Suppression of Punch-Through Current in 3 kV 4H-SiC Reverse-Blocking MOSFET by Using Highly Doped Drift Layer

Abstract

Low on-resistance 4H-SiC reverse-blocking (RB) metal-oxide-semiconductor field-effect transistors (MOSFETs) have been developed by adopting a non-punch-through (NPT) drift layer in order to suppress the punch-through (PT) current under the reverse-blocking condition. The n-type NPT drift layer was 40-μm thick doped to 3.7 × 1015 cm-3. The forward and reverse breakdown voltages of the fabricated NPT RB MOSFET were 3.6 kV and -3.0 kV, respectively. The differential specific on-resistance was 13.5 mΩ·cm2 at room temperature, which was 33% lower than that of a 3 kV PT RB MOSFET, demonstrating superiority of the developed NPT RB MOSFET as a high-performance bidirectional switch.

Keywords

• Silicon carbide (SiC)
• reverse-blocking capability
• non-punch-through (NPT) design
• Schottky contact
• metal-oxide-semiconductor field-effect transistor (MOSFET)