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 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</sup> cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> . 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·cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 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.