Large-area vertical Schottky barrier diodes based on 4H-SiC epilayers: Temperature-dependent electrical characteristics

Abstract

As an alternative to conventional silicon-based devices, 4H-phase silicon carbide (4H-SiC) is emerging as a promising semiconductor for particle detectors worked at high temperatures. In this work, 4H-SiC Schottky diodes with a vertical geometry and a sensitive area of 7 × 7 mm2 were fabricated. The electrical characterization parameters of devices were calculated from 300 to 473 K using I-V and Cheung’s function H(J)–J, in order to reveal the temperature-dependent performances. The results indicate that the ideality factor (n), barrier height (Φb), and leakage current are positively related to temperature. On the contrary, the on-resistance (Ron), series resistance (Rs), and built-in potential voltage (Vbi) are negatively dependent on temperature. In addition, these diodes with large areas exhibit a quite low leakage current and quite large rectification ratio simultaneously, demonstrating the high quality of these devices. Finally, the response characteristics of a Ni/4H-SiC detector were investigated under the irradiation of a 241Am alpha source. This work may provide a further understanding of the SiC-based detectors with large sizes for radiation detection applications at high temperature.