IEEE Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia 2018)

231 / 2017-11-22 10:10:30

Ultralow Angle Bevel-Etched Junction Termination Extension for High Voltage SiC Power Devices

SiC GTO,power devices,JTE,Bevel,Ultralow Angle

Plenary track > Device characterization and modeling

The ultralow angle (ULA) bevel-etched (BE) junction termination extension (JTE) for high voltage SiC power devices is proposed and investigated in this paper. The local bevel alleviates the electric field (E-field) crowding at each step corner and thus allows an increased breakdown voltage (BV) and a wide process tolerance. With a small bevel angle of 2°, the 1-step ULA-BE JTE reaches over 90% of the ideal BV of parallel plane junction and exhibits the BV 3kV higher than that of conventional (Con.) vertically-etched (VE) JTE. The 3-step ULA-BE JTE delivers 2.7X improvement in the etching depth window compared with Con. VE JTE. We have performed the experiment of 1-step etch of the 4H-SiC ULA-BE JTE. The etching depth of 1.67um with the lateral distance of 50.2um is obtained, demonstrating the corresponding bevel angle of 1.9, which is a superior JTE solution for SiC high voltage power devices.