Veeco Instruments Inc.

Digital Instruments

Sergei Magonov

Chanmin Su

Virgil B Elings

Dynamic nanomechanical analysis of a sample is performed by using a cantilever probe that interacts with the sample using a force applied across a wide range of frequencies that includes frequencies greater than 300 Hz. The motion of the cantilever probe is detected in response to the applied force over the range of frequencies and analyzed over at least a portion of the wide range of frequencies to determine a mechanical response of the sample, preferably including quality factor and modulus of the sample. The analysis of the motion of the cantilever probe is preferably performed in terms of amplitude, phase, and frequency of both the probe and the sample and preferably, where the applied force is analyzed to determine both a real and an imaginary modulus of a mechanical response of the sample. Preferably, the force is applied so as to produce a minimum of phase and amplitude response variation in the absence of the sample. Furthermore the motion of the cantilever can be flexural or torsional and combinations thereof.

System for wide frequency dynamic nanomechanical analysis

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.

Growing community of inventors

Santa Barbara, CA, United States of America

Sergei Magonov