| Title |
Oxidation Process of GaN Schottky Diode for High-Voltage Applications |
| Authors |
하민우(Ha, Min-Woo) ; 한민구(Han, Min-Koo) ; 한철구(Hahn, Cheol-Koo) |
| DOI |
https://doi.org/10.5370/KIEE.2011.60.12.2265 |
| Keywords |
GaN ; AlGaN ; Schottky diode ; Power device ; Oxidation |
| Abstract |
1 kV high-voltage GaN Schottky diode is realized using GaN-on-Si template by oxidizing Ni-Schottky contact. The Auger electron spectroscopy (AES) analysis revealed the formation of NiO_x at the top of Schottky contact. The Schottky contact was changed to from Ni/Au to Ni/Ni-Au alloy/Au/NiO_x by oxidation. Ni diffusion into AlGaN improves the Schottky interface and the trap-assisted tunneling current. In addition, the reverse leakage current and the isolation-leakage current are efficiently suppressed by oxidation. The isolation-leakage current was reduced about 3 orders of magnitudes. The reverse leakage current was also decreased from 2.44 A/cm^2 to 8.90 mA/cm^2 under -100 V-biased condition. The formed group-III oxides (AlO_x and GaO_x) during the oxidation is thought to suppress the surface leakage current by passivating surface dangling bonds, N-vacancies and process damages. |