Deep energy levels in power diodes introduced by iridium diffusion

Abstract

The results of a study carried out on N-type silicon and P +PNN + silicon diodes diffused with iridium at temperatures ranging from 820 to 940°C are reported. The iridium-related deep energy levels were measured using DLTS method. The energy levels E c = 0.16, 0.28 and 0.54 eV were found, the dominant recombination centre is of energy E c − 0.28 eV. Besides the energy levels, the influence of iridium diffusion on carrier lifetime and basic parameters of the diode structures was studied. It was found that iridium diffusion may be used successfully for the fabrication of fast, soft reverse recovery power diodes.