4H-SiC Schottky diode arrays for X-ray detection

摘要

Five SiC Schottky photodiodes for X-ray detection have been electrically characterized at room temperature. One representative diode was also electrically characterized over the temperature range 20℃ to 140 ℃. The performance at 30 ℃ of all five X-ray detectors, in both current mode and for photon counting X-ray spectroscopy was investigated. The diodes were fabricated in an array form such that they could be operated as either a 2×2 or 1×3 pixel array. Although the devices showed double barrier heights, high ideality factors and higher than expected leakage current at room temperature (12 nA/cm~2 at an internal electric field of 105 kV/cm), they operated as spectroscopic photon counting soft X-ray detectors uncooled at 30 ℃. The measured energy resolution (FWHM at 17.4 keV, Mo Ka) varied from 1.36 to 1.68 keV among different diodes.