Filing Information

Inventor(s)	Chanmin Su · Kenneth L. Babcock · Lin Huang ·
Assignee(s)	Veeco Instruments Inc. ·  View assignee updates
Attorney/Agent(s)	Boyle Fredrickson Newholm Stein & Gratz S.C. ·
Primary Examiner	Helen Kwok ·
Application Number	US10189108
Filing date	07/02/2002
Issue date	09/20/2005
Predicted expiration date	07/02/2022
U.S. Classifications	731/5  ·
International Classifications	--
Kind Code	B1
International Classifications	73105 · 73579 · 73649 · 73650 · 250306 · 250307 ·

Patent Family

Abstract

An apparatus and method of operating a probe-based instrument in a torsional mode. The method includes providing a probe having a cantilever defining a longitudinal axis and supporting a tip. In operation, the method torsionally oscillates the probe generally about the longitudinal axis at a resonance. In addition, the method changes a separation distance between the tip and a surface of a sample so the tip interacts with the surface during data acquisition. By detecting a change in the torsional oscillation of the cantilever in response to the interaction between the tip and the surface, forces, including shear forces and shear force gradients, between the tip and the surface can be measured to determine sub-nanometer features.

Independent Claims | See all claims (65)

1. 1. A method of operating a probe-based instrument, the method comprising the steps of: providing a probe including a cantilever and a tip, the cantilever having a longitudinal axis; torsionally oscillating the probe generally about the axis at a resonance; and wherein said torsionally oscillating step is performed using an asymmetric transducer.
2. 29. A method of measuring a property of a sample, the method comprising the steps of: driving a probe having a tip at a torsional resonance of the probe; changing a separation between the tip and the sample so as to cause interaction between the tip and the sample; detecting the interaction, wherein the interaction is indicative of one of a group including a shear force and a force gradient; and wherein said driving step is perfomed using an asymmetric transducer, and wherein the asymmetric transducer includes at least two sources of ultrasonic energy generally mounted on opposite sides of the tip and are driven by respective signals having at least one different property.
3. 36. A probe-based instrument comprising: a probe assembly including a base and a probe, said probe having a cantilever extending from said base and a tip supported by said cantilever; a drive coupled to said probe assembly and configured to actuate said probe into torsional oscillation; and wherein said drive is asymmetric, and wherein said asymmetric drive includes at least two sources of ultrasonic energy generally mounted on opposite sides of the tip and are driven by different signals.
4. 56. A drive for a probe-based instrument, the drive comprising: an actuator coupled to a probe assembly of the instrument, said probe assembly including a probe having a tip, and said actuator driving said probe at a torsional resonance thereof; and wherein said actuator includes a plurality of piezoelectric elements that are generally mounted on opposite sides of the tip and are driven by different signals.
5. 57. A probe-based instrument comprising: a probe assembly including a probe having a cantilever and a tip supported by said cantilever; an actuator coupled to said probe assembly; a signal generator that transmits a modulated signal to said actuator to drive said probe into both flexural oscillation and torsional oscillation; and wherein said acutator includes a pair of piezoelectric elements mounted substantially on opposite sides of the tip, the piezoelectric elements driven by oscillating drive signals substantially 180° out of phase.
6. 63. An apparatus to control and maintain generally constant probe/sample interaction using torsional resonance, comprising: a probe; a plurality of piezoelectric elements coupled to the probe and driven by independent drive signals having at least one different property so as to excite a torsional resonance of the probe; a displacement detection system to generally simultaneously sense flexural and torsional movement of said probe; an xyz actuator to provide relative motion between said probe and a sample in three generally orthogonal directions; and a feedback system coupled to said detection system and said actuator to maintain constant probe sample interaction in response to detecting a change in said torsional resonance of said probe.