本文選題：阻變存儲器 + 單極性阻變��； 參考：《湘潭大學》2014年碩士論文

【摘要】：依賴于高速度、大容量、低功耗非揮發(fā)性存儲器的信息技術(shù)正快速的發(fā)展。Flash存儲是當前的主流，具有很高的容量，但速度慢并且逐漸接近尺寸可伸縮性的物理極限。為了未來信息存儲的需要，新興的非揮發(fā)性存儲，如相變存儲器(PRAM)、鐵電存儲器(FRAM)、磁變存儲器(MRAM)及阻變存儲器(RRAM)最近幾年得到廣泛的研究。在這些候選者中，阻變存儲器具有出色的優(yōu)點，如高響應速度、長保持性、多值存儲和低功耗，以及更好的伸縮性和與傳統(tǒng)的CMOS工藝相兼容；被認為是下一代非揮發(fā)性存儲器的最佳候選者。許多的過渡金屬氧化物，如ZnO、TiO2、ZrO2、MnO2、和NiO等具有可重復的阻變特性，其中，氧化鋅被廣泛的探索，，是因為其具有組份簡單、清晰的轉(zhuǎn)變特性、低的轉(zhuǎn)變電壓、較高的開關(guān)比值且通過不同的摻雜可調(diào)節(jié)其電學特性。本論文選擇氧化鋅阻變存儲器為研究對象，利用溶膠-凝膠(Sol-Gel)法來制備不同摻雜的ZnO薄膜器件，主要探索了不同的器件結(jié)構(gòu)和測試條件對其阻變極性的影響，具體工作內(nèi)容概括如下： 1.采用不同的頂電極(Pt or Ag)，Metal/La-doped ZnO/Pt三明治結(jié)構(gòu)被構(gòu)造，單極性阻變行為和雙極性阻變行為分別在Pt/La-doped ZnO/Pt和Ag/La-doped ZnO/Pt結(jié)構(gòu)器件中獲得。比起不摻雜的氧化鋅器件(Pt/ZnO/Pt和Ag/ZnO/Pt)，鑭摻雜的器件具有良好的阻變均一性，如狹窄分布的阻變參數(shù)、更高的開關(guān)比、更好的保持性和急劇的轉(zhuǎn)變特性。進一步地我們制備了Pt/La-doped ZnO/ZnO or SrTiO3/Pt結(jié)構(gòu)器件，其中ZnO和SrTiO3作為緩沖層，并且發(fā)現(xiàn)不同的阻變行為依賴于不同的緩沖層。穩(wěn)定的單極和雙極阻變行為可分別在具有ZnO和SrTiO3緩沖層的結(jié)構(gòu)器件中展現(xiàn)。相比Pt/ZnLaO/Pt結(jié)構(gòu)器件，通過嵌入緩沖層，器件展現(xiàn)出更加良好的阻變特性； 2.單極和雙極模式的共存現(xiàn)象也在釩摻雜的氧化鋅器件中觀察到，在第一次電壓掃描的過程兩種模式可分別在不同的限制電流下被激活，0.1mA的限制電流下器件展現(xiàn)出可重復的雙極阻變行為，10mA的限制電流下呈現(xiàn)出單極阻變行為；兩種阻變模式之間的轉(zhuǎn)變是可逆的，值得注意的是在這樣的轉(zhuǎn)變中可實現(xiàn)三種邏輯狀態(tài)； 3.單極和雙極模式的共存也在Pt/Zn0.99Zr0.01O/Pt結(jié)構(gòu)器件中觀察到，激活(Forming)過程之后，器件具有單極阻變行為，在Reset過程中若同向掃描測試器件呈現(xiàn)出單極阻變行為，若反向測試時則為雙極阻變行為；對于雙極性阻變模式，通過施加不同的限制電流或者不同的掃描電壓范圍可在器件的低、高阻態(tài)分別實現(xiàn)可控的多態(tài)阻值，類似的結(jié)果也在亞微米結(jié)構(gòu)器件中被發(fā)現(xiàn)(200ns的脈沖測試下各個阻態(tài)分別可重復104次)。
[Abstract]:Information technology, which relies on high speed, large capacity, low power and non-volatile memory, is developing rapidly. Flash memory is the mainstream, with high capacity, but slow speed and approaching the physical limit of dimensional scalability. In order to meet the needs of future information storage, new non-volatile memory, such as phase change memory (PRAM), ferroelectric memory (FRAM), magnetic variable memory (MRAM) and resistive memory (RRAM), have been extensively studied in recent years. Among these candidates, resistive memory has excellent advantages, such as high response speed, long retention, multi-value storage and low power consumption, better scalability and compatibility with traditional CMOS processes; It is considered to be the best candidate for next generation non-volatile memory. Many transition metal oxides, such as ZnOOTiO2O2ZrO2MnO2and NiO, have repeatable resistance properties, among which zinc oxide has been extensively explored because of its simple composition, clear transition characteristics, low transition voltage, etc. The electrical properties can be adjusted with higher switching ratio and different doping. In this paper, zinc oxide resistive