3.4 kV Breakdown Voltage Ga 2 O 3 Trench Schottky Diode with Optimized Trench Corner Radius

Abstract

To improve the blocking performance of Ga 2 O 3 Schottky barrier diode (SBD), based on the field strength distribution at the bottom of the trench and edge effect, the impacts of structure parameter on breakdown voltage and the figure of merit (FOM) were investigated by TCAD simulation and optimization. The results indicated that the breakdown voltage raised as the corner radius of trench R and the trench length K increased in a certain range, in which K was employed to optimize the structure with a minor mesa width W. In addition, Al 2 O 3 was confirmed as an appropriate dielectric layer material in Ga 2 O 3 SBD. When the structure parameters were W = 1 μ m, R = 0.6 μ m, K = 0.8 μ m–0.9 μ m and Al 2 O 3 was selected as dielectric layer materials, a Ga 2 O 3 trench SBD with breakdown voltage of 3.4 kV and the FOM of over 1.7 GW·cm −2 was proposed.