Influence Of Crystal Structure And Interface Modification On Resistance Switching Properties In TiO₂films

With the development of science and information technology, people have higher requirements to the information storage, such as higher storage density. The Resistive Random Access Memory (RRAM) is based on Electric-pulse-induced resistive switching (EPIR) phenomenon in metal/oxide/metal structure. It has attracted scientist’s great attention for its superior characteristics and the compatibility with CMOS process. It has become one of the best choices for next generation of memory devices. It is a hot issue in physics and material science.This thesis investigates the influnce of crystal structure and interface modifications on resistive switching properties of Ag/TiO2/Pt heterostructrues. The main results are as follows:1. The influence of crystal structural of the insulating layer on resistive switching performance. We prepared TiO2thin films with different structures using different methods, including amorphous, anatase, mixed phase and rutile. The resistive switching properties of these four heterostructrues are consistant with the filaments mechanism. All these devices showed resistive switching properties with a certain endurance and retention. Among them, the anatase sample showd a better performance with a retention of>12K and a relatively good endurance.2. The influence of Au nanodots between bottom electrode and TiO2film on resistive switching performance of Ag/TiO2/Pt heterostructrues.To overcome the instability of conduction filaments between the top electrode and bottom electrode, we control the local electric field by implanting Au nanodot with different sizes between bottom electrode and TiO2film. By using this method, the performance of the Ag/TiO2/Pt heterostructrues has been improved greatly, and it is conducive to practical application. Furthermore, we investigated the influence of the size of Au nanodots on the performance of the devices. The size of the Au nanodots is controled by adjusting the sputtering time. We found that the best performance of the device can be obtained using the sputtering time of20second.