The optimised design and characterization of 1200 V / 2.0 mΩ cm<sup>2</sup> 4H-SiC V-groove trench MOSFETs

Abstract

V-groove trench MOSFETs with the 4H-SiC{0-33-8} face as the trench sidewall for the channel region have been investigated. The on-resistance and breakdown voltage strongly depend on the aperture ratio of the buried p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> regions. The VMOSFETs with the buried p <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> regions of 71% on a 6-inch wafer exhibited a low specific on-resistance of 2.0 mΩ cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> with 1200 V blocking voltage. The threshold voltage is 2.3 V at 175°C, which shows the VMOSFETs have tolerability for an erroneous ignition under high temperature. The switching capability showed low switching losses over DMOSFETs on 4° off 4H-SiC(0001) face and normal operation under fast switching repetitive test (40 Vns <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> ). The stability of the threshold voltage was demonstrated by HTGB tests.