Oxide insulator film and thin-film transistor

Abstract

An oxide insulator film has a component of MxAlyZrzOdelta, wherein M is an element Sc or Y, 0.01<=x<=0.5, 0.3<=z<0.99, x+y+z=1, 0<delta<=2, and the thickness is 2-1000 nm. The oxide insulator film isprepared according to a vacuum method or a solution method and is used as an insulating layer of the thin-film transistor. The thin-film transistor is provided with a gate electrode, a channel layer,an insulating layer between the gate electrode and the channel layer, a source electrode and a drain electrode, wherein the source electrode and the drain electrode are connected with two ends of thechannel layer. The insulating layer is the oxide insulator film. The oxide insulator film has relatively large forbidden band width and is not sensitive to water, oxygen and carbon dioxide in air. Lowsurface roughness is realized. Low interface carrier trap density with an oxide semiconductor contact interface is realized. Therefore the thin-film transistor with the oxide insulator film as the insulator has advantages of high carrier mobility and stable electric performance.

Description

technical field [0001] The invention relates to the technical field of semiconductors, in particular to an oxide insulator thin film and a thin film transistor. Background technique [0002] In recent years, oxide thin-film transistors (TFTs) have attracted extensive attention and research because of their potential applications in flat panel displays, electronic labels, and sensors. Since the TFT device is a thin-film structure, the dielectric constant, crystallinity, density, bandgap width and thickness of the insulating layer have an important impact on the electrical properties of the transistor. At present, a large part of oxide TFT devices use thermally oxidized SiO 2 as an insulating layer, but SiO 2 The relative dielectric constant of the device is low (~4), and the device often needs a higher driving voltage in order to have a higher output current to meet the driving requirements. In many applications, for energy saving and safety considerations, the general requ...

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Problems solved by technology

Al 2 o 3 Although it has a high relative permittivity (~9) and bandgap width (7.3-7.8eV), and can still maintain an amorphous phase at a high annealing temperature, due to the small ionic radius of Al (0.053nm ), and the binding energy with oxygen is small (511kj / mol), which is prone to diffusion, especially the diffusion of Al in the device prepared by the solution method is relatively serious, which is detrimental to the electrical properties of the oxide semiconductor device

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