Extraction Method for Equivalent Oxide Thickness of a Thin High-κ Gate Insulator and Estimation of Field-Effect Mobility in Amorphous Oxide Semiconductor Nano-Sheet Junctionless Transistors

In this work, we have proposed an extraction method for equivalent oxide thickness (EOT) of a thin high-dielectric-constant (
$\kappa $
) gate insulator (GI) through direct capacitance–voltage (
${C}$
–
${V}$
) measurements in amorphous indium tungsten oxide (a-IWO) nano-sheet (NS) junctionless (JL) transistors (a-IWO NS-JLTs). Without additional metal/insulator/Si-substrate (MIS)
${C}$
–
${V}$
measurements, the proposed extraction method can directly extract EOT (or equivalent
$\kappa $
values) of a thin HfO
₂
GI at different ON-state gate voltages (
${V}_{G}$
) in a-IWO NS-JLTs. Results of
${C}$
–
${V}$
measurements show that the extracted EOT varies with ON-state
${V}_{G}$
owing to the gate-controllable conductance of the amorphous oxide semiconductor (AOS) NS channel. Finally, the extracted EOT can be used to estimate the field-effect mobility (
$\mu _{\text{FE}}$
) of a-IWO NS-JLTs at different ON-state
${V}_{G}$
.