Hitachi Displays, Ltd.

Hitachi, Ltd.

Panasonic Liquid Crystal Display Co., Ltd.

Takahiro Kamo

Takuo Kaitoh

Toshihiko Itoga

Takeshi Noda

Yoshiyuki Kaneko

Yoshinobu Kimura

Kiyoshi Ogata

Takeshi Sato

Makoto Ohkura

Mikio Hongo

Kazuhiko Horikoshi

Ryoji Oritsuki

Takuo Tamura

Akio Yazaki

Miwako Nakahara

Yasushi Nakano

Toshio Miyazawa

Takeo Shiba

Hidekazu Miyake

Katsumi Matsumoto

Yasukazu Kimura

Eiji Oue

Terunori Saitou

Hideki Nakagawa

Yoshiharu Owaku

A display device includes a TFT substrate in which a plurality of first TFT elements each having an active layer of an amorphous semiconductor and a plurality of second TFT elements each having an active layer of a polycrystalline semiconductor are disposed on a surface of an insulating substrate, wherein the first TFT element and the second TFT element each have a structure with a gate electrode, a gate insulating film, and the active layer stacked in this order on the surface of the insulating substrate and a source electrode and a drain electrode both connected to the active layer via a contact layer above the active layer, and the active layer of the second TFT element has a thickness of more than 60 nm in a position where the contact layer is stacked.

Display device and manufacturing method thereof

A display device includes: a conductive layer on which gate electrodes are formed; a first insulation layer which is formed on the conductive layer; a semiconductor layer which is formed on the first insulation layer and is provided for forming semiconductor films which contain poly-crystalline silicon above the gate electrodes; and a second insulation layer which is formed on the semiconductor layer. Here, the semiconductor film includes a channel region which overlaps with the gate electrode as viewed in a plan view. In the channel region, a portion of the semiconductor film which is in contact with the second insulation layer exhibits higher impurity concentration than a portion of the semiconductor film which is in contact with the first insulation layer.

A display device having a photosensor which exhibits excellent photoelectric conversion efficiency is provided. In a display device which forms photosensors on a substrate thereof, the photosensor is formed by sequentially stacking a gate electrode, a gate insulation film and a semiconductor layer in such an order or in an opposite order from a substrate side, and electrodes are connected to both sides of the semiconductor layer respectively, the semiconductor layer is formed of a stacked body consisting of a crystalline semiconductor layer and an amorphous semiconductor layer, and the crystalline semiconductor layer is arranged on the gate insulation film side.

Display device

In crystallization of a silicon film by annealing using a linear-shaped laser beam having a width of the short axis of the beam is ununiform, the profile (intensity distribution) of the laser beam is evaluated and the results are fed back to a condition of oscillating the laser beam or an optical condition for projecting the laser beam onto the silicon film, whereby a display device comprising a high-quality crystalline silicon film is manufactured. The energy distribution of the linear-shaped laser beam is determined by a detector type CCD camera which is moved stepwise in the directions in which its long axis and short axis extend, respectively, and a value obtained by dividing an accumulated intensity E in the long axis direction obtained by accumulating the detected signal in the direction parallel to the short axis by the square root of the width W of the short axis of the above linear-shaped laser beam in each position of the long axis: E/&#x221a;{square root over ( )}(W), is determined in all the positions of a cross section of the linear-shaped laser beam to evaluate the above intensity distribution.

Manufacturing method of display device

The present invention provides a display device which forms thin film transistor circuits differing in characteristics from each other on a substrate in mixture and a fabrication method of the display device. On a glass substrate having a background layer which is formed by stacking an SiN film and an SiOfilm, a precursor film which is constituted of an a-Si layer or a fine particle crystalline p-Si layer is formed and the implantation is applied to the precursor film. Here, an acceleration voltage and a dose quantity are adjusted such that a proper quantity of dopant is dosed in the inside of the precursor film. When the precursor film is melted by laser radiation, the dopant dosed in the precursor film is activated and taken into the precursor.

Display device and fabrication method thereof

In crystallization of a silicon film by annealing with a linear-shaped laser beam having an ununiform width of the short axis of the beam, the profile (intensity distribution) of the laser beam is evaluated, and the result is fed back to an oscillating condition of the laser beam or an optical condition which projects this onto the silicon film, whereby a display device comprising a high-quality crystalline silicon film is produced. In the present invention, (1) the energy distribution of the linear-shaped laser beam is measured by a detector type CCD camera moved stepwise in the directions that its long axis and short axis extend, respectively, (2) a value obtained by dividing an accumulated intensity E in the long axis direction obtained by accumulating the detected signals in a direction parallel to the short axis by the square root of the width W of the short axis of the linear-shaped laser beam in each position in the long axis: E/&#x221a;{square root over ( )}(W), is determined in all the positions of a cross section of the linear-shaped laser beam. Since a laser power which is suitable for lateral crystal growth of the silicon film has a close correlation with E/&#x221a;{square root over ( )}(W), this value is used as an evaluation result mentioned above in the present invention.

