Beschreibung:
Effects of in situ etching of InP surfaces with PCl3 followed by low-temperature in situ chemical vapor deposition of phosphorus-nitride in a phosphorus-rich ambiance using NH3/PCl3/H2 on trap states of the interfaces were studied. The breakdown field of the phosphorus-nitride films was as high as 1×107 V cm−1 and the films showed trap-assisted conduction in high electric field with resistivity higher than 1×1014 Ω cm near the electric field of 1×107 V cm−1. Interface properties were found to be critically dependent upon PCl3 molar fraction, both the etching and deposition time, and the etching and deposition temperature. The frequency dispersion of capacitance-voltage characteristics in accumulation was about 3.3% for the frequency range from 10 kHz to 1 MHz. The hysteresis was as low as 0.17 V for the field electrode voltage swept between −6 and +6 V. The density of interface trap states, Nss, was 2×1011 cm−2 eV−1 at about 0.3 eV below the conduction-band edge of InP and was 8×1011 cm−2 eV−1 near the bulk Fermi level.