Comparison of bulk and epitaxial 4H-SiC detectors for radiation hard particle tracking

Measurements and simulations have been carried out using bulk and epitaxial SiC detectors. Samples were irradiated to fluences of around 10¹⁴ hardrons/cm². Material of thickness 40μm gave a charge collection efficiency of 100% dropping to around 60% at 100 μm thickness. Detailed MEDICI simulations incorporated the main defect levels in SiC, the vanadium center, Z-center and a mid-gap level as measured by deep level transient spectroscopy and other techniques. Calculated recombination currents and charge collection efficiencies at varying fluences were comparable to experimental data. The study suggests that SiC detectors will operate up to fluences around 10¹⁶/cm² as required by future particle physics experiments.