Vertical power Schottky barrier diodes using a high-k insulator

Several types of vertical power Schottky barrier diodes (SBDs) using a high-k (Hk) insulator, which have a low specific on-resistance (R_on) close to that of the superjunction (SJ) SBD with the same breakdown voltage (BV), are studied. By introducing an N⁺-poly-region in the Hk insulator at the anode side, the reverse leakage current of the Hk-SBD can be largely reduced without increasing the forward voltage drop. Simulation results based on Sentaurus show that, by using the N⁺-poly-region, the reverse leakage current of the 400 V Hk-SBD can be lowered by more than 40 times with R_on (=3.13 mΩ · cm²) equaling about eight times smaller than that of the conventional SBD having almost the same BV. It is also found that the reverse recovery behavior of the Hk-SBDs is much softer than that of the SJ-SBD. (paper)