A multi-element amorphous oxide semiconductor thin film and a thin film transistor thereof

Abstract

The invention discloses a multicomponent amorphous oxide semiconductor thin film and a thin film transistor, wherein the amorphous oxide semiconductor comprises at least four metal elements and an oxygen element, has an amorphous structure, a band gap of 3.3 to 4.5 eV at room temperature, a thin film thickness of 10 to 100 nm, and a visible light transmittance of more than 94%. The metal element is preferably Zn, In, Sn, Ga, Cu, Ge, Cd, Ag, Au, Pb, Bi, Sb. The multicomponent amorphous oxide semiconductor thin films can be prepared by magnetron sputtering. Thin film transistors (TFTs) fabricated with this channel layer have remarkable field effect characteristics. The switching current ratio is on the order of 107, and the field effect mobility can reach 30-50cm2 / Vs or even higher.

Description

technical field [0001] The invention relates to an amorphous oxide semiconductor thin film, in particular to a multi-component amorphous oxide semiconductor thin film and a thin film transistor. Background technique [0002] Thin film transistor (TFT) is one of the core technologies in the field of microelectronics, especially display engineering. Regardless of the active matrix liquid crystal display (AMLCD), which is absolutely dominant in the current advanced display market, or the AMOLED (active matrix organic light-emitting diode display), which represents the future trend of flexible display, TFT devices occupy a large part of the pixel drive unit. key position. In addition, TFT devices have been widely researched and applied in biosensing, ultraviolet search and other fields. Therefore, it is of great significance to research and develop TFT devices. The most important component of TFT is its channel layer material, and the research on TFT also focuses on the resea...

AI Technical Summary

Problems solved by technology

[0003] At present, the channel layer material of TFT in industrial production is mainly amorphous silicon ( a -Si) and low temperature polysilicon (LTPS), but a -Si TFT has low mobility (~2 cm 2 / Vs), it is difficult to drive displays larger than 90 inches, and based on polysilicon ( p -Si) technology TFT although high mobility (~100 cm 2 / Vs), but the uniformity of the device is poor, the electrical performance is unstable, and the production cost is high, which limits its application.

At the same time, Si is a semiconductor with an indirect band gap and narrow band gap. It is opaque in the visible light region, and the pixel aperture ratio cannot reach 100%. In order to obtain sufficient brightness, it is necessary to increase the light intensity of the light source, thereby increasing the power.

In addition, the channel layer of Si-based semiconductor material has strong photosensitivity, and a mask plate is required, which also seriously affects the aperture ratio.

These shortcomings restrict the development of Si-based TFTs

[0004] In addition, organic semiconductor thin film transistors (OTFTs) have also been studied more, but the stability of OTFTs is not high, and the mobility is relatively low (~1 cm 2 / Vs), which is a big limitation for its practical application