Patents by Inventor Takeshi Fukada

Takeshi Fukada 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: 6210997
    Abstract: A method for manufacturing a semiconductor device comprises the steps of forming a semiconductor film on a substrate, oxidizing a surface of said semiconductor film in an oxidizing atmosphere with said semiconductor film heated or irradiated with light, and further depositing an oxide film on the oxidized surface of the semiconductor film by PVD or CVD. The first oxide film has a good interface condition with the semiconductor film and a characteristics of an insulated gate field effect transistor can be improved if the first oxide-film and the second oxide film are used as a gate insulating film.
    Type: Grant
    Filed: July 28, 1999
    Date of Patent: April 3, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiroki Adachi, Akira Takenouchi, Takeshi Fukada, Hiroshi Uehara, Yasuhiko Takemura
  • Patent number: 6204519
    Abstract: A thin film semiconductor device comprising a substrate having an insulating surface, gate electrodes disposed on the insulating surface, gate insulating films disposed on upper portions of the gate electrodes, and thin film semiconductors disposed on the gate insulating films and including channel forming regions, source regions and drain regions. Two kinds of thin film semiconductor unit are disposed on the substrate. A first thin film semiconductor unit includes the thin film semiconductor of polycrystal, an insulating film covering an upper portion of the channel forming region, impurity semiconductor films doped with trivalent or pentavalent impurities and covering the source region and the drain region, and conductive films disposed on the impurity semiconductor films. A second thin film semiconductor unit includes the thin film semiconductor of amorphous, and other components similar to the first thin film semiconductor unit.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: March 20, 2001
    Assignee: Semicondutor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Toshiji Hamatani, Takeshi Fukada
  • Patent number: 6177302
    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: Grant
    Filed: September 22, 1994
    Date of Patent: January 23, 2001
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Hongyong Zhang, Takashi Inushima, Takeshi Fukada
  • Patent number: 6163055
    Abstract: An interlayer insulating film (104) that is formed on a substrate (101) so as to cover TFTs (102, 103) is planarized by mechanical polishing that is typified by CMP. Pixel electrodes (106, 107) are formed on the interlayer insulating film (104) and an insulating layer (108) is formed so as to cover the pixel electrodes. The insulating layer (108) is planarized by second mechanical polishing so that the surfaces of the pixel electrodes become flush with those of resulting buried insulating layers (112, 113). Since the pixel electrode surfaces have no steps, such problems as alignment failures of a liquid crystal material and a contrast reduction due to diffused reflection of light can be prevented.
    Type: Grant
    Filed: March 23, 1998
    Date of Patent: December 19, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd
    Inventors: Yoshiharu Hirakata, Takeshi Fukada, Shunpei Yamazaki
  • Patent number: 6025630
    Abstract: A silicon oxide film is formed to cover an island non-monocrystalline silicon region by plasma CVD using an organic silane having ethoxy groups (e.g., TEOS) and oxygen as raw materials, while hydrogen chloride or a chlorine-containing hydrocarbon (e.g., trichloroethylene) of a fluorine-containing gas is added to the plasma CVD atmosphere, preferably in an amount of from 0.01 to 1 mol % of the atmosphere so as to reduce the alkali elements from the silicon oxide film formed and to improve the reliability of the film. Prior to forming the silicon oxide film, the silicon region may be treated in a plasma atmosphere containing oxygen and hydrogen chloride or a chlorine-containing hydrocarbon. The silicon oxide film is obtained at low temperatures and this has high reliability usable as a gate-insulating film in a semiconductor device.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: February 15, 2000
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Fukada, Mitsunori Sakama, Yukiko Uehara, Hiroshi Uehara
  • Patent number: 6008076
    Abstract: A thin film transistor and a semiconductor device and a method for forming the same. A silicon thin film formed on an insulating substrate is heated at 550 to 800.degree. C. so that it has crystallinity, and a thin film transistor is formed using the crystalline silicon film thus obtained. Thermal contraction of the insulating substrate is set in a range of 30 to 500 ppm in the heating process, so that the thin film transistor has high mobility, low threshold voltage and high off-resistance. Thermal contraction of the insulating substrate may be also set 100 ppm or less in a heating process after a patterning treatment in a thin film transistor producing process.
    Type: Grant
    Filed: November 6, 1996
    Date of Patent: December 28, 1999
    Assignee: Semicoductor Energy Laboratory Co., Ltd.
