JP2012185066A - Scanning mechanism and scanning type probe microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detected light follow-up type scanning mechanism with reduced vibration noise due to inertial force generated when performing XY scanning.SOLUTION: A scanning mechanism 10 comprises: a fixing frame 11; an XY stage 13 with an XY movable section 14 capable of moving in XY directions; and piezo-electric elements 12A and 12B constituting an XY actuator to scan the XY movable section 14 in the XY directions. The scanning mechanism 10 also comprises: a piezo-electric element 21 held by the XY movable section 14; a holder 22 held by the piezo-electric element 21; and a cantilever 23 held by the holder 22. The piezo-electric element 21 configures a Z actuator which scans the cantilever 23 in a Z direction. The scanning mechanism 10 additionally has a light collecting section 25 held by the XY movable section 14. The light collection section 25 allows light for detecting a displacement of the cantilever 23 to enter the cantilever 23. The piezo-electric element 21 and the light collecting section 25 are arranged so as to be aligned when projected on an X-Y plane.

Description

  The present invention relates to a scanning probe microscope.

  A scanning probe microscope (SPM) is a scanning microscope that obtains information on the surface of a sample by mechanically scanning a mechanical probe with a scanning mechanism, and includes a scanning tunneling microscope (STM), an atomic force microscope (AFM). ), A scanning magnetic force microscope (MFM), a scanning near-field light microscope (SNOM), and the like. The scanning probe microscope raster-scans the mechanical probe and the sample relatively in the X and Y directions, obtains surface information of a desired sample region via the mechanical probe, and displays the mapping on the monitor TV.

  Among them, the AFM is the most widely used device, which has a cantilever having a mechanical probe at its free end, an optical displacement sensor for detecting the displacement of the cantilever, and a mechanical probe and a sample relatively. A scanning mechanism for scanning is provided as a main mechanical mechanism. As the optical displacement sensor, an optical lever type optical displacement sensor is most widely used because of its simple structure and high displacement detection sensitivity. The cantilever is irradiated with a light beam with a diameter of several μm to several tens of μm, and the reflection direction of the reflected light changes according to the warp of the lever using a two-part optical detector, etc. The probe operation is captured and output as an electrical signal. While controlling the scanning mechanism in the Z direction so that this output is constant, the scanning mechanism is similarly scanned in the XY direction, thereby mapping and displaying the uneven state of the sample surface on the computer monitor.

  In such an AFM, when observing a biological sample in a liquid, it is generally observed in combination with an inverted optical microscope. This is because the inverted optical microscope observation is effective not only for obtaining knowledge of the sample but also for positioning the cantilever at a specific part of the sample. In such an AFM, a lever scanning type scanning mechanism that scans the cantilever in XYZ is often used so as to be compatible with various biological samples and sample substrates.

  On the other hand, in the sample scan type biological AFM that scans the sample in XYZ, there are problems that simultaneous observation with an inverted optical microscope is not possible and there are many restrictions on the sample and the sample substrate. It is attracting attention as it can observe the movement of When observing the movement of a biological sample, what is required of the AFM is the observation speed. In this application, the goal is to obtain a screen within 1 second, preferably within 0.1 seconds. When attempting to increase the speed of such AFM, the electric circuit around the AFM device has reached a level that is possible even with devices currently on the market, and the problem lies in the mechanical mechanism. In particular, a scanning mechanism having a high scanning speed, a soft cantilever having a high resonance frequency, and an optical lever type optical displacement sensor capable of detecting the displacement of the cantilever are exemplified.

  For example, when an image of 100 pixels in the X direction and 100 pixels in the Y direction is captured in 0.1 seconds, the scanning frequency required for the scanning mechanism is 1 kHz, the scanning frequency in the Y direction is 10 Hz, and the scanning frequency in the Z direction is 100 kHz. Reach above.

  A high-frequency cantilever suitable for observing a biological sample is required to have a spring constant of 1 N / m or less and a resonance frequency of 300 kHz or more. The size of such a cantilever is as extremely small as about one-tenth that of a commercially available cantilever. For example, a cantilever made of silicon nitride has a length of 10 μm, a width of 2 μm, and a thickness of 0.1 μm. The spring constant is 0.1 N / m, the resonance frequency in the atmosphere is 1.2 MHz, and the resonance frequency in the liquid is about 400 kHz.

  Further, as an optical displacement sensor, a condensing optical system is required in which the spot diameter of convergent light is several μm or less in order to detect a very small cantilever displacement.

