Atomic force microscope

• US 6,862,923 B2
• Filed: 03/30/2001
• Issued: 03/08/2005
• Est. Priority Date: 03/31/2000
• Status: Expired due to Term

• Current Assignee: Institut Curie
• Original Assignee: Centre National De La Recherche Scientifique
• Inventors: Silberzan, Pascal, Buguin, Axel
• Primary Examiner(s): Cygan, Michael
• Application Number:
  US10/240,242
• Publication Number:
  US 20030167830A1
• Time in Patent Office: 1,439 Days
• Field of Search: 731/05, 250/306, 324/244
• US Class Current: 73/105
• CPC Class Codes: B82Y 35/00 Methods or apparatus for measurement or analysis of nanostructures
• CPC Class Codes: G01Q 60/32 AC mode
• CPC Class Codes: Y10S 977/863 Atomic force probe

Abstract

This atomic force microscope has a probe for surface analysis of a sample (E), comprising a support body and an elastically deformable strip linked to the body, the strip being provided with a tip designed to come into contact with the sample (E) to be analysed. The microscope also has a mechanism for relative displacement of the analysis probe with respect to the surface of the sample (E), a detector for determining the position of the strip, and elements for vibrating the strip. These means for vibrating the strip include elements for conduction of electricity along a continuous path forming a loop, an alternating-current generator, and a magnetic-field source designed to set up a magnetic field ({right arrow over (B)}) in the region of the strip of the analysis probe.

Claims

1. Atomic force microscope, comprising

a probe (12) for surface analysis of a sample (E), comprising a support body (20) and an elastically deformable strip (22) linked to the body (20), the strip being provided with a tip (24) designed to come into contact with the sample (E) to be analysed;

a mechanism (16) for relative displacement of the analysis probe (12) with respect to the surface of the sample (E);

a detector (50, 52) for determining the position of the strip (22); and

means for vibrating the strip (22), said means for vibrating the strip comprising;

on the strip (22), means (26A, 26B) for conduction of electricity along a continuous path forming a loop (27), which electrical-conduction means (26A, 26B) are secured to the strip (22), the support body (20) being provided with two divided conductive sections (30A, 30B) extending the loop (27),

an alternating-current generator (34) connected to the divided conductive sections (30A, 302) of the analysis probe (12), and

a magnetic-field source (18) designed to set up a substantially homogeneous magnetic field ({circle around (B)}) in the region of the strip (22) of the analysis probe (12), wherein the loop (27) has a single turn which is open in the region of the support body (20).

2. Microscope according to claim 1, wherein the detector has means (76) for analysis of currents induced by the magnetic field ({circle around (B)}) in the loop (27).

3. Microscope according to claim 1, wherein the strip (22) has two branches (26A, 26B) which converge towards each other from divided roots for linkage to the support body (20) as far as a junction bend which carries the tip (24), and wherein the continuous path forming the loop (27) extends along the length of the two branches (26A, 26B).

4. Microscope according to claim 1, wherein the electrical-conduction means have a conductive coating which is formed on one face of the strip (22) and extends over the support body (20) to form the two divided conductive sections (30A, 302), the latter being separated by a coating-free area (32) of the body.

5. Microscope according to claim 1, wherein the magnetic-field source (18) is designed to set up a permanent magnetic field ({circle around (B)}) in the region of the strip (22).

6. Microscope according to claim 1, wherein the alternating-current generator (34) has means for controlling the frequency of the current, which are designed to bring the latter to a frequency substantially equal to the resonant frequency of the strip (22).

7. Microscope according to claim 1, wherein the magnetic-field source (18) is arranged to set up a magnetic field ({circle around (B)}) whose direction extends substantially transversely to the plane of the strip (22).

8. Microscope according to claim 1, wherein the magnetic-field source is arranged to set up a magnetic field whose direction extends substantially along the longitudinal mid-axis of the strip.

9. Microscope according to claim 1, wherein, in use, the means for vibrating the strip (22) create a mechanical interaction between the surface of the sample (E) and the tip (24) of the strip (22).

10. Microscope according to claim 1, wherein the radius of curvature of the tip (24) is about 30 nm at its extreme end.

11. Microscope according to claim 1, wherein, in use, the flow of an alternating electric current from the generator (34) through the loop (27) creates a variable magnetic moment ({circle around (M)}) which leads to align with the magnetic field ({circle around (B)}) set up by the magnetic field source (18) and which consequently deforms the strip (22) in a vibration.

12. Microscope according to claim 1, wherein the single turn of the loop (27) extends along two branches which are distinct at a part of the strip (22) linked to the body (20).

13. Microscope according to claim 1, wherein the single turn of the loop (27) extends over the length of the strip (22).

14. Microscope according to claim 1, wherein the electrical-conduction means (26A, 26B) forming the single turn of the loop (27) have a thickness between 5 nm and 500 nm.

15. Microscope according to claim 1, wherein said single turn of the loop (27) is disposed on at least one surface of the strip (22).