Matsushita Electric Industrial Co., Ltd.

Mamoru Furuta

Yutaka Miyata

Tetsuya Kawamura

Tatsuo Yoshioka

Shigeki Maegawa

Hiroshi Tsutsu

Koji Soma

Hiroshi Sano

Akiko Michibayashi

A first insulation film is formed as a gate insulation film of a thin film transistor, and a gate electrode is formed on the gate insulation film. Then, dopant is implanted to form source and drain regions. A second insulation film having refractive index n and film thickness d is formed to cover the first insulation film and gate electrode as an interlayer insulation film. After forming the second insulation film, laser with wavelength &lgr; is applied to activate the dopant. The film thicknesses d and d of the first and second insulation films satisfy conditions against the laser wavelength &lgr; for forming a reflection protective film at regions where activation is necessary. At the same time, the film thicknesses d and d are set in a way that the interlayer insulation film on the gate electrode forms a reflective film. This reduces the thermal damage to the gate electrode from the laser during dopant activation.

Thin film transistor manufacturing method and thin film transistor

A first insulation film is formed as a gate insulation film of a thin film transistor, and a gate electrode is formed on the gate insulation film. Then, dopant is implanted to form source and drain regions. A second insulation film having refractive index n1 and film thickness d2 is formed to cover the first insulation film and gate electrode as an interlayer insulation film. After forming the second insulation film, laser with wavelength &lgr; is applied to activate the dopant. The film thicknesses d1 and d2 of the first and second insulation films satisfy conditions against the laser wavelength &lgr; for forming a reflection protective film at regions where activation is necessary. At the same time, the film thicknesses d1 and d2 are set in a way that the interlayer insulation film on the gate electrode forms a reflective film. This reduces the thermal damage to the gate electrode from the laser during dopant activation.

With a conventional thin film transistor comprising a plurality of series-connected thin film transistors each having a plurality of LDD structures, leakage current can be decreased to a large effect but the area of an element can hardly be reduced. By connecting gate electrodes (15) of a plurality of thin film transistors only with an implanted region (13b) which is formed by implanting an impurity at a low concentration into a semiconductor thin film employed as an active layer, both reduction in element size and decrease in leakage current can be realized.

Thin film transistor, manufacturing method therefor and liquid crystal

A method for forming a polycrystalline semiconductor thin film according to the present invention includes the steps of: forming a semiconductor thin film partially containing microcrystals serving as crystal nuclei for polycrystallization on an insulating substrate; and polycrystallizing the semiconductor thin film by laser annealing.

Method for forming polycrystalline thin film and method for fabricating

A liquid crystal display apparatus includes: a liquid crystal layer; a first substrate and a second substrate interposing the liquid crystal layer therebetween; a pixel electrode and a counter electrode respectively provided on opposing faces of the first substrate and the second substrate for applying a voltage to the liquid crystal layer; and a thin-film transistor provided on the first substrate and electrically connected to the pixel electrode, the thin-film transistor including a semiconductor layer having a source region and a drain region, wherein the pixel electrode is divided into a first sub-pixel electrode and a second sub-pixel electrode; parts of the first and second sub-pixel electrodes are overlapped via an insulating layer with each other; and at least one of the first and second sub-pixel electrodes is made of the same transparent material as a material for the semiconductor layer.

Liquid crystal display apparatus including the same transparent material

A laser annealing method for a semiconductor thin film for irradiating the semiconductor thin film with a laser beam having a section whose outline includes a straight-line portion, so as to change the crystallinity of the semiconductor thin film is provided, wherein the semiconductor thin film is overlap-irradiated with the laser beam while the laser beam is shifted in a direction different from a direction along the straight-line portion. A thin film semiconductor device fabricated by use of the laser annealing method is also provided.

Laser annealing method for a semiconductor thin film

The present invention relates to a thinfilm transistor array designed to drive an active-matrix type liquid-crystal panel to be incorporated in a liquid-crystal display device, and is to offer a thinfilm transistor array solving the conventional problems of disconnections possible between the display electrodes and the drain electrodes and short-circuits possible between the display electrodes and the data wiring. By these, high-quality images can be displayed with a high reliability can be obtained together with an improved fabrication process thereof. In order to accomplish these objectives of the invention, the display electrodes of said thinfilm transistor array are disposed between the gate insulation layer and the inter-insulation layer, and the display electrodes are connected to the drain electrodes by means of a data wiring disposed through contact holes provided through the inter-insulation layer. Furthermore, the possibility of short-circuits can be minimized by insulating and isolating the display electrodes from the data wiring by means of inter-insulation layers, so that the distance between the data wiring and the display electrode can minimized and a remarkable improvement of the displayed image quality can be obtained.

Liquid-crystal display top gate thin film transistor with particular

In a method of manufacturing a thin film transistor, when impurity ions are introduced in a channel region between source and drain regions in a semiconductor layer, an insulator layer is first formed on the semiconductor layer. Then, impurity ions generated on high frequency discharge are introduced through the insulator layer into the semiconductor layer under a specified acceleration voltage. Then, the introduction depth of impurities and the amount of the impurities to be introduced in the channel region can be controlled or the threshold voltage of the thin film transistor can be controlled. This method can be applied to a large substrate.

Method of manufacturing thin film transistor

A laser beam is irradiated and scanned on a substrate of a liquid crystal display device of an active matrix type. Pairs of electrons and holes caused by the known internal photoelectric effect are produced by irradiation of the laser beam to electrical conductive thin films including silicon layered on the substrate, and pass through a defective part of short circuit in an intersection of the plural electrical conductive thin films, and thereby a current flowing through the intersection increases and a position of the defect determined on the basis of the scanning position of the laser beam and the increase of the current.

Defect detection and defect removal apparatus of thin film electronic

An active matrix substrate includes a transparent substrate, pairs each having an n-type thin-film transistor and a p-type thin-film transistor formed on the transparent substrate, gate bus lines and source bus lines connected to the n-type and p-type transistors for controlling the n-type and p-type transistors, and pixel-corresponding electrodes controlled by the transistor pairs respectively. Drains of an n-type transistor and a p-type transistor in each of the pairs are connected to each other via a related pixel corresponding electrode. First pulses are applied to gates of the n-type transistors. Second pulses are applied to gates of the p-type transistors. There is provided a difference in phase between the first pulses and the second pulses.

Growing community of inventors

Hirakata, Japan

Mamoru Furuta