  As explained above, it is desirable that high-speed observation of a biological sample by AFM is possible in combination with observation with an inverted optical microscope, that is, a lever scan type AFM, and it is soft and has a resonance frequency. It is necessary to be able to use a high and small cantilever and to have a scanning mechanism that performs high-speed scanning.

Special table 2010-521893

  The disadvantage of the lever scan type AFM is that not only the cantilever but also the optical lever type optical displacement sensor must be scanned together. This is because the optical lever type optical displacement sensor is equipped with a light source, a detector, and a condensing optical system, so that it is difficult to reduce the size and weight, which hinders high-speed scanning. In order to overcome this drawback, there has been proposed a detection light tracking type scanning mechanism that performs XY scanning of only a condensing optical system together with a cantilever, as shown in JP-T-2010-521893. However, this scanning mechanism has the following problems.

  When a scanning object (hereinafter referred to as an XY movable part) is XY scanned, an inertial force is applied to the XY movable part in a direction opposite to the scanning direction. This increases as the scanning speed increases. Also, the heavier the XY movable part becomes, the larger it becomes. When the scanning frequency exceeds 1 kHz, the inertial force deforms the XY movable part, and this causes a shaking vibration in the XY movable part. The longer the dimension along the Z axis of the XY movable part, the greater the influence.

  The above-described conventional scanning mechanism is a detection light tracking type scanning mechanism in which the XY movable portion holds the Z actuator and the objective system, and simultaneously performs XY scanning thereof. In this scanning mechanism, for example, when the XY movable portion is scanned in a certain direction parallel to the XY plane, an inertial force acts on the XY movable portion in the opposite direction. However, in this scanning mechanism, since the Z actuator and the objective system are arranged in series in the Z direction, the XY movable portion has a long structure along the Z axis. As a result, the XY movable part is likely to generate a shaking vibration having an axis parallel to the XY plane as a rotation center. Further, since the cantilever held by the Z actuator is disposed at the end of the XY movable part, the vibration of the XY movable part is amplified, and there is a problem that the amount of vibration at the cantilever position becomes larger. That is, it can be said that such a scanning mechanism is easily affected by the inertial force generated during scanning and is likely to generate vibration noise. Such a scanning mechanism is undesirable for high-speed scanning of a scanning probe microscope that requires sub-nanometer order accuracy.

  The present invention has been made in consideration of such a situation, and an object of the present invention is to provide a detection light tracking type scanning mechanism in which vibration noise caused by inertia force generated during XY scanning is reduced. is there.

  The scanning mechanism of the present invention is held by the cantilever, an XY movable portion that can move in the XY direction parallel to the XY plane, an XY actuator that scans the XY movable portion in the XY direction, and the XY movable portion. A Z actuator that scans the cantilever in a Z direction perpendicular to the XY plane, and a light collecting unit that is held by the XY movable unit and that makes the light for detecting displacement of the cantilever incident on the cantilever. I have. The Z actuator and the light condensing unit are arranged so as to be aligned in the projection onto the XY plane.

  According to the present invention, there is provided a detection light tracking type scanning mechanism in which vibration noise caused by inertia force generated during XY scanning is reduced.

It is a top view of the scanning mechanism of a first embodiment. It is sectional drawing of the scanning mechanism in alignment with the AA in FIG. It is a top view of the scanning mechanism of 2nd embodiment. It is sectional drawing of the scanning mechanism along the BB line in FIG. It is a top view of the scanning mechanism which is a modification of 2nd embodiment. It is sectional drawing of the scanning mechanism along CC line in FIG. It is a top view of the scanning mechanism which is a modification of 2nd embodiment. FIG. 8 is a cross-sectional view of the scanning mechanism along the line DD in FIG. 7. It is a top view of the scanning mechanism which is a modification of 2nd embodiment. It is sectional drawing of the scanning mechanism along the EE line in FIG. A state in which the base part of the XY movable part is deformed by the impact of scanning is shown. It is a top view of the scanning mechanism of 3rd embodiment. It is sectional drawing of the scanning mechanism in alignment with the FF line | wire in FIG. It is a top view of the scanning mechanism which is a modification of 3rd embodiment. It is sectional drawing of the scanning mechanism along the GG line in FIG. It is sectional drawing of the scanning mechanism which is a modification of the modification of 3rd embodiment. 10 shows a scanning probe microscope according to a fourth embodiment. The scanning probe microscope which is a modification of 4th embodiment is shown. 10 shows a scanning probe microscope according to a fifth embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>
This embodiment is directed to a scanning mechanism. Hereinafter, the present embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a top view of the scanning mechanism of the present embodiment, and FIG. 2 is a cross-sectional view of the scanning mechanism along the line AA in FIG.

