Patents by Inventor Akihiro Ohsawa

Akihiro Ohsawa 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: 20070009010
    Abstract: A non-contact wafer temperature measuring apparatus by which a wafer temperature can be measured with accuracy in situ even in a low temperature process. The wafer temperature measuring apparatus for measuring a wafer temperature based on reflected light of light applied to a wafer as a target of temperature measurement includes: a light source unit for generating light containing a P-polarized component having a wavelength not larger than 400 nm and applying the light to the wafer; a light receiving unit for receiving the light reflected by the wafer and detecting at least intensity of the P-polarized component having the wavelength not larger than 400 nm; and a signal processing unit for calculating a temperature of the target of temperature measurement at least based on the intensity of the P-polarized component having the wavelength not larger than 400 nm detected by the light receiving unit.
    Type: Application
    Filed: June 22, 2006
    Publication date: January 11, 2007
    Inventors: Koji Shio, Hideyuki Wakai, Akihiro Ohsawa, Hironori Akiba
  • Publication number: 20060034346
    Abstract: A film-like temperature sensor for more accurately measuring the temperatures at plural locations on the surface of a semiconductor wafer comprises a base film made of an insulating material; plural thin-film thermal elements for sensing temperature; plural thin-film leads, connected to the thermal elements; and plural thin-film terminals connected to the ends of the leads. The thermal elements, leads, and terminals are integrally formed either on the surface or in the thickness of the base film. The base film has a flat shape like a paddle, and comprises a head portion to be attached to the surface of a semiconductor wafer, and a strip-shaped tail portion extending outwardly of the semiconductor wafer. The plural thermal elements are arranged on the head portion in the form of either a concentric circle, spiral, matrix, or raster, and the plural terminals are arranged on the tail portion.
    Type: Application
    Filed: August 12, 2005
    Publication date: February 16, 2006
    Applicant: KOMATSU ELECTRONICS, INC
    Inventors: Katsuo Saio, Akihiro Ohsawa
  • Publication number: 20030231694
    Abstract: At the time when a temperature of a semiconductor wafer or the like is measured by light without contacting to it, its temperature is measured with high precision without suffering from an influence of changes in temperature of a light source, an influence of a bent degree or the like of an optical fiber or an influence of a displacement of an optical system such as a lens or the like. Light output from the light source is irradiated to the semiconductor wafer through an optical fiber for irradiated light. The light reflected from the semiconductor wafer is output as reflected light through an optical fiber for the reflected light. An optical fiber for reference light having substantially the same route as those of the optical fiber for irradiated light and the optical fiber for reflected light is disposed. The light output from the light source is output as the reference light through the optical fiber for reference light without being irradiated to or reflected from the semiconductor wafer.
    Type: Application
    Filed: March 24, 2003
    Publication date: December 18, 2003
    Inventor: Akihiro Ohsawa
  • Patent number: 6626236
    Abstract: Object of the present invention is to provide uniform heat distribution to a substrate undergoing heat treatment on top of a heat exchange plate. A heat exchange plate 1 is a flat, circular receptacle, has a cooling liquid inflow opening 11 on one end and outflow opening 13 on the other end, and cooling liquid flows on the inside. The surface of the plate 1 is divided, for example, into four zones having different heat capacities and heat transfer characteristics, and an independently controllable foil heater 21A, 23A, 25A, 27A is attached to each zone. Heater 21A covers a zone, which circumferentially surrounds a substrate placed on top of a plate, heater 23A covers a zone directly beneath a substrate, heater 25A covers a zone of the vicinity of the outflow opening 13, and heater 27A covers a zone of the vicinity of the inflow opening 11. Temperature sensors 31-33 are disposed on the inside of a plate at four locations of a second zone, which are apt to receive the affects of the first to fourth zones.
    Type: Grant
    Filed: March 20, 2000
    Date of Patent: September 30, 2003
    Assignee: Komatsu Ltd.
    Inventors: Kenichi Bandoh, Akihiro Ohsawa, Mikio Minonishi