为改善有机半导体器件的界面性能, 在氮化硅层上旋涂聚甲基丙烯酸甲酯(PMMA)构成复合绝缘层。首先, 利用原子力显微镜研究了不同浓度的PMMA复合绝缘层的表面形貌及粗糙度。接着, 蒸镀六联苯(p-6P)、酞菁铜和金电极, 构成有机的金属-绝缘层-半导体(MIS)器件。最后, 研究了MIS器件的回滞效应及电性能。实验结果表明, 复合绝缘层的粗糙度为单绝缘层的1/5, 大约1.4 nm。复合绝缘层上的p-6P薄膜随着PMMA浓度增加形成更大更有序的畴, 但单绝缘层上薄膜呈无序颗粒状。复合绝缘层的有机MIS器件几乎没有回滞现象, 但单绝缘层的器件最大回滞电压约为12.8 V, 界面陷阱电荷密度约为1.16×1012 cm-2。复合绝缘层有机薄膜晶体管的迁移率为1.22×10-2 cm2/(V·s), 比单绝缘层提高了60%, 饱和电流提高了345%。基于复合绝缘层的MIS器件具有更好的界面性能和电性能, 可应用到有机显示领域。

In order to improve the interfacial properties of organic semiconductor devices, polymethyl methacrylate(PMMA) was spin-coated on the silicon nitride insulation layers to fabricate a compound insulation layers. First, the surface topography and roughness of composite insulation layers with different PMMA concentration were investigated by atomic force microscope. Then, the organic metal-insulation-semiconductor(MIS) devices were fabricated by vacuum evaporating of para-hexaphenyl(p-6P), phthalocyanine copper and the gold material electrodes, respectively. Finally, the hysteresis effect and electrical properties of MIS devices were studied. The experimental results show that the roughness of the compound insulation layers was lower than 1/5 of the single insulating layers and was about 1.4 nm. The p-6P films can form the larger and more ordered domains on the compound insulation layers with the increase of PMMA concentration, but it is formed spherical islands on the single insulating layers. The organic MIS devices of the compound insulation layers have almost no hysteresis, but the devices of single insulation layers have the largest hysteresis voltage of about 12.8 V and its internal trap charge density is about 1.16×1012 cm-2. The mobility of MIS devices with the compound insulation layers is 1.22×10-2 cm2/(V·s), which is 60% higher than that of MIS devices of the single insulation layers. The saturation currents are increased by 345%. The MIS devices based on the compound insulation layers have better interface performance and electrical performance which can be applied to the field of organic display.