Ta_2O_5绝缘层厚度对ZnO基薄膜晶体管器件性能的影响(英文)  

Effect of Ta_2O_5 Thickness on The Performances of ZnO-based Thin Film Transistors

作　　者：周帆[1] 张良[1] 李俊[1] 张小文[1] 林华平[1] 俞东斌[1] 蒋雪茵[1,2] 张志林[1,2] 

机构地区：[1]上海大学材料科学与工程学院,上海200072 [2]上海大学新型显示技术及应用集成教育部重点实验室,上海200072

出　　处：《发光学报》2011年第2期188-193,共6页Chinese Journal of Luminescence

基　　金：supported by the National Natural Science Foundation of China(60777018,60776040);"863"project(2008AA03A336)~~

摘　　要：报道了不同厚度Ta2O5栅绝缘层对氧化锌薄膜晶体管器件性能的影响。在室温下用射频磁控溅射分别制备了100,85,60,40 nm厚度的Ta2O5薄膜作为绝缘层的一组底栅氧化锌薄膜晶体管器件。从实验结果可以得出如下结论:随着Ta2O5栅绝缘层厚度的增加,相应器件的场效应迁移率下降,其数值分别是50.5,59.3,63.8,71.2 cm2/V.s,对应100,85,60,40 nm厚度的绝缘层。从原子力显微图像可以看到,Ta2O5薄膜表面粗糙度随着薄膜厚度的减小而降低,这是场效应迁移率得以提高的主要原因。而100,85,60,40 nm不同厚度的绝缘层相应器件的开关电流比分别是1.2×105,4.8×105,3.2×104,7.2×103,其阈值电压分别为1.9,1.5,1.2,0.9 V。从各项性能综合考虑,85 nm厚度的Ta2O5栅绝缘层所制备的薄膜晶体管器件具有最佳性能。Bottom-gate ZnO thin-fibn transistors （ZnO-TFTs） were fabricated with Ta2 05 film as the insulator. Ta2O5 film was grown by the radio-frequency magnetron sputtering at room temperature. The thickness of the Ta2O5 layers were 100,85,60,40 nm separately. The effect of the thickness on the performance of the ZnO-TFTs was studied. With the thickness of the insulator decreased from 100,85,60 nm to 40 nm, the field effect mobility increased from 50.5, 59.3, 63.8 to 71.2 cm2/V · s. The surface morphology of the Ta205 films were checked by the atomic force microscope,which showed that the root mean square （RMS） of the Ta205 films roughness decreases with decreasing the insulator thickness. The Ion/Ioff ratio and the threshold voltage are changed with the insulator thickness.

关 键 词：TA2O5 绝缘层 氧化性薄膜晶体管 磁控溅射 表面形貌 

分 类 号：O472.4[理学—半导体物理]