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:
May. 26, 1992
Filed:
Jun. 19, 1991
Kazumitsu Nakamura, Katsuta, JP;
Shinichi Kato, Mito, JP;
Yoshio Sakitani, Ooarai, JP;
Yoshihisa Minamikawa, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An electron beam measuring apparatus for measuring size of pattern on surface of a specimen comprising, an electron gun, an electron lens for focusing the electron beam from the electron gun on the specimen surface, a deflector for deflecting the electron beam, a spot control means for forming a flat edge portion in the electron beam spot, a rotation coil for rotating the electron beam so that the flat portion of the electron beam spot becomes to be perpendicular to the scanning direction of the electron beam, a detecting means for detecting secondary electrons reflected from the specimen surface, and a computer for calculating the size of the pattern based on the secondary electrons from the detecting means. As the flat portion of the electron beam spot is perpendicular to the scanning direction, the size of pattern is measured with high accuracy.