Influence of formation conditions of silicon diodes on their reverse currents

Abstract

In this work, a study was made of the influence of silicon diode manufacturing technology on the emergence of generation and recombination centers. The electrical characteristics of p-n junctions formed in different ways on n-type silicon substrates were compared: a) the p-type layer was created by the diffusion method; b) the p-type layer was formed by ion implantation into an epitaxial n-layer preliminarily grown on the substrate; c) two n- and p-type epitaxial layers were successively deposited on the substrate. It has been established that for diodes based on a double epitaxial layer, the direct and reverse current-voltage characteristics (CVC) are due to the diffusion mechanism, and the structures themselves have a low concentration of recombination centers. At the same time, in diodes based on the diffusion method and ion implantation, the CVCs are due to the generation-recombination mechanism. With reverse bias, electron-phonon processes play a significant role in the formation of the CVC, and with forward bias, carrier recombination in the region of the space charge of the p-n junction. The concentrations and energies of recombination centers have been determined. Keywords: forward and reverse current-voltage characteristic, p-n junction, diffusion, ion implantation, epitaxy, recombination centers, the Poole--Frenkel effect, electron-phonon interaction.