  As shown in FIGS. 1 and 2, the scanning mechanism 10 of this embodiment is disposed between a fixed frame 11, an XY stage 13 disposed in the fixed frame 11, and the XY stage 13 and the fixed frame 11. The piezoelectric element 12A extends along the X axis, and the piezoelectric element 12B extends along the Y axis disposed between the XY stage 13 and the fixed frame 11.

  The XY stage 13 includes an XY movable unit 14 that is movable along an X axis and a Y axis orthogonal to each other (that is, in an XY direction parallel to an XY plane including the X axis and the Y axis), and an XY movable unit 14 Support for supporting the elastic portions 16A and 16C provided on both sides along the X axis, the elastic portions 16B and 16D provided on both sides along the Y axis of the XY movable portion 14, and the elastic portions 16A to 16D Part 15.

  The support portions 15 of the XY stage 13 are located on both sides of the piezoelectric element 12A and the elastic portions 16A and 16C along the Y axis. In other words, the piezoelectric element 12B and the elastic portions 16B and 16D are located on both sides along the X axis. The support portion 15 is fixed to the fixed frame 11. The fixing of the support portion 15 is not limited to this, but is performed by, for example, screw fastening or adhesion.

  The elastic portions 16A and 16B have exactly the same shape except that their directions are different. Both of these have a cross shape. The elastic portions 16C and 16D have exactly the same shape except that their directions are different. Both of these have a T-shape. The elastic portion 16A located on the piezoelectric element 12A side has a pressing portion 17A that is pressed by the piezoelectric element 12A. The elastic portion 16B located on the piezoelectric element 12B side has a pressing portion 17B that is pressed by the piezoelectric element 12B.

  The elastic portions 16A and 16C have a rectangular plate-like portion that extends in the ZX plane and extends along the X axis, and a rectangular plate-like portion that extends in the YZ plane and extends along the Y axis. The rectangular plate-like portion that is elongated along the X axis is connected to the XY movable portion 14 at one end along the X axis, and the rectangular plate that is elongated at one end along the X axis along the Y axis. Connected to the central part of the shaped part. The rectangular plate-like portion that is elongated along the Y axis is connected to the support portion 15 at both ends along the Y axis.

  The elastic portions 16B and 16D have a rectangular plate-like portion that extends in the YZ plane and extends along the Y-axis, and a rectangular plate-like portion that extends in the ZX plane and extends in the X-axis. The rectangular plate-like portion elongated along the Y axis is connected to the XY movable portion 14 at one end along the Y axis, and the rectangular plate elongated at one end along the Y axis along the X axis. Connected to the central part of the shaped part. The rectangular plate-like portion that is elongated along the X axis has both end portions along the X axis connected to the support portion 15. The thickness of these plate-like portions, that is, the dimension along the Z-axis is not limited to this, but is the same as the thickness of the XY movable portion 14, for example.

  By having such a shape, the elastic portions 16A and 16C are easily elastically deformed along the Y axis, but are not easily deformed along the X axis. The elastic portions 16B and 16D are easily deformed elastically along the X axis, but are not easily deformed along the Y axis. Therefore, the XY movable part 14 is supported with high rigidity in the direction along the X axis by the elastic parts 16A and 16C, and is supported with high rigidity in the direction along the Y axis by the elastic parts 16B and 16D.

  The XY stage 13 is integrally formed. That is, the XY movable part 14, the support part 15, the elastic parts 16A to 16D, and the pressing parts 17A and 17B are integrally formed. The XY stage 13 is produced by selectively notching a metal block made of, for example, aluminum.

  The material of the fixed frame 11 preferably has a higher elastic modulus than the material of the XY stage 13. For example, the fixed frame 11 is made of stainless steel, and the XY stage 13 is made of aluminum.

  The piezoelectric element 12A is arranged so that a predetermined preload is applied between the pressing portion 17A of the elastic portion 16A and the fixed frame 11. The piezoelectric element 12B is arranged so that a predetermined preload is applied between the pressing portion 17B of the elastic portion 16B and the fixed frame 11.

