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:
Jun. 09, 2009
Filed:
Dec. 05, 2006
Marinus Johannes Van Der Zande, Roosendaal, NL;
Christiaan Kok, Eindhoven, NL;
Bernd Rieger, Delft, NL;
Marinus Johannes van der Zande, Roosendaal, NL;
Christiaan Kok, Eindhoven, NL;
Bernd Rieger, Delft, NL;
FEI Company, Hillsboro, OR (US);
Abstract
A lens of particle-optical apparatus, such as the objective lens, suffers from aberrations. As is already known since decades Ronchigrams can be used to determine these aberrations of particle-optical lenses. Such methods rely e.g. on the determination of the 2derivative of the aberration function on the basis of local magnification in one or a set of Ronchigrams. Being dependent on the 2derivative the mathematics of these methods allow only (infinitesimal) small shifts between the Ronchigrams. However, this implies that e.g. the spatial quantization noise of the camera recording the Ronchigrams results in a large error. These conflicting requirements limit the accuracy and thus the usefulness of the known methods. The invention describes a set of algorithms which result in an improved method to quantify the lens aberration coefficients using a set of Ronchigrams.