【摘要】：有機薄膜晶體管近年來在研究中得到廣泛的關(guān)注與發(fā)展,擁有制備簡單、成本低、可溶液法制備、柔性可彎曲等諸多優(yōu)點,并且隨著有機材料種類的增多以及性能的提高,其在性能方面已經(jīng)可以與傳統(tǒng)的多晶硅晶體管不相上下。有機薄膜晶體管在智能卡、電子標簽、傳感器,尤其是在顯示領(lǐng)域的應用具有很大的應用前景和發(fā)展?jié)摿�。因此對其進行深入的研究是十分值得的。本文基于一種新型的高分子環(huán)氧樹脂類材料作為柵極絕緣層,研究了源漏電極對有機薄膜晶體管性能的影響。首先介紹了本文所基于的新型絕緣材料的組成,然后利用了MIM(金屬-絕緣層-金屬)的結(jié)構(gòu)測試了這種聚合物材料的介電常數(shù),測得其相對介電常數(shù)為4。隨后針對絕緣材料中感光劑PAG290的配比濃度、烘烤和曝光時間以及單層和雙層絕緣層結(jié)構(gòu)對這種材料的的絕緣特性進行了優(yōu)化。在感光劑按重百分比所占比重為2%,在190℃的溫度下烘烤1小時,用波長為365nm,曝光功率為20 W/cm2曝光100秒時,該絕緣材料所表現(xiàn)出的漏電特性最佳,并且采用雙層結(jié)構(gòu)時,單位電場強度下的漏電特性最佳。其次,本文采用金(Au)作為源極和漏極的材料,并基于新型絕緣材料,通過實驗研究對比了通過剝離法和濕刻法制備源極和漏極時對有機薄膜晶體管的性能產(chǎn)生的影響。當采用剝離法時,器件所能達到的最優(yōu)遷移率為0.13 cm2/Vs,開關(guān)比為9.35×104,閾值電壓為-6.17V;采用濕刻法時,器件所能達到的最優(yōu)遷移率為0.21 cm2/Vs,開關(guān)比為2.12×105,閾值電壓為-2.35V。造成這種差距的主要原因是兩種不同工藝所制備出的源漏電極與半導體層接觸的不同而引起的接觸電阻的差異,接觸電阻值相差最大時約為1.5個數(shù)量級。不過在器件性能上,濕刻法還是優(yōu)于剝離法,所以介紹了一種新型的剝離技術(shù),即雙層光刻膠剝離技術(shù),它可以很好的彌補單層光刻膠剝離法所造成的電極與有源層產(chǎn)生不良接觸的現(xiàn)象。最后,本文介紹了在實驗過程中所發(fā)現(xiàn)的在采用金作為源漏電極材料并通過濕刻法來制備時產(chǎn)生的問題,即溝道長度在30μm以下時,器件的遲滯現(xiàn)象較為明顯,并且隨著溝道長度的減小,該現(xiàn)象更加明顯。這主要是由于金是一種高功函數(shù)材料,直接在本文所基于的新型絕緣材料上進行蒸鍍,會導致有部分金進入到絕緣層中,造成無法刻蝕干凈,使得溝道中有刻蝕殘留,因此引發(fā)遲滯現(xiàn)象。隨后通過實驗換用了銀(Ag)這種功函數(shù)相對較低的材料作為源極和漏極,發(fā)現(xiàn)遲滯現(xiàn)象得到緩解。并且通過銀加金這種混合材料,利用銀充當緩沖層以阻止金進入絕緣層中,再在此之上蒸鍍金作為源漏電極,也可以很好的解決這種遲滯現(xiàn)象。
[Abstract]:In recent years, organic thin film transistors have been widely concerned and developed in recent years. They have many advantages, such as simple preparation, low cost, solution preparation, flexible bending and so on. And with the increase of organic materials and the improvement of their properties, the organic thin film transistors have many advantages. Its performance has been comparable to that of conventional polysilicon transistors. The application of organic thin film transistor in smart card, tag, sensor, especially in display field has great application prospect and development potential. Therefore, the in-depth study of it is worth it. In this paper, the influence of source and drain electrode on the performance of organic thin film transistor is studied based on a novel polymer epoxy resin as gate insulator. Firstly, the composition of the new insulating material based on this paper is introduced. Then the dielectric constant of the polymer material is measured by using the structure of MIM (Metal-insulating layer-Metal), and the relative dielectric constant of the polymer material is measured to be 4. The insulation characteristics of the insulating material were optimized according to the ratio concentration of PAG290, the baking and exposure time, and the single layer and double layer insulation structure. When the proportion of photosensitizer by weight is 2%, baking at 190 鈩，

本文編號：2436201