Silicon Carbide Power Diodes as Radiation Detectors
We have tested the radiation detection performance of Silicon Carbide (SiC) PIN diodes originally developed as high power diodes. These devices consist of 100 micron thick SiC grown epitaxially on SiC substrates. The size and thickness of the devices make them appropriate for a number of radiation detection applications. We tested 0.25 cm2 and 0.5 cm2 devices and obtained X-ray spectra under illumination with an Am-241 radioactive source. The spectra showed an energy resolution that was consistent with the resolution expected for the large capacitance of the device. Smaller devices with a diameter of 1 mm were also tested and produced spectra with a room temperature energy resolution of ~550 eV, which is consistent with the electronics limit for the capacitance of the small device. We measured the absolute charge generated by X-rays per KeV in SiC by comparing the charge generation with similar silicon devices and determined the energy required per electron hole pair in SiC to be 8.4 eV. We also performed radiation damage tests on these devices and found no significant loss in charge collection up to a photon dose of 100 MRad. Applications for these devices can be found in the fields of particle physics, nuclear physics, nuclear medicine, X-ray fluorescence, X-ray astronomy and X-ray navigation.
Robert P. Devaty, David J. Larkin and Stephen E. Saddow
B. F. Phlips et al., "Silicon Carbide Power Diodes as Radiation Detectors", Materials Science Forum, Vols. 527-529, pp. 1465-1468, 2006