Resistive Switching Characteristics and Failure Analysis of TiO2 Thin Film Deposited by RF Magnetron Sputtering System

Abstract

The effect of the postannealing conditions of TiO2 thin films deposited using a radio frequency (rf) magnetron sputtering system on their electrical resistive switching characteristics was evaluated in the Pt/TiO2/Pt structure, and the compositional change of the TiO2 thin films after resistive switching failure was investigated. The Pt/TiO2/Pt structure with polycrystalline TiO2 showed a relatively more stable set/reset voltage dispersion and resistance difference between the high resistance state (HRS) and low resistance state (LRS) than those with amorphous TiO2. In the energy dispersive X-ray spectroscopy analysis of the TiO2 thin film in Pt/TiO2/Pt with reset-stuck failure, in which the resistive switching from the HRS to the LRS failed after repeated resistive switching, the peak intensity of oxygen was significantly decreased compared with that before resistive switching and the decrease of the oxygen content was more noticeable near the top electrode than near the bottom electrode. Consequently, it is considered that the depletion of oxygen in the TiO2 thin film after multiple resistive switching cycles by successive voltage sweeping could be one of the main causes of the resistive switching failure phenomenon. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3526316] All rights reserved.