Confirmation of Tunneling Current via Traps by DLTS Measurements in InGaAs Photodiodes

Abstract

A detailed analysis of the reverse characteristics of In 0.53 Ga 0.47 As pin-photodiodes at various temperatures reveals, besides generation, diffusion and band-to-band tunneling of carriers, an additional contribution to the dark current due to tunneling through an energy barrier of 0.16±0.02 eV. In deep-level transient spectroscopy measurements a thermal activation energy of 0.57±0.01 eV, equal to the gap energy minus the tunneling barrier, has been found. From these two measurements it can be concluded that thermal activation of deep traps and subsequent tunneling of carriers into band states leads to the additional dark current component.