Al2 O3薄层修饰SiNx绝缘层的IGZO-TFTs器件的性能研究

摘要

Top-contact thin-film transistors( TFTs) were fabricated using SiNx as the gate insulator and InGaZnO as the channel layer. The insulator was modified by Al2 O3 layer and its effect on the performance of IGZO-TFTs was investagated. The results show that TFTs with 4-nm-thick Al2 O3 film exhibits the best electrical performance. The best performance can be attributed to the suppression of maximum density of surface states at the channel-insulator interface which is reduced by 17 . 2%contrasting to the TFTs without Al2 O3 buffer layers. The field effect mobility increases from 1. 19 to 7. 11 cm2/(V·s), and the threshold voltage decreases from 39. 70 to 25. 37 V. Under bias stress for 1 h, the threshold voltage shift decreases from 2. 19 to 1. 41 V/dec.%采用原子层沉积工艺( ALD)生长均匀致密的三氧化二铝( Al2 O3)薄层对氮化硅( SiNx )绝缘层进行修饰,研究了铟镓锌氧薄膜晶体管( IGZO-TFTs)器件的性能。当Al2 O3修饰层厚度为4 nm时,绝缘层-有源层界面的最大缺陷态密度相比于未修饰器件降低了17.2%,器件性能得到显著改善。场效应迁移率由1.19 cm2/(V·s)提高到7.11 cm2/(V·s),阈值电压由39.70 V降低到25.37 V,1 h正向偏压应力下的阈值电压漂移量由2.19 V减小到1.41 V。