Patents by Inventor Hongyong Zhang

Hongyong Zhang 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: 6335540
    Abstract: An electro-optical device such as a liquid crystal device comprises a transparent substrate and a plurality of thin film transistors for driving pixel electrodes. In order to prevent an undesirable influence of light incident on the thin film transistors, a light shielding layer is interposed between the thin film transistors and the transparent substrate. Another portion of the light-shielding layer which corresponds to the pixel electrodes, has been changed to transparent by selectively oxidizing or nitriding the layer.
    Type: Grant
    Filed: February 18, 1999
    Date of Patent: January 1, 2002
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hongyong Zhang
  • Patent number: 6335541
    Abstract: A process for fabricating a highly stable and reliable semiconductor, comprising: coating the surface of an amorphous silicon film with a solution containing a catalyst element capable of accelerating the crystallization of the amorphous silicon film, and heat treating the amorphous silicon film thereafter to crystallize the film.
    Type: Grant
    Filed: April 15, 1996
    Date of Patent: January 1, 2002
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hisashi Ohtani, Akiharu Miyanaga, Takeshi Fukunaga, Hongyong Zhang
  • Patent number: 6335213
    Abstract: A method of fabricating silicon TFTs (thin-film transistors) is disclosed. The method comprises a crystallization step by laser irradiation effected after the completion of the device structure. First, amorphous silicon TFTs are fabricated. In each of the TFTs, the channel formation region, the source and drain regions are exposed to laser radiation illuminated from above or below the substrate. Then, the laser radiation is illuminated to crystallize and activate the channel formation region, and source and drain regions. After the completion of the device structure, various electrical characteristics of the TFTs are controlled. Also, the amorphous TFTs can be changed into polysilicon TFTs.
    Type: Grant
    Filed: April 14, 1999
    Date of Patent: January 1, 2002
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoto Kusumoto
  • Publication number: 20010052954
    Abstract: An active type liquid crystal display device, comprising an electrode being formed by using a transparent electrically conductive film constituting a pixel electrode, which allows the black matrix to be set as the common potential. Also claimed is an active type liquid crystal display device of the same type as above, comprising an electrode being formed on the same layer as that of the source line, which allows the black matrix to be set as the common potential.
    Type: Application
    Filed: March 1, 2001
    Publication date: December 20, 2001
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Tatsuya Ohori, Michiko Takei, Hongyong Zhang, Hideomi Suzawa, Naoaki Yamaguchi
  • Patent number: 6331723
    Abstract: An LDD structure is manufactured to have a desired aspect ratio of the height to the width of a gate electrode. The gate electrode is first deposited on a semiconductor substrate followed by ion implantation with the gate electrode as a mask to form a pair of impurity regions. The gate electrode is then anodic oxidized to form an oxide film enclosing the electrode. With the oxide film as a mask, highly doped regions are formed by ion implantation in order to define lightly doped regions between the highly doped regions and the channel region located therebetween.
    Type: Grant
    Filed: August 21, 1998
    Date of Patent: December 18, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Yasuhiko Takemura, Hongyong Zhang
  • Publication number: 20010051416
    Abstract: A semiconductor material and a method for forming the same, said semiconductor material having fabricated by a process comprising irradiating a laser beam or a high intensity light equivalent to a laser beam to an amorphous silicon film containing therein carbon, nitrogen, and oxygen each at a concentration of 5×1019 atoms·cm−3 or lower, preferably 1×1019 atoms·cm−3 or lower, without melting the amorphous silicon film. The present invention provides thin film semiconductors having high mobility at an excellent reproducibility, said semiconductor materials being useful for fabricating compact thin film semiconductor devices such as thin film transistors improved in device characteristics.
    Type: Application
    Filed: July 25, 2001
    Publication date: December 13, 2001
    Inventors: Shunpei Yamazaki, Hongyong Zhang, Naoto Kusumoto, Yasuhiko Takemura
  • Publication number: 20010045559
    Abstract: A method for improving the reliability and yield of a thin film transistor by controlling the crystallinity thereof. The method comprises the steps of forming a gate electrode on an island amorphous silicon film, injecting an impurity using the gate electrode as a mask, forming a coating film containing at least one of nickel, iron, cobalt, platinum and palladium so that it adheres to parts of the impurity regions, and annealing it at a temperature lower than the crystallization temperature of pure amorphous silicon to advance the crystallization starting therefrom and to crystallize the impurity regions and channel forming region.
