Patents Assigned to Sumico Corporation
  • Publication number: 20200185263
    Abstract: Provided is a susceptor which makes it possible to increase the circumferential flatness uniformity of an epitaxial layer of an epitaxial silicon wafer. A susceptor 100 is provided with a concave counterbore portion on which a silicon wafer W is placed, and the radial distance L between the center of the susceptor and an opening edge of the counterbore portion varies at 90° periods in the circumferential direction. Meanwhile, when the angle at which the radial distance L is minimum is 0°, the radial distance L is a minimum value L1 at 90°, 180°, and 270°; and the radial distance L is a maximum value L2 at 45°, 135°, 225°, and 315°. Accordingly, the pocket width Lp also varies in conformance with the variations of the radial distance L. The opening edge 110C describes four elliptical arcs being convex radially outward when the susceptor 100 is viewed from above.
    Type: Application
    Filed: August 31, 2017
    Publication date: June 11, 2020
    Applicant: SUMICO CORPORATION
    Inventor: Kazuhiro Narahara
  • Patent number: 8728942
    Abstract: Mirror-polishing a front surface of a silicon wafer using polishing liquid composed of an abrasive grain-free alkaline solution including water-soluble polymers simplifies a polishing process, thus leading to an increase in productivity and a reduction in cost, and reduces the density of LPDs attributable to processing and occurring in the front surface of a mirror-polished wafer, thus improving the surface roughness of the wafer front surface.
    Type: Grant
    Filed: August 20, 2010
    Date of Patent: May 20, 2014
    Assignee: Sumico Corporation
    Inventors: Shinichi Ogata, Kazushige Takaishi, Hironori Nishimura, Shigeru Okuuchi, Shunsuke Mikuriya, Yuichi Nakayoshi