本文選題：氧化物薄膜晶體管　切入點(diǎn)：共濺射　出處：《吉林大學(xué)》2015年碩士論文

【摘要】：隨著未來顯示逐漸向高分辨率、大面積以及柔性化方向的發(fā)展，對(duì)背板技術(shù)性能要求更高。以銦鎵鋅氧化物薄膜晶體管為代表的氧化物薄膜晶體管以其場(chǎng)效應(yīng)遷移率高、透過率高、大面積均勻性好等優(yōu)點(diǎn)，得到人們廣泛關(guān)注。此外，以IGZO薄膜晶體管作為背板技術(shù)制備的顯示面板還具有功耗低的優(yōu)點(diǎn)。然而，IGZO中含有稀有元素In、Ga，不利于降低成本，因此研究不含稀有元素、且性能能與IGZO薄膜晶體管相比擬的氧化物薄膜晶體管具有重要的意義。 本文從稀有元素替代角度出發(fā)，根據(jù)IGZO薄膜中載流子傳輸機(jī)理，采用Al、Sn分別替代IGZO薄膜中的Ga、In元素。并采用與現(xiàn)代工業(yè)生產(chǎn)相兼容的磁控濺射工藝，通過三靶磁控共濺射Al2O3、ZnO和SnO2靶材的方式，制備了Al-Zn-Sn-O（AZTO）薄膜及其薄膜晶體管，并對(duì)AZTO薄膜及其薄膜晶體管的性能進(jìn)行了研究，具體工作內(nèi)容如下： 1、通過調(diào)節(jié)濺射過程中Al2O3的沉積功率，制備了在不同Al2O3沉積功率下AZTO薄膜。結(jié)果顯示，在不同Al2O3沉積功率下，所制備的AZTO薄膜都是非晶的，并且均具有較高的透過率，單層薄膜在人眼最敏感波長（550nm）處的透過率均在85%以上。 2、我們進(jìn)一步制備了在不同Al2O3沉積功率下AZTO薄膜晶體管，研究了不同Al2O3含量對(duì)器件性能的影響。結(jié)果表明，隨著Al2O3沉積功率的增加，器件的遷移率逐漸降低，閾值電壓逐漸增大，但器件的轉(zhuǎn)移特性得到了有效的改善，并且開關(guān)比顯著提高。分析得出，Al在AZTO薄膜中充當(dāng)著抑制載流子的作用，就像IGZO中的Ga一樣。當(dāng)Al2O3濺射功率為20W時(shí)，獲得了較好的器件性能。通過冷場(chǎng)發(fā)射掃描電子顯微鏡(JSM-7500F)測(cè)得，當(dāng)Al2O3濺射功率為20W時(shí)，未退火AZTO薄膜中Zn、Sn、Al、O的原子含量分別為17%、3%、2%、78%。 3、我們制備了不同有源層厚度的器件，研究了有源層厚度對(duì)器件性能的影響。結(jié)果表明，有源層厚度對(duì)器件性能的影響很大，當(dāng)厚度太薄時(shí)，載流子數(shù)量太少，遷移率過低；而當(dāng)厚度過厚時(shí)，一方面會(huì)增大載流子注入電阻，另一方面厚度過厚將會(huì)引起載流子數(shù)量過多，發(fā)生散射，結(jié)果都會(huì)使得遷移率有所下降。當(dāng)有源層厚度為45nm時(shí)，我們獲得了最優(yōu)的器件性能。 4、對(duì)上述獲得的最佳器件，我們進(jìn)一步研究了正向偏壓下器件的穩(wěn)定性。結(jié)果發(fā)現(xiàn)，在正向偏壓應(yīng)力下，器件的閾值電壓發(fā)生了正向漂移。這是由于被柵電壓吸引到溝道層與絕緣層界面處的自由載流子被界面處的負(fù)電荷陷阱俘獲，，或者是注入到絕緣層體內(nèi)，被體內(nèi)的陷阱捕獲。所以載流子數(shù)量降低，閾值電壓發(fā)生正向漂移。
[Abstract]:With the development of high resolution, large area and flexibility in the future display, the technical performance of back plate is more demanding. The field effect mobility of oxide thin film transistors represented by indium gallium zinc oxide thin film transistors is higher than that of indium gallium zinc oxide thin film transistors. The advantages of high transmittance and good uniformity in large area have attracted wide attention. In addition, the display panel fabricated with IGZO thin film transistor as backplane technology also has the advantage of low power consumption. Therefore, it is of great significance to study oxide thin film transistors which contain no rare elements and whose properties are comparable to those of IGZO thin film transistors. In this paper, based on the carrier transport mechanism of IGZO thin films, the Gain elements in IGZO thin films are replaced by Alnion Sn, and the magnetron sputtering process compatible with modern industrial production is adopted. Al-Zn-Sn-OZTOA) thin films and their thin film transistors were prepared by three-target magnetron co-sputtering of Al _ 2O _ 3ZnO and SnO2 targets. The properties of AZTO thin films and their thin film transistors were studied. The main work is as follows:. 