memory is chosen as the research object, and different doped ZnO thin film devices are fabricated by sol-gel method. The effects of different device structures and test conditions on the resistance polarity are mainly explored. Specific work can be summarized as follows: 1. Different top electrode Pt or Agna / Metal- / La-doped ZnO/Pt sandwich structures were constructed, and unipolar and bipolar resistive behaviors were obtained in Pt/La-doped ZnO/Pt and Ag/La-doped ZnO/Pt structures, respectively. Compared with undoped zinc oxide devices such as Pt / ZnO / Pt and Ag / ZnO / PT, lanthanum doped devices have good resistance uniformity, such as narrow distribution of resistive parameters, higher switching ratio, better retention and sharp transition characteristics. Furthermore, we have fabricated Pt/La-doped ZnO/ZnO or SrTiO3/Pt devices with ZnO and SrTiO3 as buffer layers, and it is found that different resistive behaviors depend on different buffer layers. Stable monopole and bipolar resistive behaviors can be demonstrated in structures with ZnO and SrTiO3 buffer layers, respectively. Compared with Pt/ZnLaO/Pt devices, the devices exhibit better resistive characteristics by embedding the buffer layer. 2. The coexistence of unipolar and bipolar modes is also observed in vanadium doped zinc oxide devices. In the process of the first voltage scan, the two modes can be activated under different limiting currents, respectively, and the devices exhibit repeatable bipolar resistive behavior at the limiting current of 0.1mA. The devices exhibit unipolar resistive behavior under the limited current of 10mA. The transition between the two resistance modes is reversible, and it is worth noting that three logical states can be realized in such a transition. 3. The coexistence of unipolar and bipolar modes is also observed in Pt/Zn0.99Zr0.01O/Pt structure devices. After activating the forming process, the devices exhibit unipolar resistive behavior, and the unipolar resistive behavior is observed in the Reset process if the device is tested in the same direction. For the bipolar resistance mode, the controllable polymorphic resistance can be achieved in the low and high resistance states by applying different limiting current or different scanning voltage range. Similar results have also been found in sub-micron devices with pulse measurements of 200 ns, each resistive state can be repeated 104 times respectively.
【學位授予單位】：湘潭大學
【學位級別】：碩士
【學位授予年份】：2014
【分類號】：TP333;O484.4

【參考文獻】

相關(guān)期刊論文 前2條

1 胡光輝;溶膠-凝膠技術(shù)研究及其應用[J];重慶工業(yè)高等�？茖W校學報;2005年01期

2 劉維紅;胡曉云;張錦;張德愷;;脈沖激光沉積法制備無機發(fā)光薄膜的研究現(xiàn)狀[J];激光與光電子學進展;2006年12期

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