Optical and electrical properties of 4H-SiC irradiated with fast neutrons and high-energy heavy ions

Abstract

Photoluminescence and deep-level transient spectroscopy are used to study the effect of irradiation with fast neutrons and high-energy Kr (235 MeV) and Bi (710 MeV) ions on the optical and electrical properties of high-resistivity high-purity n-type 4H-SiC epitaxial layers grown by chemical vapor deposition. Electrical characteristics were studied using the barrier structures based on these epitaxial layers: Schottky barriers with Al and Cr contacts and p +-n-n + diodes fabricated by Al ion implantation. According to the experimental data obtained, neutrons and high-energy ions give rise to the same defect-related centers. The results show that, even for the extremely high ionization density (34 keV/nm) characteristic of Bi ions, the formation of the defect structure in SiC single crystals is governed by energy losses of particles due to elastic collisions.