二氧化鈦電阻式記憶體之特性

Characteristics of TiO2 Resistive Random Access Memory

在本論文中，利用射頻磁控濺鍍技術分別在Pt/Ti/SiO2/Si 與ITO/Glass 基板上沉積兩種二氧化鈦金屬/絕緣體/金屬電阻式記憶體結構。並探討其電阻轉換機制及其高低電阻態之漏電行為。在物性研究方面，藉由X 光繞射儀、電子顯微鏡等儀器來分析二氧化鈦薄膜的結晶性與表面微結構。此外在電特性分析方面，採用半導體參數分析儀來量測金屬氧化物薄膜的電流對電壓(I-V)特性、電流密度對電場(J-V)特性等。由實驗結果得知，TiO2 型ITO/Glass 基板電阻式記憶體之最小操作電壓大約為2 V 而開關比(ON/OFFratio)大約為2。但是TiO2 型Pt/Ti/SiO2/Si 型基板電阻式記憶體卻有較佳的最小操作電壓大約為0.6 V 而開關比亦大約為2。最後，此TiO2 型電阻式記憶體之低阻態漏電流行為歐姆接觸，但其高阻態的漏電流行為是類似於F-N 穿隧。

In this study, the electrical and physical properties of TiO2 thin films deposited on Pt/Ti/SiO2/Si and ITO/glass substrates in metal/insulator/metal (MIM) structure for applications in resistive random access memory (RRAM) devices were presented and investigated. For the physical characteristics, the crystallization and surface microstructure of the TiO2 thin films were obtained by XED and SEM morphology. For the electrical characteristics, the leakage current I-V and J-E characteristics of the resistive random access memory were measured using by the semiconductor parameter. From the experimental results, the operating voltage of the TiO2 resistive random access memory for Pt/Ti/SiO2/Si and ITO/glass substrates were 0.6 and 2 V, respectively. The on/off current ration of TiO2 resistive random access memory for Pt/Ti/SiO2/Si and ITO/glass substrates all were about 2. Finally, the resistance switching mechanisms and leakage current behaviors between high resistance state and low resistance state were investigated. The current mechanisms of TiO2 resistive random access memory for low and high resistance leakage current states were Ohmic contact and Fowler-Nordheim tunneling mechanism.