Thin film transistor and producing method thereof

Abstract

Provided is a manufacturing method of a thin film transistor extremely low in a defect level which is excellent in an operation property. The method includes steps of: forming an undercoat film comprising a silicon nitride film 2 and a silicon oxide film 3 on an insulating substrate 1; forming an amorphous silicon film 10 on the undercoat film; forming an interface protecting film comprising a silicon oxide film 11 on the silicon film 10; laser-annealing the silicon film 10 by irradiating a YAG laser on the substrate on which the interface protecting film is formed; patterning the silicon film 4 after laser annealing; and forming a gate insulating film comprising a silicon oxide film 5 on the substrate after patterning wherein the undercoat film, the amorphous silicon 10, and the interface protecting film are sequentially formed in a vacuum chamber while a vacuum state is maintained.

Description

technical field [0001] The present invention relates to a thin film transistor and a method of manufacturing the same, and more specifically, to a method of manufacturing a thin film transistor using polysilicon obtained by laser annealing amorphous silicon as a semiconductor layer, such as a thin film transistor constituting each pixel of a liquid crystal display device improvement of. Background technique [0002] A so-called active matrix liquid crystal display device is formed by forming a plurality of thin film transistors in a matrix on a glass substrate. Generally, an amorphous silicon film can be produced at a lower temperature than a silicon oxide film, so thin-film transistors using an amorphous silicon film as a semiconductor layer, so-called amorphous silicon TFTs, are widely used in conventional liquid crystal display devices. (Thin Film Transistor). [0003] However, thanks to the development of laser annealing technology for locally melting and crystallizing...

AI Technical Summary

Problems solved by technology

[0016] As mentioned above, in the conventional thin film transistor, in the manufacturing process up to the formation of the gate insulating film, since the natural oxide film is formed on the surface of the amorphous silicon film 10 and the polysilicon film 4, there is a problem that makes the operation of the thin film transistor difficult. The problem of deterioration of characteristics

In addition, in the photolithography process, there is a problem that the polysilicon film is not contaminated, which deteriorates the operating characteristics as a thin film transistor.

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