Influence of Gas Annealing on Sensitivity of AlN/4H-SiC-Based Temperature Sensors

In this study, the physical and electrical characteristics of an AlN/4H-SiC Schottky barrier diode-based temperature sensor annealed in various gas atmospheres were investigated. An aluminum nitride (AlN) thin film was deposited on a 4H-SiC substrate via radio-frequency sputtering followed by annealing in N(2) or O(2) gas. The chemical composition of the film was determined by X-ray photoelectron spectroscopy (XPS) before and after annealing, and its electrical properties were evaluated by plotting a current–voltage (I–V) curve. The voltage–temperature (V–T) characteristics of the sensor were extracted from the current–voltage–temperature (I–V–T) plots constructed in the temperature range between 475 and 300 K in steps of 25 K. Sensitivities of 9.77, 9.37, and 2.16 mV/K were obtained for the as-grown, N(2)-annealed, and O(2)-annealed samples, respectively.