An Analytical Frequency-Dependent Capacitance-Voltage Model for Metal Oxide Thin-Film Transistors

• Published in: IEEE transactions on electron devices Vol. 69; no. 1; pp. 141 - 146
• Main Authors: Xiang, Kai, Li, Hao-Yang, Li, Fei-Fan, Xu, Hua, Zhou, Lei, Xu, Miao, Wang, Lei, Wu, Wei-Jing, Peng, Jun-Biao
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.01.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Capacitance; Capacitance–voltage (<italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">C – <italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">V ); Electric potential; Electron traps; Equivalent circuits; Frequency analysis; Logic gates; metal oxide thin-film transistors (TFTs); Metal oxides; Semiconductor devices; Thin film transistors; Time-varying systems; Transistors; Transmission line measurements; transmission line method (TLM); Transmission lines; trapped electrons effect; Voltage
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2021.3124201

Based on the static capacitance-voltage (<inline-formula> <tex-math notation="LaTeX">{C}-{V} </tex-math></inline-formula>) model, a new analytical frequency-dependent <inline-formula> <tex-math notation="LaTeX">{C}-{V} </tex-math></inline-formula> model of thin-film transistors (TFTs) is derived from a modified transmission line method (TLM), which is built by embedding an equivalent circuit corresponding to the trapped electrons effect into the traditional TLM. The proposed model is well verified by the measured <inline-formula> <tex-math notation="LaTeX">{C}-{V} </tex-math></inline-formula> characteristics of bottom-gated indium-zinc-oxide (IZO) TFTs with <inline-formula> <tex-math notation="LaTeX">{W} / {L} =100 \boldsymbol {\mu }{\text {m}} /10 \boldsymbol {\mu }\text {m} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">{W} / {L} =100 \boldsymbol {\mu }\text {m} /40 \boldsymbol {\mu }\text {m} </tex-math></inline-formula>, where frequencies vary from 1 kHz to 1 MHz. The cutoff frequency of metal oxide TFTs is furthermore analyzed based on the proposed model compared with the traditional TLM.