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. 12, 1987
Filed:
Apr. 01, 1985
Lawrence F Bacchetti, Belmont, MA (US);
David M Walker, Westford, MA (US);
Donald O Smith, Lexington, MA (US);
Control Data Corporation, Minneapolis, MN (US);
Abstract
A method and apparatus for in-situ cleaning of charged particle beam optical systems such as electron microscopes, electron beam lithography systems, ion beam microscopes or lithography systems, through the use of a specially introduced plasma forming gas such as hydrogen that is excited by applying a high voltage, high frequency excitation potential between various optical elements of the electron beam optical column. Alternately, specially constructed separate plasma forming electrodes can be built into the electron beam optical system for this purpose. During the cleaning operation the plasma reacts chemically with the contaminants previously formed on the surface of the electron beam column optical elements to form gaseous reactants which then are pumped out of the electron beam column system.