Vertical GaN-Based Temperature Sensor by Using TiN Anode Schottky Barrier Diode

Vertical GaN Schottky barrier diode was fabricated as temperature sensor by using a thermally stable TiN anode. The current-voltage characteristics of the diode measured at various temperature present a zero-temperature coefficient (ZTC) bias point of approximately 0.6 V. At the voltage below the ZTC bias point (sub-threshold region), the forward voltage at a fixed current decreases linearly with the increasing temperature, resulting in a sensitivity of approximately 1.3 mV/K. In the reversely biased region, the leakage current also presents temperature-dependent behavior with a sensitivity of approximately 19.7 mA/K regardless of the bias. Those results can be interpreted by the thermionic emission model.