Detection of fast neutrons using 4H-SiC radiation detectors

Abstract

The particle detector based on a low concentration 4H-SiC epitaxial layer shows promising properties for the detection of various types of ionizing radiation. The wide bandgap energy of the 4H-SiC semiconductor material (3.23 eV at room temperature) allows the detector to operate reliably at room temperature and at elevated temperatures up to several hundred degrees Celsius. The 80 >m thick 4H-SiC epitaxial layer grown on a 350 >m 4H-SiC substrate was used for detector preparation. The active area of the detector was defined by a 3 mm Schottky contact. The current-voltage measurement shows a reverse current of less than 30 pA up to 1000 V. Capacitance-voltage measurements show that the epitaxial layer is completely depleted at bias voltages above 250 V. The detector has been tested with neutrons of energies from 370 keV up to 14.9 MeV. Neutrons were produced by three nuclear reactions p-T, d-D and d-T. The measured spectra clearly identified the elastic and inelastic scattering at silicon and carbon atoms of detector material.

Keywords

• 4h-sic detector
• low concentration sic epitaxial layer
• fast neutron detection