Enhancing the Carrier Mobility and Bias Stability in Metal-Oxide Thin Film Transistors with Bilayer InSnO/a-InGaZnO Heterojunction Structure

Xiaoming Huang; Chen Chen; Fei Sun; Xinlei Chen; Weizong Xu; Lin Li

doi:10.3390/mi15040512

Enhancing the Carrier Mobility and Bias Stability in Metal-Oxide Thin Film Transistors with Bilayer InSnO/a-InGaZnO Heterojunction Structure

Micromachines (Basel). 2024 Apr 11;15(4):512. doi: 10.3390/mi15040512.

Authors

Xiaoming Huang¹, Chen Chen¹, Fei Sun¹, Xinlei Chen¹, Weizong Xu², Lin Li³

Affiliations

¹ College of Integrated Circuit Science and Engineering, Nanjing University of Posts and Telecommunications, Nanjing 210023, China.
² National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093, China.
³ Key Laboratory of Laser Technology and Optoelectronic Functional Materials of Hainan Province, College of Physics and Electronic Engineering, Hainan Normal University, Haikou 571158, China.

Abstract

In this study, the electrical performance and bias stability of InSnO/a-InGaZnO (ITO/a-IGZO) heterojunction thin-film transistors (TFTs) are investigated. Compared to a-IGZO TFTs, the mobility (µ_FE) and bias stability of ITO/a-IGZO heterojunction TFTs are enhanced. The band alignment of the ITO/a-IGZO heterojunction is analyzed by using X-ray photoelectron spectroscopy (XPS). A conduction band offset (∆E_C) of 0.5 eV is observed in the ITO/a-IGZO heterojunction, resulting in electron accumulation in the formed potential well. Meanwhile, the ∆E_C of the ITO/a-IGZO heterojunction can be modulated by nitrogen doping ITO (ITON), which can affect the carrier confinement and transport properties at the ITO/a-IGZO heterojunction interface. Moreover, the carrier concentration distribution at the ITO/a-IGZO heterointerface is extracted by means of TCAD silvaco 2018 simulation, which is beneficial for enhancing the electrical performance of ITO/a-IGZO heterojunction TFTs.

Keywords: ITO/a-IGZO heterojunction TFTs; TCAD silvaco simulation; conduction band offset; electrical performance.

Abstract

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