Comparison of Temperature Sensing Performance of 4H-SiC Schottky Barrier Diodes, Junction Barrier Schottky Diodes, and PiN Diodes

We present a comparison between the thermal sensing behaviors of 4H-SiC Schottky barrier diodes, junction barrier Schottky diodes, and PiN diodes in a temperature range from 293 K to 573 K. The thermal sensitivity of the devices was calculated from the slope of the forward voltage versus temperature plot. At a forward current of 10 μA, the PiN diode presented the highest sensitivity peak (4.11 mV K−1), compared to the peaks of the junction barrier Schottky diode and the Schottky barrier diode (2.1 mV K−1 and 1.9 mV K−1, respectively). The minimum temperature errors of the PiN and junction barrier Schottky diodes were 0.365 K and 0.565 K, respectively, for a forward current of 80 μA±10 μA. The corresponding value for the Schottky barrier diode was 0.985 K for a forward current of 150 μA±10 μA. In contrast to Schottky diodes, the PiN diode presents a lower increase in saturation current with temperature. Therefore, the nonlinear contribution of the saturation current with respect to the forward current is negligible; this contributes to the higher sensitivity of the PiN diode, allowing for the design and fabrication of highly linear sensors that can operate in a wider temperature range than the other two diode types.