Patents by Inventor Akihisa Shimomura

Akihisa Shimomura 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).

  • Publication number: 20030215973
    Abstract: Island-like semiconductor films and markers are formed prior to laser irradiation. Markers are used as positional references so as not to perform laser irradiation all over the semiconductor within a substrate surface, but to perform a minimum crystallization on at least indispensable portion. Since the time required for laser crystallization can be reduced, it is possible to increase the substrate processing speed. By applying the above-described constitution to a conventional SLS method, a means for solving such problem in the conventional SLS method that the substrate processing efficiency is insufficient, is provided.
    Type: Application
    Filed: December 10, 2002
    Publication date: November 20, 2003
    Applicant: Semiconductor Energy
    Inventors: Shunpei Yamazaki, Akihisa Shimomura, Hisashi Ohtani, Masaaki Hiroki, Koichiro Tanaka, Aiko Shiga, Mai Akiba, Kenji Kasahara
  • Publication number: 20030183875
    Abstract: It is a problem to provide a semiconductor device production system using a laser crystallization method capable of preventing grain boundaries from forming in a TFT channel region and further preventing conspicuous lowering in TFT mobility due to grain boundaries, on-current decrease or off-current increase. An insulation film is formed on a substrate, and a semiconductor film is formed on the insulation film. Due to this, preferentially formed is a region in the semiconductor film to be concentratedly applied by stress during crystallization with laser light. Specifically, a stripe-formed or rectangular concavo-convex is formed on the semiconductor film. Continuous-oscillation laser light is irradiated along the striped concavo-convex or along a direction of a longer or shorter axis of rectangle.
    Type: Application
    Filed: December 27, 2002
    Publication date: October 2, 2003
    Inventors: Atsuo Isobe, Koji Dairiki, Hiroshi Shibata, Chiho Kokubo, Tatsuya Arao, Masahiko Hayakawa, Hidekazu Miyairi, Akihisa Shimomura, Koichiro Tanaka, Shunpei Yamazaki, Mai Akiba
  • Publication number: 20030180992
    Abstract: A laser beam irradiation method that achieves uniform crystallization, even if a film thickness of an a-Si film or the like fluctuates, is provided. The present invention provides a laser beam irradiation method in which a non-single crystal semiconductor film is formed on a substrate having an insulating surface and a laser beam having a wavelength longer than 350 nm is irradiated to the non-single crystal semiconductor film, thus crystallizing the non-single crystal silicon film. The non-single crystal semiconductor film has a film thickness distribution within the surface of the substrate, and a differential coefficient of a laser beam absorptivity with respect to the film thickness of the non-single crystal semiconductor film is positive.
    Type: Application
    Filed: December 20, 2002
    Publication date: September 25, 2003
    Inventors: Akihisa Shimomura, Kenji Kasahara, Aiko Shiga, Hidekazu Miyairi, Koichiro Tanaka, Koji Dairiki
  • Publication number: 20030148594
    Abstract: To provide a continuous-oscillating laser apparatus capable of improving the efficiency of substrate treatment, a method of irradiating a laser beam, and a method of manufacturing a semiconductor device using the laser apparatus. Of the entire semiconductor film, a portion that needs to be left on the substrate after patterning is identified according to a mask. Then, a portion to be scanned by respective lasers are defined, so that a laser beam is irradiated twice in different scanning directions to a portion to be obtained at least through patterning and beam spots are impinged upon the scanned portion, thereby partially crystallizing the semiconductor film. In other words, in the invention, it is arranged in such a manner that a laser beam is not irradiated by scanning a laser beam across the entire semiconductor film but by scanning a laser beam twice at least to the absolutely necessary portion.
