Fabrication and characterization of Schottky diode on ultra thin ZnO film and its application for UV detection

In this paper we report a Schottky contact based UV detector over ultrathin (∼25 nm) radio frequency (RF) sputtered ZnO thin film probably for the first time. The substrate used was IC compatible p-type silicon instead of widely used sapphire substrate. The surface morphology, crystal phases, optical properties of the thin film were studied by atomic force microscopy, Field emission scanning electron microscopy, x-ray diffraction and photo luminance. The planner Schottky diode (Pd/ZnO/Ti/Au) was fabricated by photolithography e-beam evaporator and DC sputtering. The electrical properties of the diode were investigated by semiconductor parameter analyzer with micro probing arrangement. Different parameters of the diode like barrier height, ideality factor and reverse saturation current were estimated from I-V characteristics using the Schottky Barrier Height theory. UV light of fixed frequencies and intensity were exposed on the diode and it was found that its different parameters were changed.