    Inventors: Mitsufumi Codama, Yukio Yamauchi, Naoya Sakamoto, Takeshi Fukada
  • Patent number: 5966594
    Abstract: A method for manufacturing a semiconductor device comprises the steps of forming a semiconductor film on a substrate, oxidizing a surface of said semiconductor film in an oxidizing atmosphere with said semiconductor film heated or irradiated with light, and further depositing an oxide film on the oxidized surface of the semiconductor film by PVD or CVD. The first oxide film has a good interface condition with the semiconductor film and a characteristics of an insulated gate field effect transistor can be improved if the first oxide film and the second oxide film are used as a gate insulating film.
    Type: Grant
    Filed: December 18, 1996
    Date of Patent: October 12, 1999
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiroki Adachi, Akira Takenouchi, Takeshi Fukada, Hiroshi Uehara, Yasuhiko Takemura
  • Patent number: 5929487
    Abstract: Improved method of heat-treating a glass substrate, especially where the substrate is thermally treated (such as formation of films, growth of films, and oxidation) around or above its strain point. If devices generating heat are formed on the substrate, it dissipates the heat well. An aluminum nitride film is formed on at least one surface of the substrate. This aluminum nitride film acts as a heat sink and prevents local concentration of heat produced by the devices such as TFTs formed on the glass substrate surface.
    Type: Grant
    Filed: June 5, 1995
    Date of Patent: July 27, 1999
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takeshi Fukada, Mitsunori Sakama, Satoshi Teramoto
  • Patent number: 5866932
    Abstract: A silicon oxide film is formed to cover an island non-monocrystalline silicon region by plasma CVD using an organic silane having ethoxy groups (e.g., TEOS) and oxygen as raw materials, while hydrogen chloride or a chlorine-containing hydrocarbon (e.g., trichloroethylene) of a fluorine-containing gas is added to the plasma CVD atmosphere, preferably in an amount of from 0.01 to 1 mol % of the atmosphere so as to reduce the alkali elements from the silicon oxide film formed and to improve the reliability of the film. Prior to forming the silicon oxide film, the silicon region may be treated in a plasma atmosphere containing oxygen and hydrogen chloride or a chlorine-containing hydrocarbon. The silicon oxide film is obtained at low temperatures and this has high reliability usable as a gate-insulating film in a semiconductor device.
    Type: Grant
    Filed: October 21, 1996
    Date of Patent: February 2, 1999
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Fukada, Mitsunori Sakama, Yukiko Uehara, Hiroshi Uehara
  • Patent number: 5861103
    Abstract: Each of a pair of electrodes is provided in high-frequency power supply. A sample placed on the one of electrodes is etched by RIE (reactive ion etching) method. At the time, the power supply connected to the other electrode opposite to the sample is actuated first, and then the power supply of the one electrode on which the sample has been placed is actuated. And then the power supply connected to the other electrode is stopped. Therefore a bias voltage applied to the sample is gradually varied to suppress the abrupt application of a voltage to the sample.
    Type: Grant
    Filed: July 29, 1996
    Date of Patent: January 19, 1999
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Fukada, Hideomi Suzawa
  • Patent number: 5837614
    Abstract: A silicon oxide film is formed to cover an island non-monocrystalline silicon region by plasma CVD using an organic silane having ethoxy groups (e.g., TEOS) and oxygen as raw materials, while hydrogen chloride or a chlorine-containing hydrocarbon (e.g., trichloroethylene) of a fluorine-containing gas is added to the plasma CVD atmosphere, preferably in an amount of from 0.01 to 1 mol % of the atmosphere so as to reduce the alkali elements from the silicon oxide film formed and to improve the reliability of the film. Prior to forming the silicon oxide film, the silicon region may be treated in a plasma atmosphere containing oxygen and hydrogen chloride or a chlorine-containing hydrocarbon. The silicon oxide film is obtained at low temperatures and this has high reliability usable as a gate-insulating film in a semiconductor device.
