Patents by Inventor Tomotsugu Ohashi

Tomotsugu Ohashi 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).

  • Method of etching backside Si substrate of SOI substrate to expose SiOlayer using fluonitric acid
    Patent number: 9240505
    Abstract: A method of etching capable of rapidly and flatly performing wet etching on a Si substrate using fluonitric acid represented by HF(a)HNO3(b)H2O(c) (where the unit of a, b and c is wt % and a+b+c=100). The etching rate of an SiO2 layer with the highly concentrated fluonitric acid is significantly lowered by the appropriate selection of its composition as compared with the etching rate of the Si substrate, and etch the Si substrate until the SiO2 layer is exposed. In this way, it is possible to rapidly etch the Si substrate and significantly enhance the flatness of the etched surface.
    Type: Grant
    Filed: October 28, 2011
    Date of Patent: January 19, 2016
    Assignee: TOHOKU UNIVERSITY
    Inventors: Tadahiro Ohmi, Tomotsugu Ohashi, Kazuhiro Yoshikawa, Tatsuro Yoshida, Teppei Uchimura, Kazuki Soeda, Shigetoshi Sugawa
  • Ultra high-speed wet etching apparatus
    Patent number: 8728338
    Abstract: There is provided with an etching method using an etching apparatus. Four arms can be positioned in a direction substantially from a center of the stage toward a peripheral portion with an angle difference of about 90°. Etchant is supplied to a first position nearest to the center of the object which is rotating, from a first etchant supply nozzle placed on a first arm. Etchant is further supplied to a second position second nearest to the center of the object, from a second etchant supply nozzle placed on a second arm. The second arm is substantially symmetrically positioned with respect to the first arm and the second arm has an angle difference of about 180° with respect to the first arm.
    Type: Grant
    Filed: May 6, 2013
    Date of Patent: May 20, 2014
    Assignee: National University Corporation Tohoku University
    Inventors: Tadahiro Ohmi, Tomotsugu Ohashi, Kazuhiro Yoshikawa, Tetsuro Yoshida, Teppei Uchimura, Kazuki Soeda
  • METHOD OF ETCHING OF SOI SUBSTRATE, AND BACK-ILLUMINATED PHOTOELECTRIC CONVERSION MODULE ON SOI SUBSTRATE AND PROCESS OF MANUFACTURE THEREOF
    Publication number: 20130320477
    Abstract: A method of etching capable of rapidly and flatly performing wet etching on a Si substrate using fluonitric acid represented by HF(a)HNO3(b)H2O(c) (where the unit of a, b and c is wt % and a+b+c=100). The etching rate of an SiO2 layer with the highly concentrated fluonitric acid is significantly lowered by the appropriate selection of its composition as compared with the etching rate of the Si substrate, and etch the Si substrate until the SiO2 layer is exposed. In this way, it is possible to rapidly etch the Si substrate and significantly enhance the flatness of the etched surface.
    Type: Application
    Filed: October 28, 2011
    Publication date: December 5, 2013
    Applicant: TOHOKU UNIVERSITY
    Inventors: Tadahiro Ohmi, Tomotsugu Ohashi, Kazuhiro Yoshikawa, Tatsuro Yoshida, Teppei Uchimura, Kazuki Soeda, Shigetoshi Sugawa
  • ELECTRODIALYZER
    Publication number: 20120031763
    Abstract: An object of this invention is to provide an electrodialyzer which is effective in saving electric power. According to this invention, there is provided an electrodialyzer which electrically dialyzes water to be processed while a voltage causing substantially no current to flow is applied between an anode and a cathode.
    Type: Application
    Filed: April 20, 2010
    Publication date: February 9, 2012
    Inventors: Tadahiro Ohmi, Tetsuya Goto, Tomotsugu Ohashi, Keita Fushimi, Takashi Imaoka