Silicon Carbide Radiation Micro-Detectors for Harsh Environments

Silicon Carbide (SiC) is a wide bandgap semiconductor with outstanding physical properties for manufacturing detectors of ionizing radiation (alpha, electrons, protons, X and gamma rays). The wide band gap (up to 3.2 eV), high saturation velocities of the charge carriers (2x10 7 cm/s), high breakdown field (2 MV/cm), high thermal conductivity (4.9 W/cm 2 ) and its radiation hardness, allow low-noise and reliable operation in environments which are critical or forbidden to other semiconductor detectors. In the last ten years, considerable R&D efforts have been devoted worldwide to growth and process technologies which have made available high purity epitaxial 2" and 3" SiC wafers. The state of the art of SiC micro-detector manufacturing technology will be presented together with prototype detectors with high resolution spectroscopic capabilities and outstanding low noise performance at room and high temperatures. The experimental characterization of different detector types (pad, pixel and microstrip) is shown and the radiation hardness of SiC detectors is discussed. X-ray spectroscopy with SiC will be presented: intrinsic line widths of 232 eV FWHM at +29°C and 336 eV FWHM at +100°C have been obtained using a SiC microstrip detector with 32 strips, 2 mm long and 25 μm, the recorded performance being fully limited by the noise of the front-end electronics. The necessity and the limits of ultimate low-noise front-end for reading out the Fano-limited SiC detectors are discussed.