Silicon carbide: A unique platform for metal-oxide-semiconductor physics

TLDR

Power electronics for a sustainable energy future demand higher efficiencies, and silicon carbide (4H‑SiC) offers superior power handling, higher operating temperatures, and greater conversion efficiency than silicon, yet SiC MOSFETs remain relatively new with performance limited by interface defects that have been studied for over a decade. This review aims to address the key scientific challenges of low channel mobility and bias‑temperature instability in SiC MOSFETs by surveying recent progress in interface engineering and device physics. The authors examine device‑physics and atomic‑scale mechanisms underlying mobility loss and bias‑temperature instability, and evaluate recent interface‑engineering advances that enhance channel transport.

Abstract

A sustainable energy future requires power electronics that can enable significantly higher efficiencies in the generation, distribution, and usage of electrical energy. Silicon carbide (4H-SiC) is one of the most technologically advanced wide bandgap semiconductor that can outperform conventional silicon in terms of power handling, maximum operating temperature, and power conversion efficiency in power modules. While SiC Schottky diode is a mature technology, SiC power Metal Oxide Semiconductor Field Effect Transistors are relatively novel and there is large room for performance improvement. Specifically, major initiatives are under way to improve the inversion channel mobility and gate oxide stability in order to further reduce the on-resistance and enhance the gate reliability. Both problems relate to the defects near the SiO2/SiC interface, which have been the focus of intensive studies for more than a decade. Here we review research on the SiC MOS physics and technology, including its brief history, the state-of-art, and the latest progress in this field. We focus on the two main scientific problems, namely, low channel mobility and bias temperature instability. The possible mechanisms behind these issues are discussed at the device physics level as well as the atomic scale, with the support of published physical analysis and theoretical studies results. Some of the most exciting recent progress in interface engineering for improving the channel mobility and fundamental understanding of channel transport is reviewed.