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), compared to the peaks of the junction barrier Schottky diode and the Schottky barrier diode (2.1 mV K and 1.9 mV K, 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.