High-temperature and reliability performance of 4H-SiC Schottky-barrier photodiodes for UV detection

With its wide bandgap, excellent electrical properties, and relative mature crystal growth technique, 4H-SiC is an attractive candidate material for fabricating high performance ultraviolet photodetectors, which have potential to work in harsh environments. In this work, a vertical type 4H-SiC Schottky-barrier photodiode is designed and fabricated. The photodiode exhibits very low dark current and high quantum efficiency in the entire temperature range from 25 to 200 °C. A high Schottky barrier height of over 1.58 eV and an ideality factor as low as 1.074 at room temperature are deduced for the semitransparent Ni/4H-SiC Schottky metal contact. The high-temperature reliability characteristics are evaluated by high-temperature storage at 200 °C and high-temperature spike annealing up to 550 °C.