The charged particle response of silicon carbide semiconductor radiation detectors

Silicon carbide (SiC) radiation detectors are being developed for high-temperature applications in harsh radiation environments. The wide band gap of SiC (3.25 eV) compared to conventional semiconductors such as silicon (1.1 eV) and the relatively high-radiation resistance of SiC make it a semiconductor, that is highly suited for such applications. In this paper, we report on charged particle response measurements with larger-sized diodes. The charged-particle response characteristics of these diodes were tested with 238Pu, 242Pu and 148Gd alpha-particle sources in air. Energies deposited by alpha particles from these sources were calculated using the SRIM range-energy code. The peak shapes are nearly Gaussian, with a full-width at half-maximum for 148Gd of 89.5 keV corresponding to 1562 keV deposited in the detector active volume. This measured resolution is greater than, but still comparable to, the resolution obtained with silicon alpha spectrometers. Range straggling for the energy fraction deposited in the 10-μm thick active layers contributes significantly to our observed energy resolution. Design parameters for an optimum SiC alpha spectrometer are discussed.