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: 6987283
    Abstract: In thin film transistors (TFTs) having an active layer of crystalline silicon adapted for mass production, a catalytic element is introduced into doped regions of an amorphous silicon film by ion implantation or other means. This film is crystallized at a temperature below the strain point of the glass substrate. Further, a gate insulating film and a gate electrode are formed. Impurities are introduced by a self-aligning process. Then, the laminate is annealed below the strain point of the substrate to activate the dopant impurities. On the other hand, Neckel or other element is also used as a catalytic element for promoting crystallization of an amorphous silicon film. First, this catalytic element is applied in contact with the surface of the amorphous silicon film. The film is heated at 450 to 650° C. to create crystal nuclei. The film is further heated at a higher temperature to grow the crystal grains. In this way, a crystalline silicon film having improved crystallinity is formed.
    Type: Grant
    Filed: June 27, 2002
    Date of Patent: January 17, 2006
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Toru Takayama, Yasuhiko Takemura, Akiharu Miyanaga, Hisashi Ohtani
  • Patent number: 6982768
    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: Grant
    Filed: March 1, 2001
    Date of Patent: January 3, 2006
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Tatsuya Ohori, Michiko Takei, Hongyong Zhang, Hideomi Suzawa, Naoaki Yamaguchi
  • Publication number: 20050287722
    Abstract: Method of fabricating thin-film transistors in which contact with connecting electrodes becomes reliable. When contact holes are formed, the bottom insulating layer is subjected to a wet etching process, thus producing undercuttings inside the contact holes. In order to remove the undercuttings, a light etching process is carried out to widen the contact holes. Thus, tapering section are obtained, and the covering of connection wiring is improved.
    Type: Application
    Filed: August 26, 2005
    Publication date: December 29, 2005
    Inventor: Hongyong Zhang
  • Patent number: 6977392
    Abstract: An insulated-gate field-effect transistor adapted to be used in an active-matrix liquid-crystal display. The channel length, or the distance between the source region and the drain region, is made larger than the length of the gate electrode taken in the longitudinal direction of the channel. Offset regions are formed in the channel region on the sides of the source and drain regions. No or very weak electric field is applied to these offset regions from the gate electrode.
    Type: Grant
    Filed: March 18, 2003
    Date of Patent: December 20, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Akira Mase, Masaaki Hiroki, Yasuhiko Takemura, Hongyong Zhang, Hideki Uochi, Hideki Nemoto
  • Patent number: 6974763
    Abstract: A substrate on which an amorphous silicon film is formed is placed in a vacuum chamber. An organic nickel vapor or gas is introduced into the chamber and then decomposed, so that a thin film containing nickel (a catalytic element which promotes crystallization of the amorphous silicon film) or a compound thereof is uniformly deposited on the amorphous silicon film. After that, the substrate is heated at a temperature such as 550° C. lower than a normal solid phase growth temperature for a short time such as 4 hours, to uniformly crystallize the amorphous silicon film. A crystalline silicon film is obtained by this crystallization process.
    Type: Grant
    Filed: October 25, 2000
    Date of Patent: December 13, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideki Uochi, Akira Miyanaga, Hisashi Ohtani
  • Publication number: 20050260834
    Abstract: A preparing method of a semiconductor, particularly a preparing method of a polycrystal semiconductor film which has a good electrical property is disclosed. In order to obtain a non-crystalline silicon film containing a lot of combination of hydrogen and silicon, a forming process of a non-crystalline silicon film by a low temperature gas phase chemical reaction, a process of a heat annealing to produce a lot of dangling bonds of silicon, so as to draw out hydrogen from said non-crystalline silicon film, and a process of applying a laser irradiation to said non-crystal silicon film having a lot of dangling bond of silicon are conducted.
