Patents by Inventor Tomio Katala

Tomio Katala 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: 20020006680
    Abstract: In chucking a wafer to an electrostatic chuck type hot plate mounted in a semiconductor manufacturing apparatus, the chucking force is successively applied from the central portion toward the outer peripheral portion of the wafer. Therefore, the chuck electrode is divided in its radial direction into at least two electrode portions comprising an inner circumferential electrode portion and an outer circumferential electrode portion, and the chuck voltage is applied successively from the inner circumferential electrode portion toward the outer circumferential electrode portion. The chucking force is applied first to the central portion of the wafer so as to elevate the wafer temperature. In this step, the chucking force in the outer peripheral portion of the wafer is weak so as to permit the wafer to be thermally expanded smoothly. As a result, the stress within the wafer is low so as to prevent the wafer from being broken.
    Type: Application
    Filed: July 10, 2001
    Publication date: January 17, 2002
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tomio Katala, Junichi Wada