Effect of Irradiation with Fast Neutrons on Electrical Characteristics of Devices Based on CVD 4H-SiC Epitaxial Layers

摘要

The effect of irradiation with 1-MeV neutrons on electrical properties of Al-based Schottky barriers and p~+-n-n~+ diodes doped by ion-implantation with Al was studied; the devices were formed on the basis of high-resistivity, pure 4H-SiC epitaxial layers possessing n-type conductivity and grown by vapor-transport epitaxy. The use of such structures made it possible to study the radiation defects in the epitaxial layer at temperatures as high as 700 K. Rectifying properties of the diode structures were no longer observed after irradiation of the samples with neutrons with a dose of 6 * 10~(14) cm~(-2); this effect is caused by high (up to 50GΩ) resistance of the layer damaged by neutron radiation. However, the diode characteristics of irradiated p~+-n-n~+ structures were partially recovered after an annealing at 650 K.