Analysis of Alpha Spectra for SiC Neutron Detectors due to their Structural Differences

The harsh radiation environments such as a nuclear reactor core, high-energy physics experiments, or outer space can cause radiation damage to semiconductor radiation detectors. But, semiconductor radiation detectors based on silicon carbide (SiC), aluminum nitride (AlN), and boron nitride (BN), which have large energy band gap, are the most promising ionizing radiation detectors for high temperature and in harsh radiation fields. SiC semiconductor high bandgap energy (from 2.2 to 3.2 eV for the most common polytypes) and high displacement threshold energy (21.8 eV) should lead to a radiation detector capable of operating at high temperature and in harsh radiation fields. Semiconductor radiation detectors based on PIN-type SiC were fabricated in two types for detection fast neutron and thermal neutron. For thermal neutron detection, 6LiF were evaporated on the surface of a SiC semiconductor. In this study, 5.5 MeV alpha spectra were measured with two types of SiC neutron detectors. And alpha responses were also analyzed due to their structural differences as preliminary test of neutron detection. Two types of SiC neutron detectors were designed and fabricated. Alpha particles were well detected even if zero detector bias. Low energy peak was observed in case of a SiC thermal neutron detector due to ⁶LiF. To apply the fabricated SiC detectors in harsh environment, radiation hardness and neutron response are scheduled to study.