Universal model of bias-stress-induced instability in inkjet-printed carbon nanotube networks field-effect transistors

作者：Jung Haesun; Choi Sungju; Jang Jun Tae; Yoon Jinsu; Lee Juhee; Lee Yongwoo; Rhee Jihyun; Ahn Geumho; Yu Hye Ri; Kim Dong Myong^*; Choi Sung Jin; Kim Dae Hwan^*

来源：Solid-State Electronics, 2018, 140: 80-85.

DOI：10.1016/j.sse.2017.10.022

• Carbon nanotube networks FETs
• Bias stress instability
• Interface trap
• Technology computer-aided design (TCAD) simulation

We propose a universal model for bias-stress (BS)-induced instability in the inkjet-printed carbon nanotube (CNT) networks used in field-effect transistors (FETs). By combining two experimental methods, i.e., a comparison between air and vacuum BS tests and interface trap extraction, BS instability is explained regardless of either the BS polarity or ambient condition, using a single platform constituted by four key factors: OH- adsorption/desorption followed by a change in carrier concentration, electron concentration in CNT channel corroborated with H2O/O-2 molecules in ambient, charge trapping/detrapping, and interface trap generation. Under negative BS (NBS), the negative threshold voltage shift (Delta V-T) is dominated by OH- desorption, which is followed by hole trapping in the interface and/or gate insulator. Under positive BS (PBS), the positive Delta V-T is dominated by OH- adsorption, which is followed by electron trapping in the interface and/or gate insulator. This instability is compensated by interface trap extraction; PBS instability is slightly more complicated than NBS instability. Furthermore, our model is verified using device simulation, which gives insights on how much each mechanism contributes to BS instability. Our result is potentially useful for the design of highly stable CNT-based flexible circuits in the Internet of Things wearable healthcare era.

• 出版日期2018-2