1. By adjusting the deposition power of Al2O3 during sputtering, AZTO thin films were prepared under different Al2O3 deposition power. The results show that the AZTO films prepared under different Al2O3 deposition power are amorphous and have high transmittance. The transmittance of monolayer films is over 85% at the most sensitive wavelength of 550 nm. 2. We have prepared AZTO thin film transistors with different Al2O3 deposition power, and studied the effect of different Al2O3 content on the device performance. The results show that the mobility of the devices decreases with the increase of Al2O3 deposition power. The threshold voltage increases gradually, but the transfer characteristics of the device are improved effectively and the switching ratio is significantly improved. It is found that Al acts as a carrier suppressor in AZTO films, just like Ga in IGZO. When the sputtering power of Al2O3 is 20 W, Good device properties have been obtained by using a cold field emission scanning electron microscope (JSM-7500F). When the sputtering power of Al2O3 is 20W, the atomic content of ZnSn-Sn-Al _ 2O in unannealed AZTO thin films is 17 / 3 / 7500F, respectively. 3. The influence of the thickness of the active layer on the performance of the device is studied. The results show that the thickness of the active layer has a great effect on the performance of the device. When the thickness is too thin, the number of carriers is too small and the mobility is too low. When the thickness is too thick, on the one hand, the carrier injection resistance will increase, and on the other hand, the thickness of the carrier will lead to excessive carrier number and scattering, resulting in a decrease in mobility. When the thickness of the active layer is 45nm, We have obtained the optimal device performance. 4. For the optimum device obtained above, we further study the stability of the device under forward bias. The threshold voltage of the device is positively shifted because the free carrier attracted by the gate voltage to the interface between the channel layer and the insulating layer is captured by the negative charge trap at the interface or injected into the insulating layer. The number of carriers is reduced and the threshold voltage is positively drifted.
【學(xué)位授予單位】：吉林大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：TN321.5

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 邵宇,戴文新,王緒緒,丁正新,劉平,付賢智;鋁片表面陽極氧化鋁膜的光催化作用[J];物理化學(xué)學(xué)報(bào);2005年06期

2 靳錫聯(lián);婁世云;孔德國;李蘊(yùn)才;杜祖亮;;Mg摻雜ZnO所致的禁帶寬度增大現(xiàn)象研究[J];物理學(xué)報(bào);2006年09期

3 于桂霞;祝洪良;姚奎鴻;;二氧化錫(SnO_2)納米顆粒的水熱合成及表征[J];浙江理工大學(xué)學(xué)報(bào);2006年02期

4 馮魏良;黃培;;柔性顯示襯底的研究及進(jìn)展[J];液晶與顯示;2012年05期

本文編號(hào)：1669434