A 4H-SiC CTAT Temperature Sensor Operating Between 14 and 481 K

A 4H-Silicon Carbide (4H-SiC) complementary to absolute temperature sensor is characterized and analyzed in the operating temperature range between 14 K and 481 K and is based on 4H-SiC diode-connected lateral NMOSFET. It is an integrated circuit compatible with 4H-SiC CMOS technology. The sensor characteristic has a unique linear curve from 481 K down to 150 K, for saturation, or to 100 K, for subthreshold bias regime. In both cases, the linearity is high, with a coefficient of determination, R-2>0.99, and the sensitivity varies from - 1.98 to - 7.7 mV/K. The analysis shows that the limitation of the single transistor T-sensor, due to the oxide/semiconductor interface traps, is overcome by applying two different bias currents, whereas at very low temperatures, the loss of linearity is due to the increase of the effective channel mobility (saturation) or to the increase of the slope of the single transcharacteristics (subthreshold).