Patents by Inventor Naoaki Yamaguchi

Naoaki Yamaguchi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5926735
    Abstract: There is disclosed a manufacturing method of highly integrated circuits with thin-film transistors (TFTs) for use as peripheral driver circuitry in active-matrix liquid crystal display (LCD) panel with a pixel array each having a charge transfer control TFT, capable of facilitating formation of contact holes otherwise being difficult in cases where an anode oxide film is formed on gate electrodes of TFTs and lead wires both of which are made of anodizable metal, such as aluminum. The method includes execution of anodization while causing a resist mask to be disposed on part of the lead wire and electrode made of aluminum, thereby partly eliminating formation of the anode oxide film on the lead wire and electrode. At a later step of fabrication, each contact is formed by use of such portion that has no anode oxide film formed thereon. This may allow aluminum to be employed as lead wires while enabling easy fabrication of contacts therefor.
    Type: Grant
    Filed: February 19, 1997
    Date of Patent: July 20, 1999
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Shunpei Yamazaki, Naoaki Yamaguchi, Yuugo Goto, Satoshi Teramoto, Katunobu Awane, Yoshitaka Yamamoto, Toshimasa Hamada
  • Patent number: 5897346
    Abstract: In producing a semiconductor device such as a thin film transistor (TFT), a silicon semiconductor film is formed on a substrate having an insulating surface, such as a glass substrate, and then a silicon nitride film is formed on the silicon semiconductor film. After that, a hydrogen ion, fluorine ion, or chlorine ion is introduced into the silicon semiconductor film through the silicon nitride film, and then the silicon semiconductor film into which an ion is introduced is heated in an atmosphere containing hydrogen, fluorine, chlorine or these mixture, to neutralize dangling bonds in the silicon semiconductor film and reduce levels in the silicon semiconductor film.
    Type: Grant
    Filed: November 27, 1996
    Date of Patent: April 27, 1999
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Naoaki Yamaguchi, Hongyong Zhang, Satoshi Teramoto, Hideto Ohnuma
  • Patent number: 5815226
    Abstract: An active matrix liquid crystal display having a high aperture ratio is provided. Retaining capacitors are created between a black matrix and pixel electrodes via a dielectric layer made from an organic resinous material or inorganic material. Those regions of the black matrix which cover TFTs are fully utilized. Therefore, wider area can be used to display an image than heretofore. In the present invention, the difference in relative dielectric constant between different dielectric layers is employed. Therefore, retaining capacitors can be created without the need to take account of parasitic capacitance.
    Type: Grant
    Filed: February 28, 1997
    Date of Patent: September 29, 1998
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Shunpei Yamazaki, Jun Koyama, Naoaki Yamaguchi, Katunobu Awane, Fumiaki Funada, Yoshitaka Yamamoto
  • Patent number: 5756364
    Abstract: It is intended to provide a technique of separately forming thin-film transistors disposed in a peripheral circuit area and those disposed in a pixel area in accordance with characteristics required therefor in a manufacturing process of semiconductor devices to constitute a liquid crystal display device. In an annealing step by laser light illumination, laser light is selectively applied to a semiconductor thin-film by partially masking it. For example, to illuminate the peripheral circuit area and the pixel area with laser light under different conditions in manufacture of an active matrix liquid crystal display device, laser light is applied at necessary illumination energy densities by using a mask. In this manner, a crystalline silicon film having a necessary degree of crystallinity in a selective manner can be obtained.
    Type: Grant
    Filed: November 22, 1995
    Date of Patent: May 26, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Koichiro Tanaka, Naoaki Yamaguchi
  • Patent number: 5736414
    Abstract: The aim of the present invention is to obtain a thin-film transistor which has a small OFF current. A film whose main component is aluminum and which will be the gate electrode is formed in an island shape, and a porous oxide layer is formed on its side surfaces by an anodic oxidation process. A source region and a drain region are then formed by performing impurity ion implantation. Further, the aforementioned oxide layer is removed, and lightly doped regions are formed by once again performing impurity ion implantation. In this way it is possible to obtain a construction which has lightly doped regions between the source/drain regions and the channel-forming regions.
