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:
Dec. 28, 1999
Filed:
Dec. 03, 1997
Virgil B Elings, Santa Barbara, CA (US);
Sergei Magonov, Santa Barbara, CA (US);
Digital Instruments, Santa Barbara, CA (US);
Abstract
The oscillation parameters of a probe of an atomic force microscope (AFM) typically vary over time. This variation can cause problems during either 1) scanning or measurement functions in which the probe's operative state is one in which oscillatory measurements are taken or 2) the process of bringing the tip to the sample to begin measurement, commonly referred to as engaging the probe, in which the probe's operative state is one in which the probe is about to move into its measuring position. These problems can be eliminated during either process by measuring changes in a parameter or parameters of probe oscillation, determining what changes are not due to probe-sample interaction, and correcting the oscillation parameters accordingly. This may be accomplished in two ways, the first with the probe out of intermittent contact with the sample, and the second during scanning. The first comprises placing the probe in a reference or free oscillation state in which the probe tip oscillates at a free oscillation amplitude A.sub.o, measuring A.sub.o and adjusting it if necessary, and then returning the probe to its operative state. The probe can be placed in its reference state by varying the spacing between the probe and the sample, by altering probe drive parameters, or by any other suitable technique. The second comprises measuring the phase of the probe oscillation during scanning and adjusting the phase to a desired range.