    Type: Application
    Filed: July 31, 2001
    Publication date: November 29, 2001
    Inventors: Shunpei Yamazaki, Yasuhiko Takemura, Hongyong Zhang
  • Patent number: 6323071
    Abstract: A method for manufacturing a semiconductor device such as a thin film transistor using a crystal silicon film is provided. The crystal silicon film is obtained by selectively forming films, particles or clusters containing nickel, iron, cobalt, ruthenium, rhodium, paradium, osmium, iridium, platinum, scandium, titanium, vanadium, chrome, manganese, copper, zinc, gold, silver or silicide thereof in a form of island, line, stripe, dot or film on or under an amorphous silicon film and using them as a starting point, by advancing its crystallization by annealing at a temperature lower than a normal crystallization temperature of an amorphous silicon. A transistor whose leak current is low and a transistor in which a mobility is high are obtained in the same time in structuring a dynamic circuit having a thin film transistor by selectively forming a cover film on a semiconductor layer which is to become an active layer of the transistor and by thermally crystallizing it thereafter.
    Type: Grant
    Filed: January 19, 1999
    Date of Patent: November 27, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideki Uochi, Toru Takayama, Takeshi Fukunaga, Yasuhiko Takemura
  • Patent number: 6323932
    Abstract: To provide a technology for fabricating a high image quality liquid crystal display device, a set range of a cell gap for holding a liquid crystal layer is limited in accordance with a distance of a pixel pitch in which specifically, the cell gap is set to be a distance of one tenth of the pixel pitch, whereby the high image quality liquid crystal display device with no occurrence of image display failure caused by disturbances of an electric field such as disclination, can be realized.
    Type: Grant
    Filed: April 11, 1997
    Date of Patent: November 27, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd
    Inventors: Hongyong Zhang, Takeshi Fukunaga
  • Patent number: 6320224
    Abstract: The formation of contact holes and a capacitor is performed in a semiconductor integrated circuit such as an active matrix circuit. An interlayer insulator having a multilayer (a lower layer is silicon oxide; an upper layer is silicon nitride) each having different dry etching characteristic is formed. Using a first mask, the silicon nitride corresponding to the upper layer in the interlayer insulator is etched by dry etching. This etching is completed by using the silicon oxide corresponding to the lower layer as an etching stopper. A pattern is formed using a second mask to form selectively the silicon oxide corresponding to the lower layer. Thus a first portion that the silicon oxide and the silicon nitride are etched and a second portion that only silicon nitride is etched are obtained. The first portion is used as a contact hole. A capacitor is formed in the second portion.
    Type: Grant
    Filed: July 7, 1998
    Date of Patent: November 20, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hongyong Zhang
  • Patent number: 6319761
    Abstract: Method of fabricating TFTs starts with forming a nickel film selectively on a bottom layer which is formed on a substrate. An amorphous silicon film is formed on the nickel film and heated to crystallize it. The crystallized film is irradiated with infrared light to anneal it. Thus, a crystalline silicon film having excellent crystallinity is obtained. TFTs are built, using this crystalline silicon film.
    Type: Grant
    Filed: July 21, 1997
    Date of Patent: November 20, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Satoshi Teramoto
  • Patent number: 6320636
    Abstract: A structure is provided which avoids overlap of a pixel electrode and an intersecting portion of a gate line and a data line. For example, the pixel electrode is patterned such that its corner portion is intentionally cut out to avoid the intersecting portion. With this structure, the capacitance of a storage capacitor that is formed by an overlapping portion of the pixel electrode and a black matrix can be increased while short-circuiting in a third interlayer insulating film that is interposed between the pixel electrode and the black matrix is prevented.
    Type: Grant
    Filed: April 23, 2001
    Date of Patent: November 20, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Takeshi Fukunaga
  • Publication number: 20010041396
    Abstract: A method of manufacturing thin film field effect transistors is described. The channel region of the transistors is formed by depositing an amorphous semiconductor film in a first sputtering apparatus followed by thermal treatment for converting the amorphous phase to a polycrystalline phase. The gate insulating film is formed by depositing an oxide film in a second sputtering apparatus connected to the first apparatus through a gate valve. The sputtering for the deposition of the amorphous semiconductor film is carried out in an atmosphere comprising hydrogen in order to introduce hydrogen into the amorphous semiconductor film. On the other hand the gate insulating oxide film is deposited by sputtering in an atmosphere comprising oxygen.
