Origin of Hysteresis in Zinc Oxide Based Metal Oxide Semiconductor Films
Author: S. K. Nandi
Category: Engineering, Science and Mathematics
Abstract:
Zinc oxide is a unique material that exhibits semiconducting and piezoelectric dual properties. Interfacing of oxide and semiconductor materials provides a means of coupling unique properties associated with oxide materials to high performance semiconductor devices. To function at low biases to minimize power consumption, such devices must also contain a high-mobility semiconductor and/or a high-capacitance gate oxide. In this work we ovserve the crystal quality and composition of the deposited films with atomic force microscopy (AFM), scanning electron microscopy (SEM), Rutherford backscattering (RBS) and X-ray photoelectron spectroscopy (XPS) and electrical properties of SiO2/ZnO heterostructure, where SiO2 is used as oxide. Metal-Oxide-Semiconductor structures demonstrate hysteresis characteristic. The metal-SiO2-ZnO capacitor structures demonstrate a characteristic metal-insulator-semiconductor capacitance-voltage (C-V) behaviour with a hysteretic memory window of approximately 0.12 V. The appearance of a broad hysteresis and the significant shift in the flatband voltage indicate the presence of a large number of trapped charges at the interfaces.
Keywords: Zinc Oxide; Metal Oxide Semiconductor; XPS; RBS; SEM.