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 ( <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s), a comparison among the reliability mechanisms between planar-gate (PG) and trench-gate (TG) SiC power <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s, which have not been comprehensively summarized, is made in this article. The latest studies focusing on the reliability issues of commercial SiC <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> products, including the PG device, the double-trench device and the asymmetric TG device, are reviewed. For the existing of the gate trenches and the unique structures protecting them, SiC TG <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s express quite different instability phenomena from the PG 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 <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small> s, including the avalanche stress, the short-circuitstress, the surge current stress of the body diode, and the switching stress, are discussed and reviewed in details.