InP which may come from certain shallow donor type defect levels.