Utilization of SiC MOSFET Body Diode in Hard Switching Applications

Abstract

This work discusses the possibility of using SiC MOSFET body diode in switching power conversion applications, focusing on performance and reliability aspects.

Evaluation of reverse recovery characteristic of silicon carbide metal–oxide–semiconductor field‐effect transistor intrinsic diode

“…The forward voltage drop of the SiC SBD is much lower than that of the SiC MOSFET intrinsic diode. Therefore, using the SBD as the anti‐parallel diode of the MOSFET, almost all the current will flow through the SBD instead of the intrinsic diode, and the reverse recovery current of the intrinsic diode at high temperature can be reduced sufficiently [17].…”

“…The main parameters of the double pulse test bench are listed in Table 1. A current transformer (CT) or low inductance shunt resistor is usually used for device current measurement [17, 25]. In this setup, the shunt resistor has to be mounted on the DBC substrate, and may suffer very high temperature (200°C) during the test, which will lead to resistance shift and reduce the accuracy.…”

“…The bipolar degradation phenomenon of SiC devices is investigated in [14][15][16], which mainly occurs in high-voltage rating devices. A burn-in test shows that the 1.2 kV SiC MOSFET performs high robustness as well as very small voltage and on-resistance shift by using the intrinsic diode as the freewheeling diode [17,18].…”

Overview of 1.2kV – 2.2kV SiC MOSFETs targeted for industrial power conversion applications

“…Since SiC MOSFET's body diode has a much lower recovery charge than its Si counterpart, concerns about impact of body diode on the inverter losses is alleviated. Even if an antiparallel Schottky diode is used, it will have comparable switching losses to the body diode approach [10].…”

“…The recent advances at GE and elsewhere have cleared the path for widespread adoption of SiC devices in power conversion applications. Such achievements include: Schottky diode product introductions by Infineon and Cree [4,5] validated commercial feasibility of material; qualification testing of GE MOSFETs [6] in accordance with the most stringent automotive standard AEC-Q101 [7] has shown that the devices meet survivability and parametric stability requirements at operating temperature of 200 o C. Additionally, the risk of bipolar degradation of SiC MOSFET body diode was mitigated through material quality improvement [8,9] or by limiting device body diode SOA to high frequencies and short forward conduction durations [10]. It is, therefore, expected that MOSFET will become the SiC device of choice for high power industrial applications by offering superior performance and reliable, cost competitive system solutions.…”