Semiconductor Energy Laboratory Co., Ltd.

Yasushi Ogata

Shunpei Yamazaki

Jun Koyama

Hisashi Ohtani

Mitsuaki Osame

Satoshi Teramoto

Masahiko Hayakawa

Toshiji Hamatani

Akiharu Miyanaga

Toru Mitsuki

Yoshiharu Hirakata

Takeshi Nishi

Yutaka Shionoiri

Hisahi Ohtani

A metal interconnection is located in the same layer as a source line and connected to the drain of a thin-film transistor. An interlayer insulating film is constituted of at least lower and upper insulating layers and formed between a conductive coating and the source line. According to one aspect of the invention, an auxiliary capacitor is formed by the metal interconnection and the conductive coating serving as both electrodes and at least the lower insulating layer serving as a dielectric. The auxiliary capacitor is formed in a region of the interlayer insulating film in which the upper insulating layer has been removed by etching.

Active matrix liquid crystal display device

A first insulating thin film having a large dielectric constant such as a silicon nitride film is formed so as to cover a source line and a metal wiring that is in the same layer as the source line. A second insulating film that is high in flatness is formed on the first insulating film. An opening is formed in the second insulating film by etching the second insulating film, to selectively expose the first insulating film. A conductive film to serve as a light-interruptive film is formed on the second insulating film and in the opening, whereby an auxiliary capacitor of the pixel is formed between the conductive film and the metal wiring with the first insulating film serving as a dielectric.

Active matrix liquid crystal display device with overlapping conductive film and pixel electrode

A wiring line is electrically connected in parallel to an auxiliary wiring line via a plurality of contact holes. The contact holes are formed through an insulating film and arranged in vertical direction to the wiring line. Since the auxiliary wiring line is formed in the same layer as an electrode that constitutes a TFT, the electric resistance of the wiring line can be reduced effectively without increasing the number of manufacturing steps.

Semiconductor device and manufacturing method thereof

After an amorphous semiconductor thin film is crystallized by utilizing a catalyst element, the catalyst element is removed by performing a heat treatment in an atmosphere containing a halogen element. A resulting crystalline semiconductor thin film exhibits {110} orientation. Since individual crystal grains have approximately equal orientation, the crystalline semiconductor thin film has substantially no grain boundaries and has such crystallinity as to be considered a single crystal or considered so substantially.

Semiconductor thin film and semiconductor device

A wiring line to which a high-frequency signal is applied is electrically connected in parallel to an auxiliary wiring line via a plurality of contact holes. The contact holes are formed through an interlayer insulating film and arranged in vertical direction to the wiring line. Since the auxiliary wiring line is formed in the same layer as an electrode that constitutes a TFT, the electric resistance of the wiring line can be reduced effectively and waveform rounding of an applied high-frequency signal can be reduced without increasing the number of manufacturing steps.

Active matrix display device having wiring layers which are connected over multiple contact parts

A first insulating thin film having a large dielectric constant such as a silicon nitride film is formed so as to cover a source line and a metal wiring that is in the same layer as the source line. A second insulating film that is high in flatness is formed on the first insulating film. An opening is formed in the second insulating film by etching the second insulating film, to selectively expose the first insulating film. A conductive film to serve as a light-interruptive film is formed on the second insulating film and in the opening, whereby an auxiliary capacitor of the pixel is formed between the conductive film and the metal wiring with first the insulating film serving as a dielectric. The effective aperture ratio can be increased by forming the auxiliary capacitor in a selected region where the influences of alignment disorder of liquid crystal molecules, i.e., disclination, are large.

Semiconductor device including capacitor line parallel to source line

An conductive coating serves as a light shield film and is kept at a give voltage. A metal interconnection is located in the same layer as a source line and connected to the drain of a thin-film transistor. An interlayer insulating film is constituted of at least lower and upper insulating layers and formed between the conductive coating and the source line. According to one aspect of the invention, an auxiliary capacitor is formed by the metal interconnection and the conductive coating serving as both electrodes and at least the lower insulating layer film serving as a dielectric. The auxiliary capacitor is formed in a region of the interlayer insulating film in which the upper insulating layer has been removed by etching. According to another aspect of the invention, the conductive coating has a portion that is in contact with the lower insulating layer in a region where the conductive coating coextends with the metal interconnection.

Semiconductor device having thin film transistor with particular drain electrode structure

After an amorphous semiconductor thin film is crystallized by utilizing a catalyst element, the catalyst element is removed by performing a heat treatment in an atmosphere containing a halogen element. A resulting crystalline semiconductor thin film exhibits {} orientation. Since individual crystal grains have approximately equal orientation, the crystalline semiconductor thin film has substantially no grain boundaries and has such crystallinity as to be considered a single crystal or considered so substantially.

An conductive coating serves as a light shield film and is kept at a given voltage. A metal interconnection is located in the same layer as a source line and connected to the drain of a thin-film transistor. An interlayer insulating film is constituted of at least lower and upper insulating layers and formed between the conductive coating and the source line. According to one aspect of the invention, an auxiliary capacitor is formed by the metal interconnection and the conductive coating serving as both electrodes and at least the lower insulating layer film serving as a dielectric. The auxiliary capacitor is formed in a region of the interlayer insulating film in which the upper insulating layer has been removed by etching. According to another aspect of the invention, the conductive coating has a portion that is in contact with the lower insulating layer in a region where the conductive coating coextends with the metal interconnection.

Active matrix liquid crystal with capacitor below disclination region

To provide a constitution capable of reducing production cost in a semiconductor device for display of a type integrally formed with a drive circuit with a digital signal as an input signal and a pixel matrix unit, a signal dividing circuit is formed on a substrate where drive circuits and a pixel matrix unit are to be formed simultaneously with the drive circuits and the pixel matrix unit in view of fabrication steps by which fabrication steps of the signal dividing circuit per se and steps required for connecting the signal dividing circuit to wirings on the substrate can be dispensed with without adding further steps.

Signal dividing circuit and semiconductor device

Nickel is selectively held in contact with a particular region of an amorphous silicon film. Crystal growth parallel with a substrate is effected by performing a heat treatment. A thermal oxidation film is formed on the silicon film by performing a heat treatment in an oxidizing atmosphere containing a halogen element. During this step, in the silicon film, impurities included such as oxygen or chlorine, are segregated with extending along the crystal growth, the crystallinity is improved, and the gettering of nickel element proceeds. A thin-film transistor is formed so that the direction connecting source and drain regions coincides with the above crystal growth direction. As a result, a TFT having superior characteristics such as a mobility larger than 200 cm/Vs and an S value smaller than 100 mV/dec. can be obtained.

Semiconductor device and its manufacturing method

There is disclosed a method of fabricating a thin-film transistor having excellent characteristics. Nickel element is held in contact with selected regions of an amorphous silicon film. Then, thermal processing is performed to crystallize the amorphous film. Subsequently, thermal processing is carried out in an oxidizing ambient containing a halogen element to form a thermal oxide film. At this time, the crystallinity is improved. Also, gettering of the nickel element proceeds. This crystalline silicon film consists of crystals grown radially from a number of points. Consequently, the thin-film transistor having excellent characteristics can be obtained.

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Kanagawa, Japan

Yasushi Ogata