    Type: Grant
    Filed: July 12, 1995
    Date of Patent: April 7, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Naoaki Yamaguchi
  • Patent number: 5648277
    Abstract: A method of manufacturing a semiconductor device comprises the steps of forming a first insulating film on a semiconductor layer, forming a gate electrode on the insulating film, pattering the first insulating film into a second insulating film so that a portion of the semiconductor layer is exposed while the second insulating film has extensions which extend beyond the side edges of the gate electrode, and performing ion introduction for forming impurity regions using the gate electrode and extensions of the gate insulating film as a mask. The condition of the ion introduction is varied in order to control the regions of the semiconductor layer to be added with the impurity and the concentration of the impurity therein.
    Type: Grant
    Filed: November 2, 1994
    Date of Patent: July 15, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoaki Yamaguchi, Yasuhiko Takemura
  • Patent number: 5620906
    Abstract: In producing a semiconductor device such as a thin film transistor (TFT), a silicon semiconductor film is formed on a substrate having an insulating surface, such as a glass substrate, and then a silicon nitride film is formed on the silicon semiconductor film. After that, a hydrogen ion, fluorine ion, or chlorine ion is introduced into the silicon semiconductor film through the silicon nitride film, and then the silicon semiconductor film into which an ion is introduced is heated in an atmosphere containing hydrogen, fluorine, chlorine or these mixture, to neutralize dangling bonds in the silicon semiconductor film and reduce levels in the silicon semiconductor film.
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: April 15, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Naoaki Yamaguchi, Hongyong Zhang, Satoshi Teramoto, Hideto Ohnuma
  • Patent number: 5612250
    Abstract: A method for manufacturing a thin film transistor having a crystalline silicon layer as an active layer comprises the steps of disposing a solution containing a catalyst for promoting a crystallization of silicon in contact with an amorphous silicon film, crystallizing the amorphous silicon at a relatively low temperature and then improving the crystallinity by irradiating the film with a laser light. The concentration of the catalyst in the crystallized silicon film can be controlled by controlling the concentration of the catalyst in the solution.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 18, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hisashi Ohtani, Akiharu Miyanaga, Hongyong Zhang, Naoaki Yamaguchi, Atsunori Suzuki
  • Patent number: 5605846
    Abstract: A process for manufacturing a semiconductor device, particularly a thin film transistor, by using a crystalline silicon film having excellent characteristics. The process comprises forming a silicon nitride film and an amorphous silicon film in contact thereto, introducing a catalyst element capable of promoting the crystallization of the amorphous silicon film by heating the amorphous silicon film, thereby crystallizing at least a part of the amorphous silicon film, and accelerating the crystallization by irradiating the silicon film with a laser beam or intense light equivalent thereto.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: February 25, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hisahi Ohtani, Akiharu Miyanaga, Hongyong Zhang, Naoaki Yamaguchi
  • Patent number: 5543352
    Abstract: A method for manufacturing a thin film transistor having a crystalline silicon layer as an active layer comprises the steps of disposing a solution containing a catalyst for promoting a crystallization of silicon in contact with an amorphous silicon film, crystallizing the amorphous silicon at a relatively low temperature and then improving the crystallinity by irradiating the film with a laser light. The concentration of the catalyst in the crystallized silicon film can be controlled by controlling the concentration of the catalyst in the solution.
    Type: Grant
    Filed: November 16, 1994
    Date of Patent: August 6, 1996
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Corporation
    Inventors: Hisashi Ohtani, Akiharu Miyanaga, Hongyong Zhang, Naoaki Yamaguchi, Atsunori Suzuki
  • Patent number: 5508209
    Abstract: In a thin film transistor (TFT), a mask is formed on a gate electrode, and a porous anodic oxide is formed in both sides of the gate electrode using a relatively low voltage. A barrier anodic oxide is formed between the gate electrode and the porous anodic oxide and on the gate electrode using a relatively high voltage. A gate insulating film is etched using the barrier anodic oxide as a mask. The porous anodic oxide is selectively etched after etching barrier anodic oxide, to obtain a region of an active layer on which the gate insulating film is formed and the other region of the active layer on which the gate insulating film is not formed. An element including at least one of oxygen, nitrogen and carbon is introduced into the region of the active layer at high concentration in comparison with a concentration of the other region of the active layer. Further, N- or P-type impurity is introduced into the active layer.
    Type: Grant
    Filed: September 27, 1994
    Date of Patent: April 16, 1996
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideto Ohnuma, Naoaki Yamaguchi, Yasuhiko Takemura