Normally-Off Trench-Gated AlGaN/GaN Current Aperture Vertical Electron Transistor with Double Superjunction

Abstract

This study proposes an AlGaN/GaN current aperture vertical electron transistor (CAVET) featuring a double superjunction (SJ) to enhance breakdown voltage (BV) and investigates its electrical characteristics via technology computer-aided design (TCAD) Silvaco Atlas simulation. An additional p-pillar was formed beneath the gate current blocking layer to create a lateral depletion region that provided a high off-state breakdown voltage. To address the tradeoff between the drain current and off-state breakdown voltage, the key design parameters were carefully optimized. The proposed device exhibited a higher off-state breakdown voltage (2933 V) than the device with a single SJ (2786 V), although the specific on-resistance of the proposed method (1.29 mΩ·cm−2) was slightly higher than that of the single SJ device (1.17 mΩ·cm−2). In addition, the reverse transfer capacitance was improved by 15.6% in the proposed device.

Keywords

• superjunction
• current aperture vertical electron transistor (CAVET)
• vertical HEMTs
• breakdown voltage (BV)
• reverse transfer capacitance (C_rss)