A Novel Self-Activated Gate-Clamping SiC MOSFET Enhancing Short Circuit Capability With Merit of Multicell Combination

This work proposes a novel self-activated gate-clamping (SAGC) silicon carbide (SiC) MOSFET to enhance the short circuit (SC) capability. The clamp MOSFET, integrated in the power MOSFET, is normally off. The clamp MOSFET is mainly activated by the high temperature of around 1220 K under SC conditions, well below its thermal runaway temperature of 1620 K. This can form a low-resistance path between the power gate (PG) and source. The SAGC MOSFET can increase the SC withstand time from several μs to an almost limitless value, as verified at different bus voltages of 400, 600, and 800 V, respectively. Furthermore, the proposed SAGC MOSFET has the advantage of being combined with the multicell MOSFET. This combination overcomes the extra area introduced by the clamp MOSFET, thereby reducing the equivalent cell pitch. The combined MOSFET is verified at 400-V bus voltage. It activates at 10 μs, suppressing thermal runaway and significantly improving the SC withstand time. The proposed novel SAGC MOSFET successfully realizes the same SAGC function and exhibits a uniform circuit density distribution, demonstrating an excellent intrinsic device self-protection capability.