    Type: Application
    Filed: August 1, 2005
    Publication date: November 24, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoto Kusumoto
  • Patent number: 6964890
    Abstract: Thin-film semiconductor devices such as TFTs (thin-film transistors) and methods of fabricating the same. TFTs are formed on an insulating substrate. First, a substantially amorphous semiconductor coating is formed on the substrate. A protective coating transparent to laser radiation is formed on the semiconductor coating. The laminate is irradiated with laser radiation to improve the crystallinity of the semiconductor coating. Then, the protective coating is removed to expose the surface of the semiconductive coating. A coating for forming a gate-insulating film is formed. Subsequently, gate electrodes are formed. Another method relates to fabrication of semiconductor devices such as TFTs on an insulating substrate. After forming a first coating consisting mainly of aluminum nitride, a second coating consisting principally of silicon oxide is formed. Semiconductor devices such as TFTs or semiconductor circuits are built on the second coating serving as a base layer.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: November 15, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hongyong Zhang, Yasuhiko Takemura
  • Publication number: 20050245053
    Abstract: After a pattern is transferred on silicon film crystallized by annealing, the silicon film is annealed by radiation of intense rays for a short time. Especially, in the crystallizing process by annealing, an element which promotes crystallization such as nickel is doped therein. The area not crystallized by annealing is also crystallized by radiation of intense rays and a condensed silicon film is formed. After a metal element which promotes crystallization is doped, annealing by light for a short time is performed by radiating intense rays onto the silicon film crystallized by annealing in an atmosphere containing halide. After the surface of the silicon film is oxidized by heating or by radiating intense rays in a halogenated atmosphere and an oxide film is formed on the silicon film, the oxide film is then etched. As a result, nickel in the silicon film is removed.
    Type: Application
    Filed: July 5, 2005
    Publication date: November 3, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideto Ohnuma, Yasuhico Takemura
  • Patent number: 6960812
    Abstract: A method of forming an oxide film and a method of manufacturing an electronic device utilizing the oxide film is disclosed. A silicon oxide film is formed on a substrate by sputtering. Therefore, the film formation is carried out at a low temperature. The sputtering atmosphere comprises an oxidizing gas and an inert gas such as argon. In order to prevent fixed electric charges from being generated in the film and to obtain an oxide film of good properties, the proportion of argon is adjusted to 20% or less. Alternatively, a gas including halogen elements such as fluorine is added to the above sputtering atmosphere at a proportion less than 20%. Hereupon, alkali ions and dangling bonds of silicon in the oxide film are neutralized by the halogen elements, whereby a fine oxide film is obtained.
    Type: Grant
    Filed: June 12, 2003
    Date of Patent: November 1, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hongyong Zhang
  • Publication number: 20050231657
    Abstract: There are provided a first gate electrode of a first MOS transistor formed on a semiconductor layer via a gate insulating film, a second gate electrode of a second MOS transistor formed on the semiconductor layer via the gate insulating film at a distance from the first gate electrode, first and second one conductivity type impurity introduced regions formed in the semiconductor layer on both sides of the first gate electrode to serve as source/drain of the first MOS transistor, and first and second opposite conductivity type impurity introduced regions formed in the semiconductor layer on both sides of the second gate electrode to serve as source/drain of the second MOS transistor, whereby one of the first and second opposite conductivity type impurity introduced regions is formed to contact mutually to the second one conductivity type impurity introduced region.
    Type: Application
    Filed: June 16, 2005
    Publication date: October 20, 2005
    Inventors: Hongyong Zhang, Noriko Uchida
  • Publication number: 20050224796
    Abstract: There is provided a method by which lightly doped drain (LDD) regions can be formed easily and at good yields in source/drain regions in thin film transistors possessing gate electrodes covered with an oxide covering. A lightly doped drain (LDD) region is formed by introducing an impurity into an island-shaped silicon film in a self-aligning manner, with a gate electrode serving as a mask. First, low-concentration impurity regions are formed in the island-shaped silicon film by using rotation-tilt ion implantation to effect ion doping from an oblique direction relative to the substrate. Low-concentration impurity regions are also formed below the gate electrode at this time. After that, an impurity at a high concentration is introduced normally to the substrate, so forming high-concentration impurity regions. In the above process, a low-concentration impurity region remains below the gate electrode and constitutes a lightly doped drain region.
    Type: Application
    Filed: May 26, 2005
    Publication date: October 13, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Yasuhiko Takemura, Toshimitsu Konuma, Hideto Ohnuma, Naoaki Yamaguchi, Hideomi Suzawa, Hideki Uochi
  • Publication number: 20050206830
    Abstract: A liquid crystal display apparatus containing an image sensor, which comprises a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit for driving the active matrix circuit, and a sensor part, integrated on one substrate, wherein the sensor part is sealed and protected with a sealing part and a counter substrate.
    Type: Application
    Filed: May 31, 2005
    Publication date: September 22, 2005
    Inventors: Hongyong Zhang, Masayuki Sakakura
  • Publication number: 20050202609
    Abstract: A display device using a novel semiconductor device, which includes a pixel matrix, an image sensor, and a peripheral circuit for driving those, that is, which has both a camera function and a display function, and is made intelligent is provided and a method of manufacturing the same is also provided. One pixel includes a semiconductor device for display and a semiconductor for light reception, that is, one pixel includes semiconductor devices (insulated gate-type field effect semiconductor device) for controlling both display and light reception, so that the display device having a picture reading function is made miniaturized and compact.
