Patents by Inventor Tetu Ohsawa

Tetu 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).

  • Substrate transfer apparatus, and method of transferring substrates
    Patent number: 5813819
    Abstract: In a vertical heat treatment apparatus, a transfer apparatus is used to transfer a wafer between a wafer carrier and a wafer boat. The transfer apparatus comprises a base unit, a fork, three non-contact type sensors, and a main controller. The base unit can move between a first position at which to transfer the wafer to and from the wafer carrier and a second position at which to transfer the wafer to and from the wafer boat. The fork can move back and forth with respect to the base unit, for supporting the wafer. The non-contact type sensors are mounted on the fork, for detecting the position of the wafer. The main controller controls the base unit and the fork in accordance with the data detected by the non-contact type sensors. Another embodiment utilizes a monitor camera in place of the sensors to monitor and display the movement of the fork relative to the wafer.
    Type: Grant
    Filed: April 7, 1997
    Date of Patent: September 29, 1998
    Assignee: Tokyo Electron Limited
    Inventors: Tetu Ohsawa, Kiyohisa Tateyama
  • Substrate transfer apparatus, and method of transferring substrates
    Patent number: 5645391
    Abstract: In a vertical heat treatment apparatus, a transfer apparatus is used to transfer a wafer between a wafer carrier and a wafer boat. The transfer apparatus comprises a base unit, a fork, three non-contact type sensors, and a main controller. The base unit can move between a first position at which to transfer the wafer to and from the wafer carrier and a second position at which to transfer the wafer to and from the wafer boat. The fork can move back and forth with respect to the base unit, for supporting the wafer. The non-contact type sensors are mounted on the fork, for detecting the position of the wafer. The main controller controls the base unit and the fork in accordance with the data detected by the non-contact type sensors.
    Type: Grant
    Filed: May 31, 1995
    Date of Patent: July 8, 1997
    Assignees: Tokyo Electron Limited, Tokyo Electron Tohoku Limited
    Inventors: Tetu Ohsawa, Kiyohisa Tateyama
  • Method of heat treating semiconductor wafers by varying the pressure and temperature
    Patent number: 5296412
    Abstract: A wafer boat on which semiconductor wafers are placed is inserted into a process tube, and a process gas is supplied into the process tube to perform heat treating. In this case, prior to the heat treating, the process tube is evacuated to have a pressure lower than a pressure in the heat treating while a temperature in the process tube is kept to be higher than a temperature in the heat treating. After the heat treating is performed, the process tube is purged with an N.sub.2 gas.
    Type: Grant
    Filed: June 25, 1993
    Date of Patent: March 22, 1994
    Assignees: Tokyo Electron Limited, Tokyo Electron Tohoku Limited
    Inventor: Tetu Ohsawa
  • Wafer boat or rack
    Patent number: D366868
    Type: Grant
    Filed: September 29, 1993
    Date of Patent: February 6, 1996
    Assignees: Tokyo Electron Kabushiki Kaisha, Tokyo Electron Tohoku Kabushiki Kaisha
    Inventor: Tetu Ohsawa