4H-SiC Metal-Semiconductor-Metal Ultraviolet Photodetectors in Operation of 450 °C

This work demonstrates the high-temperature operation of metal-semiconductor-metal (MSM) photodetectors (PDs) up to 450 degrees C using lightly Al-doped epitaxial 4H-SiC thin films. The responsivity of the PDs under 325-nm illumination is 0.0305 A/W at 20-V bias at room temperature. The photocurrent-to-dark-current ratio of the SiC MSM PDs is as high as 1.3 x 10(5) at 25 degrees C and is 0.62 at 450 degrees C. The rise/fall time of the PDs is increased slightly from 594 mu s/684 mu s to 684 mu s/786 mu s as the temperature increases from room temperature to 400 degrees C. These results support the use of 4H-SiC PDs in extremely high temperature applications.