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

Based on the static capacitance-voltage (
${C}-{V}$
) model, a new analytical frequency-dependent
${C}-{V}$
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
${C}-{V}$
characteristics of bottom-gated indium-zinc–oxide (IZO) TFTs with
${W} / {L} =100 \boldsymbol {\mu }{\text {m}} /10 \boldsymbol {\mu }\text {m}$
and
${W} / {L} =100 \boldsymbol {\mu }\text {m} /40 \boldsymbol {\mu }\text {m}$
, 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.