Methodology for Improving Temperature Sensing Performance and Thermal Stability of 4H-SiC JBS Diodes

In harsh industrial conditions, real-time and precise temperature monitoring is vital for system safety and efficiency, necessitating high-precision, durable, and reliable temperature sensors. However, developing sensors that balance high sensitivity with thermal reliability is challenging. Herein, high-sensitivity and high-linearity devices for high-temperature applications are successfully achieved by designing and fabricating 4H-SiC Junction Barrier Schottky (JBS) diodes. Notably, after 36 h aging at 500 °C, diodes with small active areas achieve a maximum sensitivity (S) of 1.65 mV °C^-1, with only a 6.8% reduction relative to the pristine device, while maintaining high linearity (R² > 0.999) over a broad current range (500 µA-2 mA). Specially, large active area diodes achieve the highest S of 2.24 mV °C^-1 among the reported Schottky-based devices. In addition, a critical aspect is the in-depth investigation of degradation mechanisms governing the performance degradation after high-temperature aging over 200-500 °C. The findings identify the presence of a 12 nm-thick interfacial layer and the significant increase in the interface state density between the titanium layer and 4H-SiC following aging at 500 °C. These results provide valuable methodologies for improving temperature sensing performance and thermal stability of 4H-SiC JBS Diodes.