  The piezoelectric element 12A is disposed so that a straight line passing through the center of gravity of the XY movable portion 14 and parallel to the X axis passes through the center of the piezoelectric element 12A. The piezoelectric element 12B is arranged so that a straight line passing through the center of gravity of the XY movable portion 14 and parallel to the Y axis passes through the center of the piezoelectric element 12B.

  The piezoelectric element 12A is an X actuator for moving the XY movable part 14 along the X axis via the elastic part 16A, and can expand and contract along the X axis according to voltage application. The piezoelectric element 12B is a Y actuator for moving the XY movable portion 14 along the Y axis via the elastic portion 16B, and can expand and contract along the Y axis in response to voltage application.

  The piezoelectric element 12A and the piezoelectric element 12B are composed of, for example, two substantially identical stacked piezoelectric elements. The piezoelectric element 12A and the piezoelectric element 12B constitute an XY actuator that scans the XY movable unit 14 in a direction parallel to the XY plane.

  The scanning mechanism 10 also includes a piezoelectric element 21 held by the XY movable unit 14, a holder 22 held by the piezoelectric element 21, and a cantilever 23 held by the holder 22. One end of the piezoelectric element 21 is fixed to the XY movable portion 14 and extends in the −Z direction. A holder 22 that holds the cantilever 23 is held at the free end of the piezoelectric element 21. The piezoelectric element 21 is composed of, for example, a laminated piezoelectric element. The piezoelectric element 21 can expand and contract along the Z axis in response to voltage application. The piezoelectric element 21 constitutes a Z actuator that scans the cantilever 23 in the Z-axis direction perpendicular to the XY plane. The cantilever 23 has a mechanical probe 24 at its free end. The cantilever 23 extends, for example, along the X axis. The cantilever 23 may be attached to the holder 22 in a replaceable manner.

  The scanning mechanism 10 further includes a light collecting unit 25 held by the XY movable unit 14. The condensing unit 25 functions to make the cantilever 23 enter light for detecting the displacement of the cantilever 23, which is emitted from an optical displacement sensor (not shown), for example, an optical lever sensor. The condensing part 25 is not limited to this, For example, it has the two condensing lenses 26A and 26B. The condenser lenses 26 </ b> A and 26 </ b> B are held by a cylindrical body 27 that is fixed to the XY movable portion 14 and extends through the XY movable portion 14.

  The piezoelectric element 21 and the light collecting unit 25 are arranged so as to be aligned in the projection onto the XY plane. In other words, one of the piezoelectric element 21 and the light converging unit 25 is located outside the other without overlapping each other on the projected XY plane. The piezoelectric element 21 and the light collecting unit 25 are not limited to this, but are arranged along the direction in which the cantilever 23 extends, that is, along the X axis, for example.

  In the scanning mechanism 10 configured as described above, the piezoelectric element 12A expands and contracts along the X axis during X scanning. When the piezoelectric element 12A extends, the piezoelectric element 12A pushes the XY movable part 14 while elastically deforming the elastic part 16A. Accordingly, the XY movable unit 14 is moved in one direction along the X axis. Accordingly, the elastic portion 16C is elastically deformed by being pushed by the XY movable portion 14. Further, the elastic portions 16B and 16D are also elastically deformed because they are pulled in the moving direction of the XY movable portion 14. When the piezoelectric element 12A contracts, the XY movable portion 14 is moved in the reverse direction along the X axis according to all the restoring forces of the elastic portions 16A to 16D that are elastically deformed. In this way, the XY movable unit 14 is scanned with high straightness in the X direction.

  Similarly, during Y scanning, the piezoelectric element 12B expands and contracts along the Y axis. When the piezoelectric element 12B extends, the piezoelectric element 12B pushes the XY movable part 14 while elastically deforming the elastic part 16B. As a result, the XY movable unit 14 is moved in one direction along the Y axis. Accordingly, the elastic portion 16D is elastically deformed by being pushed by the XY movable portion 14. Furthermore, the elastic portions 16A and 16C are also elastically deformed because they are pulled in the moving direction of the XY movable portion 14. When the piezoelectric element 12B contracts, the XY movable portion 14 is moved in the reverse direction along the Y axis in accordance with all the restoring forces of the elastic portions 16A to 16D that are elastically deformed. In this way, the XY movable unit 14 is scanned with high straightness in the Y direction.

  Since the respective central axes of the piezoelectric element 12A and the piezoelectric element 12B pass through the center of gravity of the XY movable part 14, even when the XY movable part 14 is moved at high speed, it is difficult for rotational movement due to inertial force to occur. For this reason, the XY movable part 14 can be scanned in the XY directions with high speed and high straightness.

