SiC X-ray detectors for spectroscopy and imaging over a wide temperature range

The advantages of using Silicon Carbide for X-ray spectroscopy and imaging has been examined over the existing semiconductor detectors. Several SiC detectors have been manufactured and tested. They are constituted by Schottky junctions on a low doped (5 x 1014) n-4H-SiC epitaxial layer. The diodes show extremely low reverse current densities at room temperature (≤5 pA/cm2) up to mean electric field of 100 kV/cm in the depleted region. These currents are two order of magnitude lower with respect to the best junctions on Silicon used for X-ray spectroscopy, so making SiC detectors extremely low noise devices. Using a pixel detector a noise of 415 eV FWHM at room temperature has been measured. Moreover for the first time an X-ray spectroscopy at high temperature has been demonstrated using a semiconductor: the SiC detector has been operated at 100 C, showing a noise of 1 keV FWHM. (orig.)