    Type: Application
    Filed: March 8, 2005
    Publication date: September 15, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Masayuki Sakakura, Hideaki Kuwabara
  • Patent number: 6939749
    Abstract: A process for fabricating a thin film transistor, which comprises crystallizing an amorphous silicon film, forming thereon a gate insulating film and a gate electrode, implanting impurities in a self-aligned manner, adhering a coating containing a catalyst element which accelerates the crystallization of the silicon film, and annealing the resulting structure at a temperature lower than the deformation temperature of the substrate to activate the doped impurities. Otherwise, the catalyst element can be incorporated into the structure by introducing it into the impurity region by means of ion implantation and the like.
    Type: Grant
    Filed: March 25, 2003
    Date of Patent: September 6, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd
    Inventors: Hongyong Zhang, Toru Takayama, Yasuhiko Takemura
  • Publication number: 20050189541
    Abstract: A structure for reducing the OFF current of an active matrix display. In the active matrix display, plural TFTs are connected in series with each one pixel electrode. Of these TFTs connected in series, at least one TFT excluding the TFTs located at opposite ends is maintained in conduction. Alternatively, at least one capacitor is connected between the junction of the drain and source of each TFT connected in series and an AC grounded point. Thus, the amount of electric charge released from auxiliary capacitors during cutoff of the TFTs is reduced.
    Type: Application
    Filed: April 25, 2005
    Publication date: September 1, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hongyong Zhang
  • Patent number: 6937306
    Abstract: A liquid crystal display apparatus containing an image sensor, which comprises a liquid crystal display part comprising an active matrix circuit, a peripheral driver circuit for driving the active matrix circuit, and a sensor part, integrated on one substrate, wherein the sensor part is sealed and protected with a sealing part and a counter substrate.
    Type: Grant
    Filed: December 22, 2003
    Date of Patent: August 30, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Masayuki Sakakura
  • Publication number: 20050181583
    Abstract: A semiconductor material and a method for forming the same, said semiconductor material having produced by a process comprising melting a noncrystal semiconductor 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, by irradiating a laser beam or a high intensity light equivalent to a laser beam to said noncrystal semiconductor film, and then recrystallizing the thus molten amorphous silicon film. The present invention provides thin film semiconductors having high mobility at an excellent reproducibility, said semiconductor materials being useful for fabricating thin film semiconductor devices such as thin film transistors improved in device characteristics.
    Type: Application
    Filed: April 14, 2005
    Publication date: August 18, 2005
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hongyong Zhang, Naoto Kusumoto, Yasuhiko Takemura
  • Patent number: 6924213
    Abstract: After a pattern is transferred on silicon film crystallized by annealing, the silicon film is annealed by radiation of intense rays for a short time. Especially, in the crystallizing process by annealing, an element which promotes crystallization such as nickel is doped therein. The area not crystallized by annealing is also crystallized by radiation of intense rays and a condensed silicon film is formed. After a metal element which promotes crystallization is doped, annealing by light for a short time is performed by radiating intense rays onto the silicon film crystallized by annealing in an atmosphere containing halide. After the surface of the silicon film is oxidized by heating or by radiating intense rays in a halogenated atmosphere and an oxide film is formed on the silicon film, the oxide film is then etched. As a result, nickel in the silicon film is removed.
    Type: Grant
    Filed: September 24, 2002
    Date of Patent: August 2, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideto Ohnuma, Yasuhiko Takemura
  • Patent number: 6924506
    Abstract: A silicon film provided on a blocking film 102 on a substrate 101 is made amorphous by doping Si+, and in a heat-annealing process, crystallization is started in parallel to a substrate from an area 100 where lead serving as a crystallization-promoting catalyst is introduced.
    Type: Grant
    Filed: December 1, 2000
    Date of Patent: August 2, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Toru Takayama
  • Patent number: 6919239
    Abstract: A method for forming a semiconductor device is disclosed. The method comprises the step of irradiating a laser light to a surface of a semiconductor through a mask provided on said surface in an atmosphere comprising an impurity of one conductivity type to diffuse said impurity into a region of said semiconductor.
    Type: Grant
    Filed: December 4, 2003
    Date of Patent: July 19, 2005
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hongyong Zhang