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:
Jul. 15, 2014
Filed:
Oct. 10, 2012
Fei Company, Hillsboro, OR (US);
Lynwood W. Swanson, McMinnville, OR (US);
Gregory A. Schwind, Portland, OR (US);
Sean Kellogg, Portland, OR (US);
Kun Liu, Portland, OR (US);
FEI Company, Hillsboro, OR (US);
Abstract
The state of an emitter can be determined by measurements of how the current changes with the extraction voltage. A field factor β function is determined by series of relatively simple measurements of charged particles emitted at different conditions. The field factor can then be used to determine derived characteristics of the emission that, in the prior art, were difficult to determine without removing the source from the focusing column and mounting it in a specialized apparatus. The relations are determined by the source configuration and have been found to be independent of the emitter shape, and so emission character can be determined as the emitter shape changes over time, without having to determine the emitter shape and without having to redefine the relation between the field factor and the series of relatively simple measurements, and the relationships between the field factor and other emission parameters.