物理学报2017，Vol.66Issue(23)：281-289,9.DOI:10.7498/aps.66.237101
氢化非晶硅薄膜晶体管的低频噪声特性
Low-frequency noise in hydrogenated amorphous silicon thin film transistor
摘要
Abstract
Low-frequency noise in the hydrogenated amorphous silicon thin film transistor is investigated in this paper. The drain current noise spectral density shows a 1/fγ (γ ≈ 0.92, f represents frequency) behavior which ascribes to fluctu-ations of the interfacial trapped charges due to the dynamic trapping and de-trapping of free carriers into slow oxide traps and localized traps. The normalized noise has the power law dependence on overdrive voltage, and the power law coefficient is about -1 which illustrates that the flicker noise is dominated by mobility fluctuation mechanism. By considering the contact resistance, and emission and trapping processes of carriers between localized states in the Si/SiNx interface, the variation of low frequency noise with drain current is analyzed and fitted by use of the theory of carrier number fluctuation with correlated mobility fluctuation (?N-?μ model). Furthermore, the relationship between surface band-bending and gate voltage is extracted based on subthreshold current-voltage characteristics, and thus the density of localized states is then extracted through the measurement of drain current noise power spectral density. The experimental results show an exponential localized state distribution in the band-gap while densities of two defect modes at the bottom of conduction band NT1 and NT2 are about 6.31 × 1018 and 1.26 × 1018 cm-3·eV-1, and corresponding characteristic temperatures TT1 and TT2 are about 192 and 290 K, which is similar to the reported distribution of tail states in the amorphous silicon layer. Finally, the average Hooge's parameter is extracted to estimate the quality of devices and materials.关键词
非晶硅/薄膜晶体管/低频噪声/局域态密度Key words
amorphous silicon/thin film transistor/low-frequency noise/density of localized state引用本文复制引用
刘远,何红宇,陈荣盛,李斌,恩云飞,陈义强..氢化非晶硅薄膜晶体管的低频噪声特性[J].物理学报,2017,66(23):281-289,9.基金项目
国家自然科学基金 (批准号: 61574048)、广东省科技重大专项 (批准号: 2015B090912002) 和广州市珠江科技新星专项 (批准号:201710010172) 资助的课题. Project supported by the National Natural Science Foundation of China (Grant No. 61574048), the Science and Tech-nology Research Project of Guangdong, China (Grant No. 2015B090912002), and the Pearl River S&T Nova Program of Guangzhou, China (Grant No. 201710010172). （批准号: 61574048）
