Chin-Hsiang CHEN^*

Department of Electronic Engineering, Cheng Shiu University, Kaohsiung 830, Taiwan, R.O.C.

(Received June 1, 2010; Accepted November 17, 2010)

GaN ultraviolet (UV) Schottky barrier photodetectors (PDs) with a ZrO₂ or SiO₂ layer were successfully fabricated. With an appropriate ZrO₂ layer thickness, the dark current of Schottky barrier PDs could be notably suppressed, and the photogenerated carriers could still reach the electrodes by tunneling through the thin ZrO₂ layer under illumination. A UV-to-visible rejection ratio of more than one order of magnitude can be found in the Schottky barrier PD with ZrO₂ layers. It can be seen clearly that the cut-off occurred at approximately 360 nm while the responses above the band-gap were flat.

Key words: GaN, UV, photodetector, Schottky barrier

^*E-mail address: chchen@csu.edu.tw