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: 6174374
    Abstract: A method for manufacturing a semiconductor device including preparing a multi-chamber system having at least first and second chambers, the first chamber for forming a film and the second chamber for processing an object with a laser light; processing a substrate in one of the first and second chambers; transferring the substrate to the other one of the first and second chambers; and processing the substrate in the other one of the chambers, wherein the first and second chambers can be isolated from one another by using a gate valve.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: January 16, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoto Kusumoto
  • Patent number: 6174757
    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: March 19, 1999
    Date of Patent: January 16, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Naoaki Yamaguchi, Hongyong Zhang, Satoshi Teramoto, Hideto Ohnuma
  • Patent number: 6172671
    Abstract: There is provided an active matrix type display in which thin film transistors having required characteristics are provided selectively in a pixel matrix portion and a peripheral driving circuit portion. In a structure having the pixel matrix portion and the peripheral driving circuit portion on the same substrate, N-channel type thin film transistors having source and drain regions formed through a non-self-alignment process and low concentrate impurity regions formed through a self-alignment process are formed in the pixel matrix portion and in an N-channel driver portion of the peripheral driving circuit portion. A P-channel type thin film transistor in which no low concentrate impurity region is formed and source and drain regions are formed only through the self-alignment process is formed in a P-channel driver portion of the peripheral driving circuit portion.
    Type: Grant
    Filed: June 3, 1999
    Date of Patent: January 9, 2001
    Assignee: Semiconductor Energy Laboratory, Inc.
    Inventors: Tsukasa Shibuya, Atsushi Yoshinouchi, Hongyong Zhang, Akira Takenouchi
  • Patent number: 6168980
    Abstract: A low temperature process for fabricating a high-performance and reliable semiconductor device in high yield, comprising forming a silicon oxide film as a gate insulator by chemical vapor deposition using TEOS as a starting material under an oxygen, ozone, or a nitrogen oxide atmosphere on a semiconductor coating having provided on an insulator substrate; and irradiating a pulsed laser beam or an intense light thereto to remove clusters of such as carbon and hydrocarbon to thereby eliminate trap centers from the silicon oxide film. Also claimed is a process comprising implanting nitrogen ions into a silicon oxide film and annealing the film thereafter using an infrared light, to thereby obtain a silicon oxynitride film as a gate insulator having a densified film structure, a high dielectric constant, and an improved withstand voltage.
    Type: Grant
    Filed: September 26, 1996
    Date of Patent: January 2, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hongyong Zhang
  • Patent number: 6166397
    Abstract: A display device having high definition and high reliability, and technology for manufacturing the same. In an active matrix type display device of integrated peripheral driving circuit type, pixel TFTs of an active matrix circuit 100 are not provided with LDD regions. Also, among circuits constituting peripheral driving circuits 101, 102, buffer circuits, of which a high withstand voltage and high-speed operation are required, are made with thin film transistors having floating island regions and base regions between source and drain regions of their active layers.
    Type: Grant
    Filed: January 4, 1999
    Date of Patent: December 26, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hongyong Zhang
  • Patent number: 6166399
    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: January 19, 1999
    Date of Patent: December 26, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoto Kusumoto
  • Patent number: 6160279
    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 an 100 where lead serving as a crystallization-promoting catalyst is introduced.
    Type: Grant
    Filed: July 27, 1998
    Date of Patent: December 12, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Toru Takayama
  • Patent number: 6159777
    Abstract: An improved method of forming a semiconductor device on a glass substrate is described. The method comprises forming a semiconductor film on a glass substrate, heating the semiconductor film by means of a heater to a predetermined temperature, exposing the semiconductor film to pulsed laser light after the semiconductor film has been heated to the predetermined temperature by the heating step. The thermal shock due to sharp temperature change is lessened by the pre-heating step.
    Type: Grant
    Filed: October 28, 1997
    Date of Patent: December 12, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Akira Takenouchi, Atsunori Suzuki, Hideto Ohnuma, Hongyong Zhang, Shunpei Yamazaki
  • Patent number: 6156627
    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.degree. 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: July 24, 1996
    Date of Patent: December 5, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideki Uochi, Akira Miyanaga, Hisashi Ohtani
  • Patent number: 6147375
    Abstract: A wiring formed on a substrate is oxidized and the oxide is used as a mask for forming source and drain impurity regions of a transistor, or as a material for insulating wirings from each other, or as a dielectric of a capacitor. The thickness of the oxide is determined depending on the purpose of the oxide. In a transistor adapted to be used in an active-matrix liquid-crystal display, the channel length, 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 fields are applied to these offset regions from the gate electrode.
