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:
Oct. 23, 1990
Filed:
Jan. 18, 1989
Toshihiko Yamauchi, Yokohama, JP;
Nobuyuki Akiyama, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
The present invention resides in a method and apparatus for detecting a foreign particle, wherein an ultraviolet light beam is radiated in the form of a spot to a sample having a protective film formed on a circuit pattern or a wiring pattern; the spot and the sample are scanned relative to each other; the ultraviolet light is absorbed by the protective film; diffracted light produced from a foreign particle present on the protective film is condensed by an integrating sphere; the thus-condensed light is sensed by an optoelectro transducer to convert it into an electric signal; and the foreign particle present on the protective film formed on the circuit pattern or the wiring pattern is detected on the basis of the electric signal provided from the optoelectro transducer.