Study on enhancing of the surge current capabilities of embedded SBDs in SWITCH-MOSs and body-PiN-diodes in SiC trench MOSFETs

Abstract

This study investigates the surge current capabilities of embedded Schottky barrier diodes (SBDs) in SiC SBD-integrated trench metal–oxide–semiconductor field effect transistors (MOSFETs) (SWITCH-MOSs) using titanium and nickel for the Schottky metals. The results demonstrated that a 25% enhanced surge current capability can be achieved for an embedded SBD with a higher barrier height of nickel compared to those with titanium and that it was comparable to body-PiN-diodes in a standard SiC trench MOSFET (IE-UMOSFETs). Furthermore, the study demonstrated the superior surge current capabilities of body-PiN-diodes in IE-UMOSFETs that have wide and thick Cu heat capacitance blocks attached to chip surfaces, and a significant improvement of 57% in surge current capability was achieved with 2.9 × 4.1 mm2 wide and 0.4 mm thick Cu blocks. Notably, there was no sacrifice of I–V characteristics in the third quadrant and reverse recovery characteristics or the resistance in the first quadrant with the Cu blocks.