DEEP LEVELS IN UNDOPED BULK INP AFTER RAPID THERMAL ANNEALING

Deep levels in rapid thermal annealed InP in metal-insulator-semiconductor (MIS) structures have been studied using deep level transient spectroscopy. Two different insulating layers used in forming MIS structures, a silicon nitride layer and an oxide layer, were fabricated by plasma enhanced chemical vapor deposition and concentrated nitric acid, respectively. In the samples annealed at temperatures between 700 and 900 °C for 10 s, two deep levels having apparent energy depths of 0.43 and 0.35 eV below the conduction band were newly generated. Then, it is considered that they are the defects related with phosphorus vacancy and its complex. Other deep levels observed between 0.55 and 0.79 eV below the conduction band were related with insulating layers. We show an evidence that they might be interface states in the junction of InP and insulator.