Fabrication of 120-nm-channel-length ferroelectric-gate thin-film transistor by nanoimprint lithography

Abstract

Nanoimprint lithography (NIL) is one of the most promising device fabrication techniques because it has a high resolution and moderate fabrication cost. Oxide-based thin-film transistors (TFTs) with various physical properties have the potential to outperform Si-based large-scale integration (LSI) devices. In this study, we focus on the miniaturization of oxide-based TFTs by NIL. A ferroelectric-gate thin-film transistor (FGT) was prepared by incorporating a chemical-solution-deposition (CSD)-processed indium tin oxide channel, a Pb(Zr,Ti)O3 (PZT) gate insulator, and sputtered Pt electrodes. The Pt source–drain electrodes and ITO channel were patterned by the NIL process. The results show that we successfully fabricated an FGT with a channel length of 120 nm by NIL. The 120 nm channel length was confirmed by scanning electron microscopy (SEM). The fabricated NIL-FGT showed typical n-channel transistor characteristics. The obtained ON/OFF current ratio, threshold voltage, subthreshold voltage, and field-effect mobility were 103, 0.5 V, 1.0 V/decade, and 0.1–0.2 cm2·V−1·s−1, respectively.