Low Resistance Ohmic Contact on ZnO Thin Film Revealed by Schottky Barrier Height

Abstract

A high performance electronic device can be fabricated by achieving a high quality metal thin film Ohmic contact to intrinsic ZnO. In the present work, the low specific contact resistance Cr/Au metallization scheme deposited on n-type intrinsic 100 nm RF sputtered ZnO (Zinc oxide) thin film on SiO2/p-Si (100), an integrated circuit (IC) compatible substrate is utilized for the first time. Several metallization schemes were reported in the literature till date but not chromium to ZnO. Schottky Barrier height method was used to analyze the specific contact resistance which was obtained from the current-voltage characteristics. Thermionic emission carrier transport is considered at the interface for barrier height analysis. Low specific resistance was initiated in this work owing to the single-crystalline and smooth surface of the ZnO thin film revealed by X-Ray Diffraction (XRD) and Atomic Force Microscope (AFM) analysis. The simulation of the device structure was performed by using ATLAS software. The experimental result were finally compared with simulation results and were found to be in close agreement with each other.