Temperature-dependent operating margins of proton-irradiated integrated 4H-SiC CMOS current mirrors

Integrated 4H-SiC CMOS current mirrors and co-fabricated MOSFETs were characterized at temperatures up to 180 °C and after 15 MeV proton irradiation. The SiC mirrors retain highly linear current transfer over the measured current ranges, with coefficients of determination of 0.99943–0.999996 across the reported conditions. Heating reduces the threshold-voltage magnitude of both NMOS and PMOS devices, whereas irradiation predominantly increases the PMOS threshold-voltage magnitude and the supply voltage required for stable mirroring. Using a common target current ratio of 2.47, the minimum measured supply voltage of the type 2 mirror increases from 7.5 V before irradiation to 10.5 V after a fluence of 5 × 10¹³ cm⁻² at room temperature, and decreases to 9.5 V when the irradiated circuit is measured at 180 °C. Devices annealed in hydrogen before irradiation require higher supply voltages: 12.0 V at room temperature and 10.5 V at 180 °C. These results demonstrate partial, temperature-dependent improvement of the circuit operating margin after irradiation. They do not establish thermal removal of radiation-induced defects. The device and circuit measurements identify threshold-voltage shifts and processing history as relevant considerations for the operating margins of this SiC CMOS platform.