Hannstar Display Corporation

Chun-Hung Chu

Chih-Yu Peng

Chih-Lung Lin

Chian-Chih Hsiao

Chin-Mao Lin

Ta-Ko Chuang

Wei-Chuan Lin

A thin film transistor array substrate of a thin film transistor liquid crystal display (TFT-LCD) is provided. The gate dielectric layer of the TFT includes a silicon nitride layer, a dielectric layer and a silicon nitride layer, and the etching selectivity of the amorphous silicon layer over the dielectric layer is not less than about 5.0. Therefore, the dielectric layer can be an etching stop layer when doped and undoped amorphous silicon layers are etched to form source/drain stacked layers or a conductive layer is etched to form a gate on the gate dielectric layer. Hence, the dielectric layer thickness can be controlled, and thereby the capacitance of the storage capacitor can be controlled.

Thin film transistor array substrate

A method of controlling the capacitance of a thin film transistor liquid crystal display (TFT-LCD) storage capacitor is disclosed. In certain embodiments, the method includes i) forming a silicon island and a bottom electrode on the transparent substrate, the silicon island having an undoped region located on the central portion, and two doped regions respectively located on both sides, ii) forming a first silicon nitride layer on the transparent substrate, and iii) forming a stacked layer comprising a second silicon nitride layer and a conductive layer on the undoped region of the silicon island, and the first conductive layer of the stacked layer serving as a gate of a thin film transistor, wherein an etching selectivity ratio of the conductive layer over the dielectric layer is not less than about 5.0.

Method of controlling a capacitance of a thin film transistor liquid crystal display (TFT-LCD) storage capacitor

A method of controlling the capacitance of a thin film transistor liquid crystal display (TFT-LCD) storage capacitor is disclosed. In certain embodiments, the method includes i) forming an undoped amorphous silicon layer on a silicon nitride layer, ii) forming an etching mask on the undoped amorphous silicon layer, and iii) forming two doped amorphous silicon layers on portion of the undoped amorphous silicon layer and the etching mask, the two doped amorphous silicon layers being spaced apart and located on either side of the gate, wherein an etching selectivity ratio of the undpoed and doped amorphous silicon layers over the dielectric layer being not less than about 5.0.

A method of controlling the capacitance of the TFT-LCD storage capacitor is provided. The gate dielectric layer of the TFT is composed of a silicon nitride layer, a dielectric layer and a silicon nitride layer, and the etching selectivity of the amorphous silicon layer over the dielectric layer is not less than about 5.0. Therefore, the dielectric layer can be an etching stop layer when a doped and an undoped amorphous silicon layers are etched to form source/drain stacked layers or a conductive layer is etched to form a gate on the gate dielectric layer. Hence, the dielectric layer thickness can be controlled; thereby the capacitance of the storage capacitor can be controlled.

Growing community of inventors

Fengyuan, Taiwan

Chun-Hung Chu