發(fā)布時間：2018-04-03 06:43

  本文選題：透明阻變存儲器　切入點(diǎn)：In-Ga-Zn-O　出處：《河北大學(xué)》2015年碩士論文

【摘要】：阻變存儲器(RRAM)因具有簡單結(jié)構(gòu)、低功耗和高速等優(yōu)點(diǎn)而受到廣泛關(guān)注。特別是透明阻變存儲器(TRRAM)兼?zhèn)涓咄该鞫鹊膬?yōu)點(diǎn)而引起人們興趣。具有自整流特性的阻變存儲器不僅可以實(shí)現(xiàn)高密度存儲而且能減小串?dāng)_的影響。同時,非晶銦鎵鋅氧(In-Ga-Zn-O)薄膜因具有遷移率高,工藝溫度低以及透明度高等特性而被廣泛研究。所以,本論文制備了雙極型的α-IGZO/Sr Ti O3/α-IGZO、高透明度的α-IGZO/Ga2O3/α-IGZO以及具有自整流特性的Ag/In-Ga-Zn-O/Pt阻變存儲器。并研究了器件的阻變性能和存儲機(jī)理。主要工作如下:采用磁控濺射和脈沖激光沉積(PLD)技術(shù)在石英襯底上制備了α-IGZO/STO/α-IGZO雙極型透明阻變存儲器。研究了器件的透過率、電流-電壓特性(I-V)、保持特性、抗疲勞特性以及導(dǎo)電機(jī)制。通過X射線衍射(XRD)觀察到薄膜均為非晶態(tài)。通過紫外分光光度計觀察到器件在可見光范圍內(nèi)的平均透過率為75%。器件的高阻態(tài)(HRS)和低阻態(tài)(LRS)的電阻比值為6,有效開關(guān)可操作250次以上。器件在經(jīng)過5×104s的測試后,高、低阻態(tài)的保持特性依舊保持穩(wěn)定。對器件的高、低阻態(tài)進(jìn)行擬合,表明導(dǎo)電機(jī)制以空間電荷限制電流(SCLC)為主。主要是由于陷阱俘獲和釋放電子影響了導(dǎo)電電子的變化,進(jìn)而使電流發(fā)生改變。采用磁控濺射技術(shù)制備α-IGZO/Ga2O3/α-IGZO結(jié)構(gòu)的透明阻變存儲器,中間介質(zhì)層選用透明性質(zhì)更優(yōu)秀的寬帶隙半導(dǎo)體材料Ga2O3。透明阻變存儲器在可見光范圍內(nèi)的平均光學(xué)透過率為91.7%(最大值為98.3%,最小值為81.3%),Ga2O3的光學(xué)帶隙為5.1e V。研究發(fā)現(xiàn)激勵電壓極性的不同,會影響器件中氧空位的分布,造成阻變特性曲線方向的不同。變溫測試透明阻變存儲器,擬合為跳躍電導(dǎo)機(jī)制。并得到高、低阻態(tài)的陷阱跳躍距離分別是1.4nm和0.7nm,高、低阻態(tài)的激活能為0.23e V和0.15e V�；贗n-Ga-Zn-O薄膜做中間介質(zhì)層制備的Ag/In-Ga-Zn-O/Pt阻變存儲器。研究發(fā)現(xiàn)器件在低阻態(tài)時,表現(xiàn)出自整流性質(zhì)。測試溫度范圍為303K-393K,器件的自整流性質(zhì)依舊保持穩(wěn)定。分別采用Cu,Ti和Ag作器件的上電極,自整流性質(zhì)隨電極功函數(shù)的變大而越發(fā)明顯。器件的電極尺寸影響電阻的變化。高阻態(tài)符合空間電荷限制電流機(jī)制,低阻態(tài)符合肖特基發(fā)射機(jī)制,變溫測試得到肖特基勢壘高度為0.32e V,動態(tài)介電常數(shù)εr為7.9。同時,研究認(rèn)為上電極與In-Ga-Zn-O界面的肖特基勢壘是產(chǎn)生自整流特性的主要原因。
[Abstract]:Resistive memory (RRAM) has attracted much attention because of its simple structure, low power consumption and high speed.In particular, transparent resistive memory (TRRAM) has the advantages of high transparency.Resistive memory with self-rectifying characteristics can not only achieve high density storage but also reduce crosstalk.At the same time, amorphous indium gallium zinc oxide In-Ga-Zn-O (In-Ga-Zn-O) thin films have been widely studied because of their high mobility, low temperature and high transparency.Therefore, the bipolar 偽 -IGZO / Sr TIO _ 3 / 偽 -IGZO, the transparent 偽 -IGZO / Ga _ 2O _ 3 / 偽 -IGZO and the self-rectifying Ag/In-Ga-Zn-O/Pt resistive memory have been prepared in this thesis.The resistance performance and storage mechanism of the device are also studied.The main work is as follows: 偽 -IGZO / 偽 -IGZO bipolar transparent resistive memory was fabricated on quartz substrate by magnetron sputtering and pulsed laser deposition (PLD) technique.The transmittance, current-voltage characteristics, retention characteristics, fatigue resistance and conduction mechanism of the devices are studied.The films were observed to be amorphous by X-ray diffraction (XRD).The average transmittance of the device in the visible range is 75 by UV spectrophotometer.The resistance ratio of high resistance HRS and low resistance LRS is 6, and the effective switch can be operated more than 250 times.After testing for 5 脳 10 ~ 4 s, the holding characteristics of high and low resistance state are still stable.By fitting the high and low resistance states of the devices, it is shown that the main conduction mechanism is the space charge-limited current (SCLC).The main reason is that the trapping and releasing of electrons affect the change of conducting electrons, which makes the current change.The transparent resistive memory with 偽 -IGZO / 偽 -IGZO structure was fabricated by magnetron sputtering technique.The average optical transmittance of transparent resistive memory in the visible range is 91.7 (the maximum value is 98.3 and the minimum value is 81.3 / Ga _ 2O _ 3). The optical band gap of the transparent resistive memory is 5.1 EV.It is found that the different polarity of excitation voltage will affect the distribution of oxygen vacancy in the device, resulting in different directions of the resistance curve.Variable temperature test transparent resistive memory, fit to jump conductivity mechanism.The trap jump distances of high and low resistance states are 1.4nm and 0.7 nm, respectively. The activation energies of high and low resistance states are 0.23 EV and 0.15 EV, respectively.Ag/In-Ga-Zn-O/Pt resistive memory based on In-Ga-Zn-O thin film as intermediate dielectric layer.It is found that the device exhibits self-rectifying property in low resistance state.The test temperature range is 303K-393K, and the self-rectifying property of the device remains stable.Using Cu-Ti and Ag as the upper electrodes, the self-rectifying property becomes more and more obvious with the increase of the work function of the electrode.The electrode size of the device affects the resistance.The high resistance state accords with the space charge limiting current mechanism, and the low resistance state accords with the Schottky emission mechanism. The Schottky barrier height is 0.32 EV and the dynamic dielectric constant 蔚 r is 7.9.At the same time, the Schottky barrier between the upper electrode and the In-Ga-Zn-O interface is considered to be the main reason for the self-rectifying characteristics.
【學(xué)位授予單位】：河北大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TP333;TB383.2

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本文編號：1704055