【摘要】：近年來(lái)，由于存儲(chǔ)市場(chǎng)的巨大需求，非揮發(fā)性存儲(chǔ)技術(shù)發(fā)展迅速，基于浮柵結(jié)構(gòu)的傳統(tǒng)Flash存儲(chǔ)器在集成電路工藝中特征尺寸已經(jīng)接近甚至達(dá)到其物理極限，發(fā)展遇到瓶頸。在各種新型非揮發(fā)性存儲(chǔ)器中，阻變存儲(chǔ)器（RRAM）以其簡(jiǎn)單的存儲(chǔ)單元結(jié)構(gòu)、可縮小化的特征尺寸、極快的讀寫速度、很低的器件功耗、多值存儲(chǔ)潛力、可三維堆疊，以及低成本等特點(diǎn)，受到了廣大科研工作者的關(guān)注。本文主要研究一種與CMOS工藝兼容，制備容易的WOx基RRAM，探尋改善器件性能，降低器件功耗的方法，并對(duì)器件的阻變機(jī)制作了初步分析。 本文使用金屬鎢靶采用直流反應(yīng)磁控濺射沉積氧化鎢薄膜，并利用X射線衍射儀（XRD）、原子力顯微鏡（AFM）等手段對(duì)氧化鎢薄膜的結(jié)晶取向及表面形貌進(jìn)行了表征；使用半導(dǎo)體參數(shù)分析儀（SPA）對(duì)阻變單元的非揮發(fā)存儲(chǔ)特性進(jìn)行測(cè)試，通過(guò)對(duì)置位（SET）、復(fù)位（RESET）過(guò)程的I-V曲線進(jìn)行線性擬合結(jié)合電阻的溫度依賴性對(duì)氧化鎢薄膜的電阻轉(zhuǎn)變機(jī)制進(jìn)行了探索。 主要研究?jī)?nèi)容及結(jié)果如下： 1、基于氧化鎢材料制備了簡(jiǎn)單的Al/WOx/Cu結(jié)構(gòu)RRAM。WOx膜在300℃退火后，以（110）晶相的WO2.9為主。器件具有較好的雙極阻變特性，有較小的操作電壓（Vset=1.6V, Vreset=-0.9V）及超過(guò)三個(gè)數(shù)量級(jí)的阻變倍率。有較好的耐擦寫特性（1000cycles）、電阻保持性(10000S)。WOx薄膜中形成的Cu細(xì)絲及Cu細(xì)絲數(shù)量的變化是薄膜電阻轉(zhuǎn)變的主導(dǎo)機(jī)制。 2、通過(guò)對(duì)Cu下電極進(jìn)行熱氧化處理，制備了疊層結(jié)構(gòu)的Al/WOx/CuOx/Cu RRAM。與單層結(jié)構(gòu)相比，疊層結(jié)構(gòu)有更高的成品率，接近100%；更低、更一致的Forming電壓、SET、RESET電壓，更小的操作電流；器件的功耗降低了四個(gè)數(shù)量級(jí)以上。器件的電阻轉(zhuǎn)變機(jī)制為低阻態(tài)時(shí)阻變層中形成了Cu細(xì)絲，高阻態(tài)時(shí)Cu細(xì)絲與陰極接觸處部分?jǐn)嚅_(kāi)，在電極與阻變層界面處形成肖特基勢(shì)壘，器件的電流傳輸主要為肖特基發(fā)射。 3、在Cu下電極熱氧化處理時(shí)間為30S，WOx膜制取氧氬流量比為25:55sccm時(shí)，成功制備了單極型的Al/WOx/CuOx/Cu結(jié)構(gòu)RRAM。器件有較好的非揮發(fā)存儲(chǔ)特性，且是Forming-free器件。通過(guò)對(duì)電流的傳導(dǎo)機(jī)制進(jìn)行分析，發(fā)現(xiàn)低阻態(tài)時(shí)器件阻變層中形成了氧空位導(dǎo)電細(xì)絲，高阻態(tài)時(shí)氧空位導(dǎo)電細(xì)絲斷開(kāi)，器件的電流傳輸由空間電荷限制電流效應(yīng)（SCLC）主導(dǎo)。
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圖片說(shuō)明：MRAM單元的結(jié)構(gòu)示意圖
[Abstract]:In recent years, due to the huge demand of storage market, non-volatile storage technology has developed rapidly. The characteristic size of traditional Flash memory based on floating gate structure in integrated circuit technology has approached or even reached its physical limit, and the development has encountered a bottleneck. Among all kinds of new non-volatile memory, resistive memory (RRAM) has attracted the attention of many researchers because of its simple memory cell structure, reduced characteristic size, very fast reading and writing speed, low device power consumption, multi-valued storage potential, 3D stacking, and low cost. In this paper, a WOx-based RRAM, which is compatible with CMOS process and easy to fabricate is studied to explore the method of improving device performance and reducing device power consumption, and the resistance mechanism of the device is preliminarily analyzed. Tungsten oxide thin films were deposited by DC reactive magnetron sputtering with tungsten target. The crystallization orientation and surface morphology of tungsten oxide thin films were characterized by X-ray diffractometer (XRD), atomic force microscope (AFM). The non-volatile storage characteristics of resistance unit were tested by semiconductor parameter analyzer (SPA). The resistance transition mechanism of tungsten oxide thin films was explored by linear fitting of I 鈮，

本文編號(hào)：2512321