Junctionless Structure Indium-Tin Oxide Thin-Film Transistors Enabling Enhanced Mechanical and Contact Stability.

In recent years, considerable attention has focused on high-performance and flexible crystalline metal oxide thin-film transistors (TFTs). However, achieving both high performance and flexibility in semiconductor devices is challenging due to the inherently conductive and brittle nature of crystalline metal oxide. In this study, we propose a facile way to overcome this limitation by employing a junctionless (JL) TFT structure via oxygen plasma treatment of the crystalline indium-tin oxide (ITO) films.

Enhanced Interfacial Integrity of Amorphous Oxide Thin-Film Transistors by Elemental Diffusion of Ternary Oxide Semiconductors.

Low-temperature solution-processed oxide semiconductor and dielectric films typically possess a substantial number of defects and impurities due to incomplete metal-oxygen bond formation, causing poor electrical performance and stability. Here, we exploit a facile route to improve the film quality and the interfacial property of low-temperature solution-processed oxide thin films via elemental diffusion between metallic ion-doped InO (M:InO) ternary oxide semiconductor and AlO gate dielectric layers. Particularly, it was revealed that metallic dopants such as magnesium (Mg) and hafnium (Hf) having a small ionic radius, a high Gibbs energy of oxidation, and bonding dissociation energy could successfully diffuse into the low-quality AlO gate dielectric layer and effectively reduce the structural defects and residual impurities present in the bulk and at the semiconductor/dielectric interface.

Catalytic Metal-Accelerated Crystallization of High-Performance Solution-Processed Earth-Abundant Metal Oxide Semiconductors.

As an alternative strategy for conventional high-temperature crystallization of metal oxide (MO) channel layers, the catalytic metal-accelerated crystallization (CMAC) process using a metal seed layer is demonstrated for low-temperature crystallization of solution-processed MO semiconductors. In the CMAC process, the catalytic metal layer plays the role of seed sites for initiating and accelerating the crystallization of amorphous MO films. Generally, the solution-processed crystalline-TiO (c-TiO) films required high-temperature crystallization conditions (≥500-600 °C), showing low electrical performance with a high defect density.

The Effect of Multi-Layer Stacking Sequence of TiO Active Layers on the Resistive-Switching Characteristics of Memristor Devices.

The oxygen vacancies in the TiO active layer play the key role in determining the electrical characteristics of TiO-based memristors such as resistive-switching behaviour. In this paper, we investigated the effect of a multi-layer stacking sequence of TiO active layers on the resistive-switching characteristics of memristor devices. In particular, the stacking sequence of the multi-layer TiO sub-layers, which have different oxygen contents, was varied.

Suppression of Interfacial Disorders in Solution-Processed Metal Oxide Thin-Film Transistors by Mg Doping.

The fabrication of high-performance metal oxide thin-film transistors (TFTs) using a low-temperature solution process may facilitate the realization of ultraflexible and wearable electronic devices. However, the development of highly stable oxide gate dielectrics at a low temperature has been a challenging issue since a considerable amount of residual impurities and defective bonding states is present in low-temperature-processed gate dielectrics causing a large counterclockwise hysteresis and a significant instability. Here, we report a new approach to effectively remove the residual impurities and suppress the relevant dipole disorder in a low-temperature-processed (180 °C) AlO gate dielectric layer by magnesium (Mg) doping.

Corrugated Heterojunction Metal-Oxide Thin-Film Transistors with High Electron Mobility via Vertical Interface Manipulation.

A new strategy is reported to achieve high-mobility, low-off-current, and operationally stable solution-processable metal-oxide thin-film transistors (TFTs) using a corrugated heterojunction channel structure. The corrugated heterojunction channel, having alternating thin-indium-tin-zinc-oxide (ITZO)/indium-gallium-zinc-oxide (IGZO) and thick-ITZO/IGZO film regions, enables the accumulated electron concentration to be tuned in the TFT off- and on-states via charge modulation at the vertical regions of the heterojunction. The ITZO/IGZO TFTs with optimized corrugated structure exhibit a maximum field-effect mobility >50 cm V s with an on/off current ratio of >10 and good operational stability (threshold voltage shift <1 V for a positive-gate-bias stress of 10 ks, without passivation).