新穎透明電阻式記憶體元件於高密度與低功率消耗的非揮發性記憶體應用

Abstract

隨著近年來消費性電子產品，如：智慧型手機、智慧型平面顯示器、筆記型電腦、MP3 和數位相機等，需求與日俱增，非揮發性記憶體已成為現今半導體工業研發重點之一。其中電阻式記憶體元件具結構簡單、元件尺寸小、低功率消耗與操作速度快速等特點，極有可能取代現今主流的快閃式記憶體(Flash Memory)，相當具有潛力成為下世代具三維度立體堆疊結構的高元件密度的非揮發性記憶體。為了整合平面顯示器與記憶元件於玻璃基板達到系統面板(system on panel：SOP)的目標，具透明結構的記憶體元件與周邊電路的研究，是非常急迫且重要的課題。因此本計畫的構想是以高密度與低功率的透明電阻式記憶體元件為基礎，利用本研究團隊既有的場效電晶體搭配電阻式記憶體結構(1T1R)與氧化物二極體搭配電阻式記憶體結構(1D1R)製造技術，進行元件奈米結構與三維度積體電路(3D-IC)應用的研究。 在此三年計畫中，第一年計畫主要工作為透明電阻式記憶體元件之製作，利用高度次序與高密度的氧化鋅(ZnO)奈米線薄膜結構與其他透明氧化物材料當作電阻轉態層來提升元件的記憶體特性，搭配不同的透明電極材料，製作於矽基板、玻璃基板、石英基板與可撓曲的塑膠基板上，研究探討不同透明電極材料組合之電阻式記憶體的電阻轉態機制與材料特性相依性。第二年計畫將根據本實驗室先前所發表的1T1R與1D1R技術，配合第一年研究的最佳化條件透明電阻式記憶體為基礎，探討1T1R與1D1R結構之整體電性影響。另外，製作具交叉條狀(Cross-bar)結構的透明電阻式記憶體陣列(Array)，進行陣列操作機制、透光率與撓曲率的研究。在第三年的研究中，將整合1T1R與1D1R的結構，搭配不同層數的交叉條狀記憶陣列，達到垂直延伸，高元件密度的三維度積體電路結構，進行記憶體特性效能與可靠度(Reliability)的測試。

Nonvolatile memory (NVM) technology plays a crucial role in the semiconductor industry, due to the rapid progress of portable electronic devices. Nowadays, the mainstream of this technology is flash memory which is based on charge storage and this technology is rapidly reaching its physical limits. Resistive random access memory (RRAM) has several advantages, such as simple constituents, small size, low power consumption, high operation speed and high density. The RRAM using transition metal oxides is one of the most promising emerging technologies than the others for future applications. On the other hand, for next generation display industry, all of active elements and peripheral circuit will fabricate on the same substrate. Therefore, it is important to investigate the transparent electronics to bring the era of system on panel (SOP) technology. Hence, we propose to combine the high density and low power transparent RRAM array with a transistor to form one transistor one resistor structure (1T1R) and transparent RRAM with an oxide diode to form one diode one resistor (1D1R) for 3-dimensional (3D) integrated circuit (IC) applications. First year of this three years project, we will fabricate the novel flexible and transparent RRAM devices using transparent and high density nanowires zinc oxide (ZnO) film as an active layer with different transparent electrodes on Si, glass, quartz or flexible polymer substrate. In the second year, we will study the resistive switching properties of different transition metal oxides grown by physical techniques using cross bar memory structures array. In addition, we will study switching properties of the fabricated 1T1R and 1D1R structures. In the final year, we can combine the transparent RRAM cross bar array with 1T1R and 1D1R structure for high density 3D-IC applications. The details operational mechanism and reliability of this 3D-IC RRAM structure will be investigated in this project.