    Type: Grant
    Filed: January 7, 1997
    Date of Patent: November 17, 1998
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Takeshi Fukada, Mitsunori Sakama, Yukiko Uehara, Hiroshi Uehara
  • Patent number: 5674304
    Abstract: A method of heat-treating a glass substrate where the substrate is thermally treated (such as the formation of films, growth of films, and oxidation) around or above its strain point. After thermally treating the substrate around or above its strain point the glass substrate may be slowly cooled at a rate of 0.01.degree. to 0.5.degree. C./min to achieve maximum shrinkage of the substrate. Following further thermal treatments the substrate may be quickly cooled at a rate of 10.degree. C./min to 300.degree. C./sec to suppress shrinkage of the glass substrate. The substrate can have films such as aluminum nitrate films, silicon oxide films, silicon films, insulating films, semiconductor films, etc. Film formation can occur either before or after thermal treatment of the substrate around or above its strain point and before further thermal treatments.
    Type: Grant
    Filed: September 23, 1994
    Date of Patent: October 7, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takeshi Fukada, Mitsunori Sakama, Satoshi Teramoto
  • Patent number: 5663077
    Abstract: A method for manufacturing a semiconductor device comprises the steps of forming a semiconductor film on a substrate, oxidizing a surface of said semiconductor film in an oxidizing atmosphere with said semiconductor film heated or irradiated with light, and further depositing an oxide film on the oxidized surface of the semiconductor film by PVD or CVD. The first oxide film has a good interface condition with the semiconductor film and a characteristics of an insulated gate field effect transistor can be improved if the first oxide film and the second oxide film are used as a gate insulating film.
    Type: Grant
    Filed: July 26, 1994
    Date of Patent: September 2, 1997
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiroki Adachi, Akira Takenouchi, Takeshi Fukada, Hiroshi Uehara, Yasuhiko Takemura
  • Patent number: 5576222
    Abstract: An image sensor (10) has a substrate (1), an active layer (3') having a source region and a drain region placed on said substrate (1), a gate insulation layer (4') placed on said active layer, and a gate electrode layer (5') on said gate insulation layer (4'). The active layer (3') is produced by the steps of producing amorphous silicon layer by using disilane gas (Si.sub.2 H.sub.6) through Low Pressure CVD process, and annealing said layer at 500.degree.-650.degree. C. for 4-50 hours in nitrogen gas atmosphere. The gate insulation layer (4') is produced through oxidation of the surface of the active layer at high temperature around 900.degree.-1100.degree. C. The oxidation process at high temperature improves the anneal process and improves the active layer. Thus, an image sensor with uniform characteristics is obtained with improved producing yield rate.
    Type: Grant
    Filed: October 18, 1994
    Date of Patent: November 19, 1996
    Assignees: TDK Corp., Semiconductor Energy Laboratory Co. Ltd.
    Inventors: Michio Arai, Masaaki Ikeda, Kazushi Sugiura, Nobuo Furukawa, Mitsufumi Kodama, Yukio Yamauchi, Naoya Sakamoto, Takeshi Fukada, Masaaki Hiroki, Ichirou Takayama
  • Patent number: 5442198
    Abstract: A MOS-FET transistor is produced on a substrate made of glass which has a non single crystal semiconductor film (2'). The average diameter of a crystal grain in said film is in the range between 0.5 times and 4 times of thickness of said film, and said average diameter is 250 .ANG.-8000 .ANG., and said film thickness is 500 .ANG.-2000 .ANG.. The density of oxygen in the semiconductor film (2') is less than 2.times.10.sup.19 /cm.sup.3. A photo sensor having PIN structure is also produced on the substrate, to provide an image sensor for a facsimile transmitter together with the transistors. Said film (2') is produced by placing amorphous silicon film on the glass substrate through CVD process using disilane gas, and effecting solid phase growth to said amorphous silicon film by heating the substrate together with said film in nitrogen gas atmosphere. The film (2') thus produced is subject to implantation of dopant for providing a transistor.
    Type: Grant
    Filed: January 31, 1994
    Date of Patent: August 15, 1995
    Assignees: TDK Corporation, Semiconductor Energy Lab. Co., Ltd.
