The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 31, 1998
Filed:
Dec. 12, 1994
Tomoaki Muramatsu, Kawasaki, JP;
Takashi Yoshida, Kawasaki, JP;
Fujitsu Limited, Kanagwa, JP;
Abstract
A polishing apparatus comprises a pressure container having a first opening at its bottom and being rotatable about an axis perpendicular to a plane of the first opening; a wafer support coupled elastically to the first opening, sealing the first opening hermetically and having a wafer supporting surface; and a lower surface plate disposed underneath the wafer supporting surface and having a polishing surface approximately parallel to the wafer supporting surface. The wafer support may be provided with flatness adjusting means for selectively applying a larger pressure on a region of the wafer held on the wafer supporting surface than a pressure on other region. The flatness adjusting means may comprise a plurality of pressing pins, or may comprise a hollow within the wafer support, a surface plate having elasticity and sealing the hollow, and means for applying pressure to the hollow. Wafer can be polished under uniform pressure applied on the back surface. Flatness of the wafer can be improved.