釩摻雜與快速熱退火應用於以濺鍍法製備之鋯酸鍶記憶體元件電阻轉換特性研究

Abstract

電阻式記憶元件能成為下一世代非揮發性記憶體之候選人，因為其具有簡單的元件結構、低操作電壓、低功率損耗、資料存取時間長、元件面積小、高操作速率、低製作成本、穩定的資料寫入抹除及非破壞性讀取特性等優點。 本論文利用鈣鈦礦結構材料（鋯酸鍶）作為電阻式記憶體的材料，首先本論文將介紹新世代非揮發性記憶體之應用、特性以及優點，本論文中也將探討各種可能的電阻轉換機制及傳導機制。在實驗的部分，我們利用射頻磁控濺鍍法製備純鋯酸鍶與釩摻雜鋯酸鍶薄膜作為轉換電阻層，且利用此濺鍍法沉積鎳酸鑭作為幫助鋯酸鍶成長優選方向之緩衝層，底電極白金及頂電極鋁則利用蒸鍍法製備，形成一頂電極/電阻層/緩衝層/底電極的結構。首先，我們將探討釩摻雜對鋯酸鍶薄膜轉態特性之影響，第二部份將鋯酸鍶薄膜利用快速熱退火改善其電阻轉換特性並趨於穩定，同時也比較及探討不同快速熱退火條件對記憶體元件特性的影響，更進一步由實驗結果來探討可能的電阻式記憶體的電阻轉換及傳導機制，其中之物理機制與電阻轉換特性將於第三章探討。

The resistive random access memory (RRAM) has potential to be next-generation nonvolatile memory (NVM) because of its ascendant advantages such as simple device structure, low operation voltage, low power consumption, long retention time, small cell size, high operation speed, low cost, good endurance, and non-destructive readout. In this thesis, the RRAM devices manufactured based on SrZrO3 (SZO) thin films are studied and developed. At first, I will introduce the applications, fundamental characteristics, and advantages of next-generation nonvolatile memories. The conduction mechanisms of RRAM that have been published are also discussed. In experimental details, pure-SZO and V2O5 doped SZO film was deposited on the LaNiO3 buffer layer by RF magnetron sputter. Pt and Al act as bottom electrode and top electrode, respectively. Therefore, electrode/resistive thin film/buffer layer/electrode structure is formed. First, we will discuss the influence of V-doping effect. Second, we use thermal treatment to improve and stabilize the switching property by rapid thermal annealing on SZO film. The effects of resistive switching property by different rapid thermal treatment condition are also compared and discussed. The possible resistive switching mechanism based on the research results is also discussed in chapter 3.