GaN metal–semiconductor interface and its applications in GaN and InGaN metal–semiconductor–metal photodetectors

Abstract

A detailed study of Schottky barrier contact on n-type GaN and the characterisation of GaN metal–semiconductor–metal photodetectors is reported. Au, Pd, Ni, Pt and Ti were used as Schottky dots and Al was used as an ohmic contact. The barrier, ideality factors and effective Richardson constant were obtained. The large index of interfacial behaviour, S, reveals that the surface pinning of n-GaN is much less than that of GaAs, GaP and Si. Interdigital metal–semiconductor–metal (MSM) photodetectors were fabricated by depositing different metal contacts on n-GaN, p-GaN and n-In0.2Ga0.8N. The characteristics of the fabricated Schottky MSM photodetectors were studied in detail.