    Type: Application
    Filed: June 11, 2001
    Publication date: November 15, 2001
    Inventors: Shunpei Yamazaki, Hongyong Zhang, Takashi Inushima, Takeshi Fukada
  • Publication number: 20010038124
    Abstract: A semiconductor device is manufactured by the use of a glass substrate which has previously been heated. An amorphous semiconductor layer is formed on the previously heated glass substrate and then crystallized by heat. By virtue of the previous heating, shrink of the glass substrate after the crystallization process is reduced. Accordingly, internal stress is not generated in the crystallized semiconductor layer. The semiconductor device thus manufactured is superior in electrical property.
    Type: Application
    Filed: December 7, 1999
    Publication date: November 8, 2001
    Inventor: HONGYONG ZHANG
  • Publication number: 20010035919
    Abstract: A metal electrode also serving as a black matrix is so formed as to cover the periphery of an ITO pixel electrode. A region where the pixel electrode and the metal electrode coextend also serves as an auxiliary capacitor. Since the auxiliary capacitor can be formed by using a thin insulating film, it can have a large capacitance. By virtue of the structure in which the black matrix also serves as the auxiliary capacitor, it is not necessary to provide an electrode dedicated to the auxiliary capacitor, thereby preventing reduction in aperture ratio. Further, the black matrix can completely shield a source line and a gate line from light.
    Type: Application
    Filed: March 23, 2001
    Publication date: November 1, 2001
    Applicant: Semiconductor Energy Laboratory Co., Ltd. Japanese corporation
    Inventor: Hongyong Zhang
  • Publication number: 20010034087
    Abstract: To provide a thin film transistor having a low OFF characteristic and to provide P-channel type and N-channel type thin film transistors where a difference in characteristics of the P-channel type and the N-channel type thin film transistors is corrected, a region 145 having a P-type behavior more potential than that of a drain region 146 is arranged between a channel forming region 134 and the drain region 146 in the P-channel type thin film transistor whereby the P-channel type thin film transistor having the low OFF characteristic can be provided and a low concentration impurity region 136 is arranged between a channel forming region 137 and a drain region 127 in the N-channel type thin film transistor whereby the N-channel type thin film transistor having the low OFF characteristic and where deterioration is restrained can be provided.
    Type: Application
    Filed: December 26, 2000
    Publication date: October 25, 2001
    Applicant: Semiconductor Energy Laboratory Co.
    Inventors: Hongyong Zhang, Satoshi Teramoto
  • Publication number: 20010030279
    Abstract: There is provided a laminated type photoelectric converter whose sensitivity is enhanced uniformly. In the photoelectric converter in which a photoelectric conversion device is laminated above a signal transfer device, the sensitivity is enhanced by providing bends on a lower electrode of the photoelectric conversion device and by confining light uniformly.
    Type: Application
    Filed: June 15, 2001
    Publication date: October 18, 2001
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Masayuki Sakakura
  • Publication number: 20010029071
    Abstract: An auxiliary capacitor for a pixel of an active matrix type liquid crystal display is provided without decreasing the aperture ratio. A transparent conductive film for a common electrode is formed under a pixel electrode constituted by a transparent conductive film with an insulation film provided therebetween. Further, the transparent conductive film for the common electrode is maintained at fixed potential, formed so as to cover a gate bus line and a source bus line, and configured such that signals on each bus line are not applied to the pixel electrode. The pixel electrode is disposed so that all edges thereof overlap the gate bus line and source bus line. As a result, each of the bus lines serves as a black matrix. Further, the pixel electrode overlaps the transparent conductive film for the common electrode to form a storage capacitor.
    Type: Application
    Filed: May 7, 2001
    Publication date: October 11, 2001
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoaki Yamaguchi, Yasuhiko Takemura
  • Patent number: 6300659
    Abstract: A thin-film transistor (TFT) which has a crystalline silicon active layer of excellent reliability and characteristics, and a method of fabricating such a TFT inexpensively are provided. In a TFT which has at least two low density impurity regions and a source/drain adjacent to a channel-forming region, catalyst elements which cause amorphous silicon to crystallize are included in the source/drain, and the density of said catalyst elements in the interface between the channel-forming region and the low-density impurity regions is less than that in the source/drain.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: October 9, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Toru Takayama, Yasuhiko Takemura
  • Patent number: 6300176
    Abstract: In an annealing process of illuminating a semiconductor thin film with laser light, in the case where the laser illumination is performed at an energy level that is lower than an output energy range that allows a laser apparatus to operate most stably, the laser output is fixed somewhere in the above output energy range and the illumination energy is changed by inserting or removing a light attenuation filter into or from the laser illumination optical path. As a result, the time required for the laser processing can be shortened.
    Type: Grant
    Filed: July 19, 1995
    Date of Patent: October 9, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Koichiro Tanaka