  When the XY movable unit 14 is scanned in the XY direction, the cantilever 23 is also scanned in the XY direction together with the piezoelectric element 21. Therefore, the cantilever 23 is also scanned with high speed and high straightness.

  When the XY movable unit 14 is scanned in the XY direction, the light collecting unit 25 is also scanned in the XY direction. Accordingly, the light collecting unit 25 is also scanned in the XY directions with high speed and high straightness.

  A collimated laser beam 29 emitted from an optical lever sensor (not shown) is incident on the condensing unit 25 in parallel to the optical axis 28 of the condensing unit 25. The condensing unit 25 condenses and irradiates the incident laser beam 29 on the free end of the cantilever 23. The laser beam 29 reflected by the free end of the cantilever 23 is incident on an optical detector (not shown) through the condenser 25.

  When the XY movable unit 14 is scanned in the XY direction, the focal position of the condensing unit 25 is also scanned in the XY direction together with the condensing unit 25, so that the laser beam 29 condensed by the condensing unit 25 The condensing spot is also scanned in the XY directions by the same distance as the condensing unit 25. Therefore, the condensing spot of the laser beam 29 created by the condensing unit 25 is scanned in the XY directions at high speed and with high straightness.

  As described above, in the scanning mechanism 10, the condensing spot of the laser beam 29 formed by the cantilever 23 and the condensing unit 25 is scanned at the same distance in the XY direction with high speed and high straightness.

  Further, in the scanning mechanism 10, the light collecting unit 25 and the piezoelectric element 21 are arranged so as to be aligned along the X axis in the projection onto the XY plane. For this reason, the length along the Z-axis of the XY movable part 14 including the light collecting part 25 and the piezoelectric element 21 is suppressed to be short. As a result, “swing vibration of the XY movable unit 14 due to inertial force” generated when the XY movable unit 14 is scanned in the XY direction at high speed is reduced. Further, since the cantilever 23 approaches the XY plane passing through the center of gravity of the XY movable portion 14, an increase in the shaking vibration of the cantilever 23 is also avoided.

  Accordingly, in the scanning mechanism 10, the condensing spot of the laser light 29 formed by the cantilever 23 and the condensing unit 25 is scanned at the same distance in the XY direction at high speed and with high linearity, and thus is caused by the inertia force generated during XY scanning. A scanning mechanism for detecting and following the detected light with reduced vibration noise is provided. As a result, a highly accurate detection light tracking type scanning mechanism having high speed and high straightness is provided.

<Second embodiment>
This embodiment is directed to a scanning mechanism. Hereinafter, the present embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a top view of the scanning mechanism 30 of the present embodiment, and FIG. 4 is a cross-sectional view of the scanning mechanism 30 along the line BB in FIG. 3 and 4, members having the same reference numerals as those shown in FIGS. 1 and 2 are similar members, and detailed description thereof is omitted.

  As shown in FIGS. 3 and 4, the XY stage 33 has an XY movable portion 34, and the XY movable portion 34 has a square hole 35 extending along the Z axis on the lower surface thereof. The square hole 35 is fixed with a piezoelectric element 21 that expands and contracts along the Z-axis in response to voltage application. As a result, the center of gravity of the piezoelectric element 21 is within the thickness (the dimension along the Z axis) of the XY movable portion 34. That is, the center of gravity of the piezoelectric element 21 is brought close to the XY plane passing through the center of gravity of the XY movable part 34. This also brings the position of the cantilever 23 closer to the XY plane passing through the center of gravity of the XY movable portion 34. A holder 22 for holding the cantilever 23 is attached to the free end of the piezoelectric element 21.

  The light collecting unit 25 penetrates the XY movable unit 34 and is held by the XY movable unit 34. The condensing unit 25 is desirably held so as to substantially coincide with the XY plane passing through the center of gravity of the XY movable unit 34 so that the center of gravity thereof is within the thickness of the XY movable unit 34 in the Z direction.

  In the scanning mechanism 30 configured as described above, the piezoelectric element 21 and the light collecting unit 25 are arranged so as to be aligned along the X axis in the projection onto the XY plane. Further, the centroids of the piezoelectric element 21 and the light converging part 25 are both within the thickness of the XY movable part 34 in the Z direction. As a result, “swing vibration of the XY movable part 34 due to inertial force” that occurs when the XY movable part 34 is scanned in the XY direction at high speed is reduced. Further, since the cantilever 23 approaches the XY plane passing through the center of gravity of the XY movable portion 34, an increase in the shaking vibration of the cantilever 23 is also avoided.