A method of irradiating at least a part of a semiconductor film on the substrate with a CW or pseudo-CW laser beam so as to grow crystals laterally. A region over the semiconductor film having Si as a chief component is provided with a pixel region, a gate line driving circuit region and a signal line driving circuit region for driving pixels, and a terminal region where connection terminals will be formed. The region not irradiated with the CW laser beam is provided in a peripheral portion of each semiconductor device corresponding to the position where the glass substrate will be cut. Due to this means, it is possible to suppress occurrence of a failure caused by propagation of cracks when the substrate is cut.

Laser crystallization method suppressing propagation of cracks forming a display device

A semiconductor device and a method of manufacture thereof by forming an amorphous semiconductor film on the surface of an insulative substrate, and irradiating the amorphous semiconductor film with a laser beam to crystallize it to form a polycrystalline semiconductor thin film. A transistor is then formed in the polycrystalline semiconductor thin film. More specifically, a UV-ray is irradiated to the rear face of the insulative substrate or the amorphous semiconductor film to heat the amorphous semiconductor film to a melting temperature or lower. Then a laser beam at a suitable shape selection laser energy density Ec forms the crystal grains with the number of closest crystal grains of 6 most predominantly being irradiated to convert the amorphous semiconductor film into a polycrystalline semiconductor thin film. The thin film transistor formed in this structure has a high yield and is capable of high-speed operation.

Polysilicon semiconductor thin film substrate, method for producing the same, semiconductor device, and electronic device

The invention provides a method of manufacture of a display device which can achieve a reduction of the manufacturing process. In the manufacturing method, a semiconductor layer is formed over an upper surface of a substrate. An insulation film is formed over an upper surface of the semiconductor layer. Using a mask which covers a first region and exposes a second region, an implantation of impurities into the semiconductor layer is performed in the second region through the insulation film. After the mask is removed, a surface of the insulation film is etched in the first region and the second region to an extent that the insulation film in the second region remains, whereby the film thickness of the insulation film in the second region is set to be smaller than the film thickness of the insulation film in the first region.

Display device and manufacturing method of the same

In a display device including thin film transistors formed on an insulation substrate, the thin film transistor includes a semiconductor layer, a gate electrode and a gate insulation film which is interposed between the semiconductor layer and the gate electrode. The gate insulation film includes at least one layer of deposition film which is deposited by a deposition method, and the carbon concentration of the gate insulation film which is formed without interposing other deposition film deposited by a deposition method between the one deposition film and the semiconductor layer has the distribution in which the carbon concentration is smaller at a side close to the semiconductor layer than at a side remote from the semiconductor layer. Due to such a constitution, it is possible to obviate the elevation of a level of an interface of the insulation film with respect to a poly silicon layer and it is also possible to obviate an increase of fixed charges in the inside of the insulation film in the thin film transistor.

To a polycrystalline silicon layer crystallized by irradiation with laser light, a mixed gas comprised of ozone gas and H O or N O gas is fed at a processing temperature of 500&deg; C. or below, or the polycrystalline silicon layer is previously treated with a solution such as ozone water or an aqueous NH /hydrogen peroxide solution, followed by oxidation treatment with ozone, to form a silicon oxide layer with a thickness of 4 nm or more at the surface of the polycrystalline silicon layer for forming a thin-film transistor having characteristics that are less varying on a glass substrate previously not annealed.

Thin-film transistor and method of manufacturing the same

To a polycrystalline silicon layer crystallized by irradiation with laser light, a mixed gas comprised of ozone gas and H O or N O gas is fed at a processing temperature of 500&deg; C. or below, or the polycrystalline silicon layer is previously treated with a solution such as ozone water or an aqueous NH /hydrogen peroxide solution, followed by oxidation treatment with ozone, to form a silicon oxide layer of 4 nm or more thick at the surface of the polycrystalline silicon layer for forming a thin-film transistor having less variations of characteristics on an unannealed glass substrate.

Process of manufacturing a thin-film transistor

A first thin film is formed on one surface of an insulating base, and a second thin film having a thermal conductivity higher than the first thin film is formed on the first thin film. An amorphous semiconductor thin film having a higher thermal conductivity than the second thin film is formed on at least the second thin film. The amorphous semiconductor thin film is changed to a polycrystalline semiconductor thin film through laser annealing. The provision of the second thin film results in larger and uniform crystal grain diameters and less proturberances in the polycrystalline semiconductor thin film.

SEMICONDUCTOR DEVICE HAVING FIRST, SECOND AND THIRD NON-CRYSTALLINE FILMS SEQUENTIALLY FORMED ON INSULATING BASE WITH SECOND FILM HAVING THERMAL CONDUCTIVITY NOT LOWER THAN THAT OF FIRST FILM AND NOT HIGHER THAN THAT OF THIRD FILM, AND METHOD OF MANUFACTURING THE SAME

Growing community of inventors

Mobara, Japan

Takahiro Kamo