Intermittent contact resonance atomic force microscope and process for intermittent contact resonance atomic force microscopy

Patent metadata

Field	Value
Publication number	US-9535085-B2
Application number	US-201514816438-A
Country	US
Kind code	B2
Filing date	Aug 3, 2015
Priority date	Aug 5, 2014
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

An intermittent contact atomic force microscope includes: a cantilever configured to receive a contact resonance modulation; a sample disposed proximate to the cantilever; a contact resonance modulator in communication with the cantilever and configured to provide the contact resonance modulation to the cantilever; and a scan modulator in mechanical communication with the sample to provide a scan modulation to the sample. Also disclosed is a process for performing intermittent contact atomic force microscopy, the process includes: providing a dual modulation microscope including: a cantilever configured to receive a contact resonance modulation; a sample disposed proximate to the cantilever; a contact resonance modulator in communication with the cantilever and configured to provide the contact resonance modulation to the cantilever; and a scan modulator in mechanical communication with the sample to provide a scan modulation to the sample; subjecting the cantilever to the contact resonance modulation; modulating the cantilever at a contact resonance frequency; subjecting the sample to the scan modulation; and modulating the sample at a scan modulation frequency to perform intermittent contact atomic force microscopy.

First claim

What is claimed is:

1. An intermittent contact resonance atomic force microscope comprising:
a cantilever configured to receive a contact resonance modulation comprising a contact resonance frequency;
a sample disposed proximate to the cantilever;
a contact resonance modulator in communication with the cantilever and configured to provide the contact resonance modulation to the cantilever; and
a scan modulator in communication with the sample to provide a scan modulation to the sample, the scan modulation comprising a scan modulation frequency,
wherein the contact resonance frequency is independent from the scan modulation frequency.

2. The intermittent contact resonance atomic force microscope of claim 1 , further comprising a detector to detect a deflection of the cantilever.

3. The intermittent contact resonance atomic force microscope of claim 1 , further comprising a phase sensitive detector to provide a lock frequency to the contact resonance modulator.

4. The intermittent contact resonance atomic force microscope of claim 3 , wherein the phase sensitive detector comprises a phase-locked loop (PLL) detector.

5. The intermittent contact resonance atomic force microscope of claim 1 , wherein the contact resonance modulator comprises a mechanical transducer.

6. The intermittent contact resonance atomic force microscope of claim 5 , wherein the mechanical transducer comprises a piezoelectric transducer.

7. The intermittent contact resonance atomic force microscope of claim 1 , wherein the contact resonance modulator comprises an optical transducer.

8. The intermittent contact resonance atomic force microscope of claim 7 , wherein the optical transducer comprises a laser.

9. The intermittent contact resonance atomic force microscope of claim 1 , wherein the contact resonance modulator comprises a magnetic transducer.

10. The intermittent contact resonance atomic force microscope of claim 9 , wherein the magnetic transducer comprises a magnet to provide a magnetic field to the cantilever.

11. The intermittent contact resonance atomic force microscope of claim 1 , wherein the contact resonance frequency is greater than the scan modulation frequency.

12. The intermittent contact resonance atomic force microscope of claim 11 , wherein the scan modulator provides displacement of the sample in a substantially similar direction as a displacement of the cantilever provided by the contact resonance modulator, and
the intermittent contact resonance atomic force microscope is configured to displace the sample in a two-dimensional plane that is substantially perpendicular to the contact resonance modulation of the cantilever.

13. The intermittent contact resonance atomic force microscope of claim 12 , wherein the scan modulator provides intermittent contact between the cantilever and the sample at the scan modulation frequency, and
an amplitude of displacement of the cantilever at the contact resonance frequency is less than an amplitude of displacement of the sample at the scan modulation frequency.

14. The intermittent contact resonance atomic force microscope of claim 13 , wherein the contact resonance frequency comprises an eigenmode of the cantilever.

15. The intermittent contact resonance atomic force microscope of claim 1 , wherein the intermittent contact resonance atomic force microscope provides a stiffness map of the sample, a surface topography of the sample, or a combination comprising at least one of the foregoing.

16. The intermittent contact resonance atomic force microscope of claim 15 , wherein the intermittent contact resonance atomic force microscope provides a three-dimensional stiffness of the sample.

17. The intermittent contact resonance atomic force microscope of claim 1 , wherein the intermittent contact resonance atomic force microscope provides a surface topography based on intermittent contact between the cantilever and a plurality of spots on the sample, and
the contact resonance frequency is greater than or equal to 10 kilohertz.

18. A process for performing intermittent contact resonance atomic force microscopy, the process comprising:
providing an intermittent contact resonance atomic force microscope comprising:
a cantilever configured to receive a contact resonance modulation;
a sample disposed proximate to the cantilever;
a contact resonance modulator in communication with the cantilever and configured to provide the contact resonance modulation to the cantilever; and
a scan modulator in communication with the sample to provide a scan modulation to the sample;

subjecting the cantilever to the contact resonance modulation;
modulating the cantilever at a contact resonance frequency;
subjecting the sample to the scan modulation; and
modulating the sample at a scan modulation frequency to perform intermittent contact resonance atomic force microscopy of the sample,
wherein the contact resonance frequency is independent from the scan modulation frequency.

19. The intermittent contact resonance atomic force microscope of claim 18 , further comprising detecting a deflection of the cantilever; and
producing a feedback frequency based on the deflection of the cantilever.

20. The intermittent contact resonance atomic force microscope of claim 19 , further comprising:
receiving, by a phase sensitive detector, the feedback frequency; and
providing a lock frequency to the contact resonance modulator from the phase sensitive detector, the deflection of the cantilever being phase locked to the lock frequency.

21. The intermittent contact resonance atomic force microscope of claim 20 , further comprising:
receiving, by a sample controller, the feedback frequency; and
producing, by the sample controller, the scan modulation frequency; and
providing the scan modulation frequency to the scan modulator from the sample controller.

Assignees

• Nat Inst Of Standards & Tech
• Stan Gheorghe
• Us Commerce
• Univ Maryland

Inventors

• Stan Gheorghe
• Gates Richard S

Classifications

• G01Q60/34 Primary

  Tapping mode · CPC title

• G01Q10/00 Primary

  Scanning or positioning arrangements, i.e. arrangements for actively controlling the movement or position of the probe · CPC title