    Type: Grant
    Filed: September 11, 1998
    Date of Patent: November 14, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Akira Mase, Masaaki Hiroki, Yasuhiko Takemura, Hongyong Zhang, Hideki Uochi
  • Patent number: 6143661
    Abstract: A method of fabricating a semiconductor device by the use of laser crystallization steps is provided. During these crystallization steps, an amorphous or polycrystalline semiconductor is crystallized by laser irradiation in such a way that generation of ridges is suppressed. Two separate laser crystallization steps are carried out. First, a laser irradiation step is performed in a vacuum, using somewhat weak laser light. Then, another laser irradiation step is performed in a vacuum, in the atmosphere, or in an oxygen ambient with intenser laser light. The first laser irradiation conducted in a vacuum does not result in satisfactory crystallization. However, this irradiation can suppress generation of ridges. The second laser irradiation step is performed in a vacuum, in the atmosphere, or in an oxygen ambient to achieve sufficient crystallization, but no ridges are produced.
    Type: Grant
    Filed: August 13, 1998
    Date of Patent: November 7, 2000
    Assignees: Semiconductor Energy Laboratory Co., Ltd., Sharp Kabushiki Kaisha
    Inventors: Takamasa Kousai, Hongyong Zhang, Akiharu Miyanaga
  • Patent number: 6140165
    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, Nickel 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.degree. 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: September 6, 1996
    Date of Patent: October 31, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Toru Takayama, Yasuhiko Takemura, Akiharu Miyanaga, Hisashi Ohtani
  • Patent number: 6140164
    Abstract: A resist mask used for forming a region of aluminum is made small by ashing to form a new mask. Anodic oxidation is carried out with an anode of the region of aluminum to form porous anodic oxidation films. In this anodic oxidation step, the mask can control the directions of openings of the porous anodic oxidation films (anisotropy). If the impurity ions are implanted using the porous anodic oxidation films as masks, the amount of impurity ions implanted into an active layer can be adjusted. Using this, an LDD region can be formed.
    Type: Grant
    Filed: November 25, 1996
    Date of Patent: October 31, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventor: Hongyong Zhang
  • Patent number: 6124155
    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: March 23, 1998
    Date of Patent: September 26, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoto Kusumoto
  • Patent number: 6121076
    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 nickel serving as a crystallization-promoting catalyst is introduced.
    Type: Grant
    Filed: August 4, 1997
    Date of Patent: September 19, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Toru Takayama, Yasuhiko Takemura
  • Patent number: 6115088
    Abstract: The present invention provides an active matrix type display device having a high aperture ratio and a required auxiliary capacitor. A source line and a gate line are overlapped with part of a pixel electrode. This overlapped region functions to be a black matrix. Further, an electrode pattern made of the same material as the pixel electrode is disposed to form the auxiliary capacitor by utilizing the pixel electrode. It allows a required value of auxiliary capacitor to be obtained without dropping the aperture ratio. Also, it allows the electrode pattern to function as a electrically shielding film for suppressing the cross-talk between the source and gate lines and the pixel electrode.
    Type: Grant
    Filed: September 3, 1997
    Date of Patent: September 5, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Satoshi Teramoto
  • Patent number: 6110770
    Abstract: A process for fabricating a semiconductor by crystallizing a silicon film in a substantially amorphous state by annealing it at a temperature not higher than the crystallization temperature of amorphous silicon, and it comprises forming selectively, on the surface or under an amorphous silicon film, a coating, particles, clusters, and the like containing nickel, iron, cobalt, platinum or palladium either as a pure metal or a compound thereof such as a silicide, a salt, and the like, shaped into island-like portions, linear portions, stripes, or dots; and then annealing the resulting structure at a temperature lower than the crystallization temperature of an amorphous silicon by 20 to 150.degree. C.
    Type: Grant
    Filed: January 13, 1999
    Date of Patent: August 29, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Hideki Uochi, Toru Takayama, Shunpei Yamazaki, Yasuhiko Takemura
  • Patent number: 6104067
    Abstract: A semiconductor device comprising a structure in which a plurality of gate electrodes connected in common are arranged superposed on the active layer, wherein the widest gate electrode is located on the drain side. In this manner, local difference in electric field intensity applied to the channel region can be corrected to prevent a local degradation or breakdown from occurring.
    Type: Grant
    Filed: July 28, 1997
    Date of Patent: August 15, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Satoshi Teramoto
  • Patent number: 6104461
    Abstract: An inorganic layer such as a silicon nitride film, a silicon oxide film, or a silicon oxynitride film is interposed between a pixel electrode and a black matrix that constitute a storage capacitor. This structure increases the capacitance per unit area.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: August 15, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Masayuki Sakakura, Shirou Isoda
  • Patent number: 6096581
    Abstract: A method for operating an active matrix display device having an active matrix circuit, a column driver circuit and a scan driver circuit including driving the active matrix circuit by the column driver circuit and the scan driver circuit, wherein each of the active matrix circuit, column driver circuit and scan driver circuit includes by thin film transistors and wherein a variation in threshold voltages of the thin film transistors of the column driver circuit is not greater than 0.05 V.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: August 1, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hongyong Zhang, Naoaki Yamaguchi, Yasuhiko Takemura