Scanning mechanism and scanning probe microscope

Patent metadata

Field	Value
Publication number	US-9625491-B2
Application number	US-201514614550-A
Country	US
Kind code	B2
Filing date	Feb 5, 2015
Priority date	Aug 8, 2012
Publication date	Apr 18, 2017
Grant date	Apr 18, 2017

Abstract

A scanning mechanism includes a movable portion to which a scanning target object is attached, and an X-Y actuator to scan the movable portion in an X direction and a Y direction perpendicular to the X direction. The X-Y actuator is symmetrical with respect to a straight line parallel to the Y direction and asymmetrical with respect to a straight line parallel to the X direction.

First claim

What is claimed is:

1. A scanning mechanism to scan a scanning target object at a first speed in an X direction and at a second speed in a Y direction perpendicular to the X direction, comprising:
a movable stage to which the scanning target object is attached; and
an X-Y actuator to scan the movable stage in the X direction at the first speed, the first speed being faster than the second speed, and in the Y direction at the second speed, the X-Y actuator being symmetrical with respect to a straight line parallel to the Y direction and asymmetrical with respect to a straight line parallel to the X direction, wherein the X-Y actuator comprises a first X actuator, a second X actuator and a single Y actuator, the first X actuator and the second X actuator configured to scan the movable stage in the X direction and the Y actuator configured to scan the movable stage in the Y direction.

2. The scanning mechanism according to claim 1 , further comprising a fixed frame surrounding the movable stage,
wherein the first and second X actuators are arranged on both sides of the movable stage along an X-axis between the fixed frame and the movable stage along the X-axis, and
the Y actuator is arranged between the fixed frame and the movable stage along a Y-axis perpendicular to the X-axis.

3. The scanning mechanism according to claim 2 , wherein the Y actuator is larger in displacement amount per unit driving signal than the first and second X actuators.

4. The scanning mechanism according to claim 3 , wherein the first X actuator comprises a first multilayer piezoelectric element, the second X actuator comprises a second multilayer piezoelectric element, and the Y actuator comprises a third multilayer piezoelectric element,
the first multilayer piezoelectric element and the second multilayer piezoelectric element are substantially identical, and
a length of the third multilayer piezoelectric element in a displacement direction is larger than a length of each of the first and the second multilayer piezoelectric element in the displacement direction.

5. The scanning mechanism according to claim 3 , wherein the first X actuator and the second X actuator comprise a first multilayer piezoelectric element and a second multilayer piezoelectric element, respectively,
the first multilayer piezoelectric element and the second multilayer piezoelectric element are substantially identical,
the third multilayer piezoelectric element comprises two piezoelectric elements, an A piezoelectric element and a B piezoelectric element,
the A piezoelectric element and the B piezoelectric element being connected in series in a displacement direction through an elastic member held by the fixed frame, and
a sum of a length of the A piezoelectric element and a length of the B piezoelectric element in a displacement direction is larger than a length of each of the first multilayer piezoelectric element and the second multilayer piezoelectric element in the displacement direction.

6. The scanning mechanism according to claim 5 , wherein both the A piezoelectric element and the B piezoelectric element are substantially identical to both the first multilayer piezoelectric element and the second multilayer piezoelectric element.

7. The scanning mechanism according to claim 2 , further comprising:
first and second elastic portions provided on both sides of the movable stage along the X-axis; and
third and fourth elastic portions provided on both sides of the movable stage along the Y-axis, the first to fourth elastic portions being formed integrally with the movable stage, the first elastic portion being arranged between the movable stage and the first X actuator, the second elastic portion being arranged between the movable stage and the second X actuator, the third elastic portion being arranged between the movable stage and the Y actuator, and the fourth elastic portion being arranged between the movable stage and the fixed frame.

8. The scanning mechanism according to claim 7 , further comprising support portions supporting the first to fourth elastic portions, the support portions being formed integrally with the first to fourth elastic portions and fixed to the fixed frame.

9. The scanning mechanism according to claim 2 , wherein the movable stage holds the scanning target object so that the scanning target object is symmetrical with respect to a straight line parallel to the Y-axis.

10. The scanning mechanism according to claim 9 , further comprising a Z actuator held by the movable stage, the Z actuator holding a cantilever with its longitudinal direction being along the Y-axis, and scanning the cantilever in a Z direction perpendicular to an X-Y plane.

11. The scanning mechanism according to claim 10 , further comprising a light converging portion to converge, to the cantilever, light for detecting a displacement of the cantilever, the light converging portion being held by the movable stage, the Z actuator and the light converging portion being arranged side by side along the Y-axis in projection to the X-Y plane.

12. The scanning mechanism according to claim 10 , wherein the Z actuator includes two, substantially identical fourth multilayer piezoelectric elements capable of expanding and contracting along a Z-axis, and the two fourth multilayer piezoelectric elements extend from the movable stage to opposite sides along the Z-axis, respectively.

13. The scanning mechanism according to claim 11 , wherein the light converging portion comprises a single lens.

14. The scanning mechanism according to claim 13 , wherein the single lens has a diameter equal to or smaller than 10 mm.

15. The scanning mechanism according to claim 13 , wherein the single lens has an NA (Numerical Aperture) equal to or larger than 0.4.

16. The scanning mechanism according to claim 13 , wherein the Z actuator holds the cantilever at an angle of 5 degrees to 20 degrees with respect to the X-Y plane, and
the single lens is held by the movable stage to form an angle of 5 degrees to 20 degrees by an optical axis of the single lens with respect to the Z-axis.

17. A scanning probe microscope comprising a scanning mechanism according to claim 1 .

18. The scanning mechanism according to claim 1 , wherein X-Y actuator comprises less actuators in the Y direction than in the X direction.

19. The scanning mechanism according to claim 1 , wherein the X-Y actuator consists of one Y-actuator.

20. The scanning mechanism according to claim 1 , wherein the Y actuator comprises at least one piezoelectric element, wherein the at least one piezoelectric element is positioned such that a straight line passing through the center of the piezoelectric element passes through the center of gravity of the movable stage.

21. The scanning mechanism according to claim 1 , wherein the first X actuator is operably connected to a first side of the movable stage, the second X actuator is operably connected to a second side of the movable stage and the single Y actuator is operably connected to a third side of the movable stage.

22. A scanning mechanism to scan a scanning target object at a first speed in an X direction and at a second speed in a Y direction perpendicular to the X direction, comprising:
a movable stage to which the scanning target object is attached; and
a first X actuator operably connected to a first side of the movable stage, a second X actuator operably connected to a second side of the movable stage and a Y actuator consisting of a single Y actu

Assignees

• Olympus Corp

Inventors

• Sakai Nobuaki
• Uekusa Yoshitsugu

Classifications

• G01Q10/04 Primary

  Fine scanning or positioning · CPC title

• G01Q10/00 Primary

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

• G01Q20/02

  by optical means · CPC title