氮氧化鉭薄膜於電阻式記憶體的製作與轉態特性之研究

Abstract

由於近幾年來，非揮發性記憶體的研究與發展備受關注，又因為傳統浮閘快閃記憶體無論在垂直或水平微縮上受到挑戰，所以發展新穎式的非揮發性記憶體是重要的趨勢。其中又以電阻式非揮發性記憶體元件具有低耗損能量、低操作電壓、高記憶密度、且具快的操作速度快以及高耐久度等優點，最重要的是結構簡單(金屬/介電質/金屬) ，使其成為最具有取代快閃記憶體的新穎式非揮發性記憶體元件。 在本篇論文中，主要是研究探討氮化鈦/氮氧化鉭/白金結構與氮化鈦/氮氧化鉭/銅結構的電阻式記憶體的轉態特性探討和電流傳導物理機制。其實驗內容主要可以分為四大部分，第一部份為白金上電極結構元件的二極性基本電性與轉態機制研究，且強調正負形成電壓的機制差異。第二部份為銅上電極結構元件的二極性基本電性與轉態機制研究。第三部份為利用變溫、定電流等量測方式來證明兩元件的轉態機制與差異，探討在薄膜內轉態的情形以及上電極對轉態有甚麼影響。第四部份為兩元件的單極性基本電性與轉態機制研究，並與雙極性轉態機制做比較。

Recently, there are intensive researches and development of various non-volatile memories gradually. Because the traditional floating gate flash memory in terms of vertical or horizontal scaling is being challenged. One of the most important advanced memories is the resistance random access memory (RRAM). The device has the advantages of low power consumption, low operating voltage, high density, fast speed and high endurance and retention. The most important attribute of the device is that it has a simple structure (metal / dielectric / metal).Thus, we may eventually replace Flash memory with RRAM for non-volatile memory application. This thesis is the studying the resistive switching properties and the physical mechanism of current conduction of structure of titanium nitride / tantalum oxynitride / platinum and the structure of titanium nitride / tantalum oxynitride / copper . The content can be divided into four parts. In part one, we study the bipolar resistive switching characteristic of structure TiN/TaON/Pt, and propose a model which oxygen ions migration makes the device’s resistance switched and focus on positive and negative Forming explanation. In part two, we change top electrode to copper and study the bipolar resistive switching characteristic of structure TiN/TaON/Cu. We also propose a model which copper ions redox and electron-migration makes the device’s resistance switched. In part three, we use many experiments like temperature measurement, constant current stress measurement to prove two devices’ mechanisms. With different methods we study the resistive switching phenomena in film and what effect will happen in different top electrode. In final part, there is unipolar characteristic in two devices and we explain resistive switching mechanism of two devices as well.