Effect of Low-Dose Proton Irradiation on the Electrical Characteristics of 4H-SiC Junction Diodes

Abstract

The effect of low-dose proton irradiation (irradiation dose 10¹⁰–1.8 × 10¹¹ cm^–2) on the capacitance–voltage, forward current–voltage, and reverse-recovery characteristics of 4H-SiC p–n_o junction diodes is studied. Irradiation is performed with 1.8-MeV protons through a 10-μm-thick Ni-film (the proton energy and Ni-film thickness were chosen so that the projected proton range in silicon carbide is approximately equal to the p–n_o junction depth). It is shown that proton irradiation in the above doses (i) does not change the concentration of majority carriers, (ii) leads to a dramatic decrease in the lifetime of nonequilibrium carriers (at a low injection level) (by several tens of times at the highest irradiation dose), and (iii) decreases the reverse-recovery charge at a high injection level (by up to a factor of 3 at the highest irradiation dose).