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:
Dec. 12, 2000
Filed:
Jan. 26, 1998
Speedfam Co., Ltd., Tokyo, JP;
Abstract
Plasma etching method and apparatus for removing relatively thick portions from wafers by etching while measuring an actual etch quantity to thereby manufacture the wafers excellent in flatness quality on a mass-production basis. A conduit 20 of a plasma generator 2 is positioned above a relatively thick portion 111 of the wafer 110 to etch away a wafer material from the relatively thick portion 111 by ejecting a fluorine gas G. A laser beam L0 is emitted from a laser displacement meter 30 of a measuring apparatus 3 to detect an interference state between a reflected light beam L1 from the relatively thick portion 111 and a reflected light beam L2 form a reflecting plate 32 and count periodical changes of the interference state. When the count value m coincides with an integral value derived by dividing a desired etch quantity by a half wavelength of the laser beam L0, etching of the relatively thick portion 111 by the fluorine gas G is terminated.