Patents by Inventor Moritaka Iwasa

Moritaka Iwasa 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).

  • Silicon single crystal substrate and manufacture thereof
    Patent number: 8241423
    Abstract: A semiconductor wafer for an epitaxial growth is disclosed comprising: a main face on which a vapor phase epitaxial layer grows; a back face provided on an opposite side of the wafer; a main chamfered part along a circumferential edge where the main face and a side face of the wafer meet; and a back chamfered part along a circumferential edge where the back face and the side face meet is provided. After a CVD layer formation process is conducted to form a layer at least on the back face and the back chamfered part, a machining process is conducted on the main face to remove a CVD layer at least partially formed thereon so as to polish the main face to a mirror finished surface with a maximum height of profile (Rz) not exceeding 0.3 ?m.
    Type: Grant
    Filed: September 28, 2007
    Date of Patent: August 14, 2012
    Assignee: Sumco Techxiv Corporation
    Inventors: Eisyun Ikubo, Naoto Hirano, Moritaka Iwasa
  • SILICON SINGLE CRYSTAL SUBSTRATE AND MANUFACTURE THEREOF
    Publication number: 20080224270
    Abstract: A semiconductor wafer for an epitaxial growth is disclosed comprising: a main face on which a vapor phase epitaxial layer grows; a back face provided on an opposite side of the wafer; a main chamfered part along a circumferential edge where the main face and a side face of the wafer meet; and a back chamfered part along a circumferential edge where the back face and the side face meet is provided. After a CVD layer formation process is conducted to form a layer at least on the back face and the back chamfered part, a machining process is conducted on the main face to remove a CVD layer at least partially formed thereon so as to polish the main face to a mirror finished surface with a maximum height of profile (Rz) not exceeding 0.3 ?m.
    Type: Application
    Filed: September 28, 2007
    Publication date: September 18, 2008
    Applicant: SUMCO TECHXIV CORPORATION
    Inventors: Eisyun Ikubo, Naoto Hirano, Moritaka Iwasa