Hitachi, Ltd.

Hitachi Displays, Ltd.

Hironaru Yamaguchi

Kiyoshi Ogata

Takuo Tamura

Yoshinobu Kimura

Makoto Ohkura

Hironobu Abe

Yoichi Takahara

Masakazu Saitou

Toshihiko Itoga

Kazuhiko Horikoshi

Kazuo Takeda

Jun Gotoh

Masakazu Saito

Hidefumi Ibe

Michiko Takahashi

Shigeo Shimomura

Naoki Yamagami

The average film thickness of an amorphous silicon film formed on a substrate is measured. Then, the amorphous silicon film is irradiated with a laser beam to form a polysilicon film, and the grain size distribution of the polysilicon film is measured. An optimum value of energy density of laser beam irradiation is calculated on the basis of grain size values measured at two points A and B of the polysilicon film. Then, the average film thickness of an amorphous silicon film formed on a subsequent substrate is measured. A value of energy density of laser beam irradiation for the subsequent amorphous silicon film is calculated on the basis of the two average film thicknesses. Accordingly, a uniform polysilicon film of large grain sizes is formed on the whole surface of a large-size substrate to provide polysilicon TFTs in a large area.

Display device and method for manufacturing the same

An amorphous silicon film is laser irradiated a plural number of times to make the film composed of a plurality of crystal grains while suppressing the formation of protrusions at the boundaries of the adjoining grains to realize a polycrystalline silicon thin film transistor having at least partly therein the clusters of grains, or the aggregates of at least two crystal grains, with preferred orientation in the plane (111), and having high electron mobility of 200 cm/Vs or above.

Thin film transistor and method of manufacturing the same

Thin film transistor and display using the same

Analyzer/observer

An amorphous silicon film is laser irradiated a plural number of times to make the film composed of a plurality of crystal grains while suppressing the formation of protrusions at the boundaries of the adjoining grains to realize a polycrystalline silicon thin film transistor having at least partly therein the clusters of grains, or the aggregates of at least two crystal grains, with preferred orientation in the plane (111), and having high electron mobility of 200 cm /Vs or above.

Irradiation of manufacturing a thin film transistor by laser irradiation

Disclosed is a polysilicon film adapted for use in a liquid crystal display, and method of manufacturing such film. In manufacturing the film, a native oxide layer formed on a surface of an amorphous silicon film is completely removed by a hydrofluoric acid solution, followed by immersing in an H O solution to newly form an extremely thin oxide layer, prior to a crystallizing processing performed by a laser beam irradiation. The crystallizing processing forms a polysilicon film formed of crystal grains Preferentially oriented on the (111) plane in a direction parallel to the substrate surface, an average crystal grain size being not larger than 300 nm, the standard deviation of the grain sizes being not larger than 30% of the average grain size, and the standard deviation of the roughness being not larger than 10% of the average grain size.

Liquid crystal display element and method of manufacturing the same

Transistor with thin film active region having clusters of different crystal orientation

Growing community of inventors

Tokyo, Japan

Hironaru Yamaguchi