Review on the Reliability Mechanisms of SiC Power MOSFETs: A Comparison Between Planar-Gate and Trench-Gate Structures

Abstract

To clarify the current research situation and offer a better understanding of the reliability for silicon carbide (SiC) power metal-oxide-semiconductor field-effect transistors (MOSFETs), a comparison among the reliability mechanisms between planar-gate and trench-gate SiC power MOSFETs, which have not been comprehensively summarized, is made in this work. The latest studies focusing on the reliability issues of commercial SiC MOSFET products, including the planar-gate device, the double-trench device and the asymmetric trench-gate device, are reviewed. For the existing of the gate trenches and the unique structures protecting them, SiC trench-gate MOSFETs express quite different instability phenomena from the planar-gate ones under various ultimate and long-term electro-thermal stresses. The influences of these stresses closely related to the practical operation conditions on SiC power MOSFETs, including the avalanche stress, the short-circuit (SC) stress, the surge current stress of the body diode, and the switching stress, are discussed and reviewed in details.