V2O5/4H-SiC Schottky Diode Temperature Sensor: Experiments and Model

Performances of temperature sensors based on Divanadium Pentoxide/4H polytype of silicon carbide, V2O5/4H-SiC, and Schottky diodes are analyzed. The devices with an active area of 1.96 x 10⁻³ cm² were characterized in a temperature range between 147.22 and 396.75 K and in a current range between 1 μA and 1 mA. Measurements reveal that at a bias current of 16 μA, the diode forward voltage shows a linear dependence on the temperature, with a sensitivity of 1.86 mV/K and a temperature error of 0.64 K. Sensors have also shown a good repeatability of sensing over more cycles of measurements in the considered temperature range. Numerical simulations are performed, and device physical parameters are obtained from the best fit with experimental data. From simulation results, we show that the conduction mechanism of the sensor is affected by traps at the V2O5/4H-SiC interface, which have been modeled with an exponential tail. Moreover, device parameters, as epilayer doping concentration and thickness, have been varied in order to evaluate the variations on the sensor performances.