Enhanced performances of ZnO-TFT by improving surface properties of channel layer
Enhanced performances of ZnO-TFT by improving surface properties of channel layer
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通过改善沟道层的表面特性增强ZnO-TFT的性能
DOI：
10.1016/j.ssc.2008.03.036
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发表时间：
2008-06-01
影响因子：
2.1
通讯作者：
Zhang, Zhi Lin
中科院分区：
文献类型：
--
作者：
Zhang, Liang;Zhang, Hao;Zhang, Zhi Lin
采用射频溅射法制备了以氧化锌为沟道层、以热生长的二氧化硅为栅介质的顶接触薄膜晶体管。研究了不同有源层厚度的氧化锌薄膜晶体管的性能，得到了最佳工艺条件。当有源层厚度从25 nm增加到70 nm时，器件的漏电流从10(-10)A增加到10(-8)A，通断比从1.2×10(7)下降到2×10(4)。原子力显微镜研究表明，随着厚度的增加，活性层表面形貌先明显改善后恶化。25 nm厚的氧化锌薄膜晶体管的表面形貌最好，场效应迁移率为5.1 cm(2)/V S，通断比为1.2×10(7)，阈值电压为20V，表明沟道层的表面性质对薄膜晶体管的性能有重要影响。(C)2008爱思唯尔有限公司。保留所有权利。
Top-contact thin film transistors with ZnO as the channel layer and thermally grown SiO2 as the gate dielectric were fabricated by using rf sputtering. The performances of ZnO-TFTs with different thicknesses of the active layer were investigated and the optimized condition was obtained. With the active layer thickness from 25 to 70 nm, the leakage current of devices increased from 10(-10) to 10(-8) A, and the on/off ratio decreased from 1.2 x 10(7) to 2 x 10(4). Atomic force microscope research indicated that with the thickness increased, the surface morphology of the active layer improved noticeably at first and then deteriorated. The 25-nm-thick ZnO TFT had the best surface morphology, and showed the best performance with a field effect mobility of 5.1 cm(2)/V S, on/off ratio of 1.2 x 10(7) and threshold voltage of 20 V. This indicates that the surface properties of the channel layer have crucial affects on the performances of ZnO-TFTs. (C) 2008 Elsevier Ltd. All rights reserved.