SiO 2 insulating layers were first deposited onto GaN by photochemical vapor deposition ͑photo-CVD͒ technology using a deuterium (D 2 ) lamp as the excitation source. Physical, chemical, and electrical characteristics of the Al/SiO 2 /GaN metalinsulator-semiconductor ͑MIS͒ capacitors are reported for the first time. It was also found that the limiting factor of SiO 2 growth rate was the number of SiH 4 and O 2 molecules available to provide excited Si and O atoms. Furthermore, it was found from high-frequency capacitance-voltage measurements that the photo-CVD SiO 2 /n-GaN interface state density, D it , was estimated to be 8.4 ϫ 10 11 cm Ϫ2 eV Ϫ1 for the photo-CVD SiO 2 layers prepared at 300°C. With an applied field of 4 MV/cm, the oxide leakage current density was found to be only 6.6 ϫ 10 Ϫ7 A/cm 2 .

SiO 2 insulating layers were deposited onto 4H–SiC substrates by a photochemical vapor deposition (photo-CVD) technique. It was found that the SiO2 growth rate increases linearly with total SiH4/O2 density for a fixed ratio of SiH4 and O2 partial pressure, due to the increasing densities of SiH2 and excited O atoms. It was also found that the interface state density, Dit, is equal to 3.27×1012, 3.16×1012, and 5.66×1011 cm−2 eV−1 for photo-CVD SiO2 layers prepared at 150, 300, and 500 °C, respectively. Furthermore, it was found that the leakage current was only 4.15×10−8 A/cm2 with an applied field of 4 MV/cm for the 500 °C photo-CVD grown Al/SiO2/4H–SiC metal–insulator–semiconductor capacitor.

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In this study, off-state breakdown voltage (V BD) and hot-carrier-induced degradation in high-voltage n-type metal–oxide–semiconductor transistors with various BF2 implantation doses in the n− drift region are investigated. Results show that a higher BF2 implantation dose results in a higher V BD but leads to a greater hot-carrier-induced device degradation. Experimental data and technology computer-aided design simulations suggest that the higher V BD is due to the suppression of gate-induced drain current. On the other hand, the greater hot-carrier-induced device degradation can be explained by a lower net donor concentration and a different current-flow path, which is closer to the Si–SiO2 interface.

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