Characterisation of commercial SiC MOSFETs at deep-cryogenic temperatures

Abstract: Silicon carbide is a wide-bandgap semiconductor with an emerging CMOS technology platform and it is widely deployed in high power and harsh environment electronics. This material is also attracting interest for quantum technologies through its crystal defects, which can act as spin-based qubits or single-photon sources. In this work, we assess the cryogenic performance of commercial power MOSFETs to evaluate their suitability for CMOS-compatible quantum electronics. We perform a statistical study of threshold voltage and subthreshold swing from 300 K down to 650 mK, focusing on reproducibility and variability. Our results show significant performance degradation at low temperatures, including large gate hysteresis, threshold voltage shifts, and subthreshold swing deterioration. These effects suggest instability in electrostatic control, likely due to carrier freeze-out and high interface trap density, which may pose challenges for the reliable use of this transistor technology towards the realisation of quantum devices or cryo-CMOS electronics.