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:
Sep. 26, 1989
Filed:
Jul. 12, 1988
Canon Kabushiki Kaisha, , US;
Abstract
A plate-like article holding device particularly suitably usable in an exposure apparatus for printing a pattern of a reticle or mask on a semiconductor wafer, as a wafer holding device for holding the wafer at a pattern printing station, is disclosed. In an embodiment, the holding device includes a wafer chuck having a wafer attracting surface and a plurality of throughbores formed in relation to the attracting surface. Also, the device includes a plurality of support pillars provided in relation to the throughbores, respectively, and having end faces effective to support a wafer by attraction. There is provided a driving mechanism for moving the wafer chuck in a direction substantially perpendicular to the wafer attracting surface of the chuck so as to allow that the supporting end faces of the support pillars project outwardly beyond the wafer attracting surface of the wafer chuck or, alternatively, they are accommodated within the wafer chuck. A wafer having been conveyed to the device is first attracted to and supported by the supporting pillars as they are projected from the wafer attracting surface of the chuck. Thereafter, the wafer chuck is moved by the driving mechanism so that the wafer attracting surface thereof contacts the wafer.