    Inventors: Michio Arai, Masaaki Ikeda, Kazushi Sugiura, Nobuo Furukawa, Mitsufumi Kodama, Yukio Yamauchi, Naoya Sakamoto, Takeshi Fukada, Masaaki Hiroki, Ichirou Takayama
  • Patent number: 5330578
    Abstract: A plasma gaseous reaction apparatus including a reaction chamber, a system for supplying reaction gas to the reaction chamber and an exhaust system for exhausting unnecessary reaction products. Specifically, the apparatus includes a pair of facing electrodes disposed in the reaction chamber which are covered by shields except the area in which the electrodes face each other. The shields may include a first and second shield wherein the inner first shield is electrically insulated from the electrodes and the outer second shield is kept at earth potential. The apparatus further includes a substrate container for supporting substrates which surrounds the substrates by a frame. The outside of the substrate container is kept in the earth potential and is covered by a conductor plate electrically insulated from the container. The shields and substrate container are configured such that plasma generated by electric power supplied by the electrodes is confined in a space surrounded by the shields and the container.
    Type: Grant
    Filed: March 11, 1992
    Date of Patent: July 19, 1994
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Mitsunori Sakama, Takeshi Fukada, Mitsuhiro Ichijo, Hisashi Abe
  • Patent number: 5298455
    Abstract: A MOS-FET transistor is produced on a substrate made of glass which has a non single crystal semiconductor film (2'). The average diameter of a crystal grain in said film is in the range between 0.5 times and 4 times of thickness of said film, and said average diameter is 250 .ANG.-8000 .ANG. , and said film thickness is 500 .ANG.-2000 .ANG.. The density of oxygen in the semiconductor film (2') is less than 2.times.10.sup.19 /cm.sup.3. A photo sensor having PIN structure is also produced on the substrate, to provide an image sensor for a facsimile transmitter together with the transistors. Said film (2') is produced by placing amorphous silicon film on the glass substrate through CVD process using disilane gas, and effecting solid phase growth to said amorphous silicon film by heating the substrate together with said film in nitrogen gas atmosphere. The film (2') thus produced is subject to implantation of dopant for providing a transistor.
    Type: Grant
    Filed: January 27, 1992
    Date of Patent: March 29, 1994
    Assignee: TDK Corporation
    Inventors: Michio Arai, Masaaki Ikeda, Kazushi Sugiura, Nobuo Furukawa, Mitsufumi Kodama, Yukio Yamauchi, Naoya Sakamoto, Takeshi Fukada, Masaaki Hiroki, Ichirou Takayama
  • Patent number: 5296405
    Abstract: An improved semiconductor processing is disclosed. In the manufacturing process, a semiconductor layer is formed and then undergoes photo annealing. A neutralizer is then introduced to the photoannealed semiconductor. The semiconductor thus formed demonstrates the SEL effect instead of the Staebler-Wronski effect.
    Type: Grant
    Filed: August 24, 1992
    Date of Patent: March 22, 1994
    Assignee: Semiconductor Energy Laboratory Co.., Ltd.
    Inventors: Shunpei Yamazaki, Kunio Suzuki, Susumu Nagayama, Takashi Inujima, Masayoshi Abe, Takeshi Fukada, Mikio Kinka, Ippei Kobayashi, Katsuhiko Shibata, Masato Susukida, Kaoru Koyanagi
  • Patent number: 5294238
    Abstract: A glass substrate usable for a semiconductor device which shrinks less during a heating process. Specifically, lithium is added to the glass substrate material prior to formation. Further, the glass substrate can be thermal annealed in advance. In accordance with the present invention, it is possible to reduce substrate shrinkage even during TFT processing, by using glass material including more than 4% by weight of lithium, and further by heating the glass substrate at a temperature below the glass strain point temperature.
    Type: Grant
    Filed: March 18, 1992
    Date of Patent: March 15, 1994
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takeshi Fukada, Naoya Sakamoto
  • Patent number: 5268752
    Abstract: A red light is emitted from a red light source and a manuscript is radiated with the emitted red light and the red light reflected from the manuscript enters image sensors arranged in parallel. The red light source is synchronized with a first switching means of a first image sensor to output an output electric signal from the first image sensor. A green light is emitted, radiated reflected, and enters in the same manner as the red light. A green light source is synchronized with the first switching means to output another output electric signal from the first image sensor. A blue light is emitted and other output electric signal is outputted in the same manner as the green light. In this way a color image of the manuscript is converted into the three electric signals with respect to a first dot of the manuscript. With respect to a second dot to a 1728th dot (in the case of an A4 size manuscript), a color image of the manuscript is also converted into the three electric signals.
    Type: Grant
    Filed: July 31, 1992
    Date of Patent: December 7, 1993
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Takeshi Fukada, Masaaki Hiroki, Shunpei Yamazaki