Bias temperature instability in SiC metal oxide semiconductor devices

Abstract

Although silicon carbide (SiC) metal oxide semiconductor field-effect transistors (MOSFETs) are commercially available, bias temperature instability (BTI) defined as shifts in V th in SiC MOSFET and V fb in MOS capacitor after the device is operated at a high temperature, seriously affects device reliability and limits further commercial applications. These instabilities are mainly attributed to charge trapping at and near the SiC/SiO2 interface and mobile ions in a gate oxide. The consequences of V th instability are serious and can worsen the performance and lifetime of SiC MOS devices. In this review, the SiC/SiO2 interface issue is introduced, and BTI occurring in current SiC MOS devices is described in detail. V th/V fb instability behavior induced by measurement and stress conditions, microscopic defects and instability mechanisms, recent measurement techniques of near-interfacial oxide traps, and BTI improvement resulting from the fabrication processes are described. BTI improvement mainly involves the control of charge trapping and movements of ions. The fabrication processes are related to oxidation and pre- and post-oxidation treatments. This review can help deepen our understanding of BTI and reduce its influence on SiC MOS devices performance.