    Type: Application
    Filed: November 7, 2002
    Publication date: August 7, 2003
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Hisashi Ohtani, Masaaki Hiroki, Koichiro Tanaka, Aiko Shiga, Akihisa Shimomura, Mai Akiba
  • Publication number: 20030141521
    Abstract: An objective is to provide a method of manufacturing a semiconductor device, and a semiconductor device manufactured by using the manufacturing method, in which a laser crystallization method is used that is capable of preventing the formation of grain boundaries in TFT channel formation regions, and is capable of preventing conspicuous drops in TFT mobility, reduction in the ON current, and increases in the OFF current, all due to grain boundaries. Depressions and projections with stripe shape or rectangular shape are formed. Continuous wave laser light is then irradiated to a semiconductor film formed on an insulating film along the depressions and projections with stripe shape of the insulating film, or along a longitudinal axis direction or a transverse axis direction of the rectangular shape. Note that although it is most preferable to use continuous wave laser light at this point, pulse wave laser light may also be used.
    Type: Application
    Filed: January 28, 2003
    Publication date: July 31, 2003
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Shunpei Yamazaki, Chiho Kokubo, Koichiro Tanaka, Akihisa Shimomura, Tatsuya Arao, Hidekazu Miyairi, Mai Akiba
  • Publication number: 20030141505
    Abstract: To provide a semiconductor device composed of a semiconductor element or a group of semiconductor elements, in which a crystalline semiconductor film having as few grain boundaries as possible in a channel formation region is formed on an insulating surface, which can operate at high speed, which have high current drive performance, and which are less fluctuated between elements.
    Type: Application
    Filed: January 28, 2003
    Publication date: July 31, 2003
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Atsuo Isobe, Shunpei Yamazaki, Chiho Kokubo, Koichiro Tanaka, Akihisa Shimomura, Tatsuya Arao, Hidekazu Miyairi
  • Publication number: 20030089690
    Abstract: Continuous wave laser apparatus with enhanced processing efficiency is provided as well as a method of manufacturing a semiconductor device using the laser apparatus. The laser apparatus has: a laser oscillator; a unit for rotating a process object; a unit for moving the center of the rotation along a straight line; and an optical system for processing laser light that is outputted from the laser oscillator to irradiate with the laser light a certain region within the moving range of the process object. The laser apparatus is characterized in that the certain region is on a line extended from the straight line and that the position at which the certain region overlaps the process object is moved by rotating the process object while moving the center of the rotation along the straight line.
    Type: Application
    Filed: September 9, 2002
    Publication date: May 15, 2003
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Koichiro Tanaka, Hidekazu Miyairi, Aiko Shiga, Akihisa Shimomura, Mai Akiba
  • Publication number: 20030086182
    Abstract: The present invention is characterized in that by laser beam being slantly incident to the convex lens, an aberration such as astigmatism or the like is occurred, and the shape of the laser beam is made linear on the irradiation surface or in its neighborhood. Since the present invention has a very simple configuration, the optical adjustment is easier, and the device becomes compact in size. Furthermore, since the beam is slantly incident with respect to the irradiated body, the return beam can be prevented.
    Type: Application
    Filed: September 24, 2002
    Publication date: May 8, 2003
    Inventors: Koichiro Tanaka, Hidekazu Miyairi, Aiko Shiga, Akihisa Shimomura, Atsuo Isobe
  • Publication number: 20030080100
    Abstract: To provide a continuous oscillation laser apparatus, and a manufacturing method of a semiconductor device using the continuous oscillation laser apparatus, which can enhance processing efficiency. A laser apparatus according to the present invention includes: a laser oscillation apparatus; a unit for rotating an object to be processed; a unit for moving the object to be processed toward a center of the rotation or toward an outside from the center; and an optical system for processing a laser light outputted from the laser oscillation apparatus and irradiating the processed laser light to a definite region in a moving range of the object to be processed, in which, while the object to be processed is rotated, the object to be processed is moved toward the center of the rotation or toward the outside from the center to move a position where the definite region and the object to be processed overlap.
    Type: Application
    Filed: September 6, 2002
    Publication date: May 1, 2003
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Koichiro Tanaka, Hidekazu Miyairi, Aiko Shiga, Akihisa Shimomura