Silicon Schottky barrier photodiodes with a thin AlN nucleation layer

Abstract

PurposeThe purpose of this paper is to present the characteristics of novel silicon Schottky barrier (SB) photodiodes (PDs) with aluminium nitride (AlN) (100 nm) nucleation layer.Design/methodology/approachComparison was made with conventional silicon SB PDs.FindingsIt was found that smaller dark current could be achieved with AlN nucleation layer. It was also found that effective SB height increased from 0.65 to 0.71 eV with the insertion of the AlN layer. The dark leakage current for the Schottky PDs with the AlN layer was shown to be about two orders of magnitude smaller than that for the conventional silicon SB PDs.Research limitations/implicationsIt is possible that the detrimental effect of interface states situated near the metal semiconductor interface was less pronounced for the sample owing to the insertion of the AlN nucleation layer.Originality/valueThere is believed to be no other report on silicon SB PDs capped with an AlN layer in the literature. This paper describes the fabricated silicon SB PDs and reports on the electrical characteristics of the devices with an AlN nucleation layer grown at low temperature.