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. 24, 2011
Filed:
Nov. 20, 2007
Hiroyuki Ito, Hitachinaka, JP;
Yuko Sasaki, Mito, JP;
Tohru Ishitani, Hitachinaka, JP;
Yoshinori Nakayama, Sayama, JP;
Hiroyuki Ito, Hitachinaka, JP;
Yuko Sasaki, Mito, JP;
Tohru Ishitani, Hitachinaka, JP;
Yoshinori Nakayama, Sayama, JP;
Hitachi High-Technologies Corporation, Tokyo, JP;
Abstract
The present invention relates to an orbit correction method for a charged particle beam, and aims to solve problems inherent in conventional aberration correction systems and to provide a low-cost, high-precision, high-resolution optical converging system for a charged particle beam. To this end, employed is a configuration in which a beam orbit is limited in ring zone form to form a distribution of electromagnetic field converging toward the center of a beam orbit axis. Consequently, a nonlinear action outwardly augmented, typified by spherical aberration of an electron lens, can be cancelled out. Specifically, this effect can be achieved by an electron disposed on the axis and subjected to a voltage to facilitate the occurrence of electrostatic focusing. For a magnetic field, this effect can be achieved by forming a coil radially distributed-wound on a surface equiangularly divided in the direction of rotation to control convergence of a magnetic flux density.