[Modification 1]
Further, this scanning mechanism can be modified as follows. A scanning mechanism 40, which is a modification of the second embodiment, is shown in FIGS. FIG. 5 is a top view of a scanning mechanism 40 which is a modification of the present embodiment, and FIG. 6 is a cross-sectional view of the scanning mechanism 40 along the line CC in FIG. 5 and 6, members having the same reference numerals as those shown in FIGS. 1 and 2 are similar members, and detailed description thereof is omitted.

  As shown in FIGS. 5 and 6, the scanning mechanism 40 has an XY stage 43, and the XY stage 43 has an XY movable unit 44. The scanning mechanism 40 also includes the piezoelectric element 21 held by the XY movable portion 44, the holder 22 held by the piezoelectric element 21, the cantilever 23 held by the holder 22, and the piezoelectric element held by the XY movable portion 44. 41 and a pseudo holder 42 held by the piezoelectric element 41.

  One end of the piezoelectric element 21 is fixed to the XY movable portion 44 and extends in the −Z direction. Further, one end of the piezoelectric element 41 is fixed to the XY movable portion 44 and extends in the + Z direction. That is, each of the piezoelectric element 21 and the piezoelectric element 41 extends from the XY movable portion 44 to the opposite side along the Z axis.

  The piezoelectric element 21 and the piezoelectric element 41 are composed of, for example, substantially the same stacked piezoelectric element, and can expand and contract along the Z-axis in response to voltage application. The piezoelectric element 21 and the piezoelectric element 41 constitute a Z actuator that scans the cantilever 23 in the Z-axis direction perpendicular to the XY plane.

  A holder 22 for holding the cantilever 23 is attached to the free end of the piezoelectric element 21 provided on the lower surface of the XY movable portion 44. That is, the cantilever 23 is held at the free end of the piezoelectric element 21. A pseudo holder 42, which is the same member as the holder 22, is attached to the free end of the piezoelectric element 41 provided on the upper surface of the XY movable portion 44. The pseudo holder 42 can be replaced if it is a member having the same mass as the holder 22.

  When scanning the cantilever 23 in the Z direction, a Z drive signal is supplied to the two piezoelectric elements 21 and 41 by a Z piezoelectric drive unit (not shown), and the two piezoelectric elements 21 and 41 are expanded and contracted in the opposite direction by the same amount. Thereby, the force along the Z axis that the expansion and contraction of the piezoelectric element 21 gives to the XY movable portion 44 is canceled by the expansion and contraction of the piezoelectric element 41. Thereby, the vibration in the Z direction of the XY movable part 44 caused by the expansion and contraction of the piezoelectric element 21 is suppressed to substantially zero.

  In the scanning mechanism 40 configured as described above, the two piezoelectric elements 21 and 41 and the light converging unit 25 are arranged so as to be aligned along the X axis in the projection onto the XY plane. The condensing unit 25 is desirably held so as to substantially coincide with an XY plane passing through the center of gravity of the XY movable unit 44 so that the center of gravity thereof falls within the thickness of the XY movable unit 44 in the Z direction. Since the two piezoelectric elements 21 and 41 have substantially the same shape and the same mass, the Z actuator constituted by the two piezoelectric elements 21 and 41 has a center of gravity within the thickness of the XY movable portion 44 in the Z direction. Desirably, the XY movable portion 44 is held so as to substantially coincide with the XY plane passing through the center of gravity. As a result, “swing vibration of the XY movable part 44 due to inertial force” that occurs when the XY movable part 44 is scanned in the XY direction at high speed is reduced. Further, the Z actuator composed of the two piezoelectric elements 21 and 41 is substantially symmetrical with respect to the XY plane passing through the center of gravity of the XY movable portion 44. This serves as a counterbalance that cancels out “swaying vibration of the XY movable portion 44 caused by inertial force”. As a result, “swaying vibration of the XY movable portion 44 caused by inertial force” is further reduced. In addition, the vibration noise generated when the cantilever 23 is scanned in the Z direction can be suppressed to almost zero by the Z actuator composed of the two piezoelectric elements 21 and 41.

[Modification 2]
Further, this scanning mechanism can be modified as follows. A scanning mechanism 50, which is a modification of the second embodiment, is shown in FIGS. FIG. 7 is a top view of a scanning mechanism 50 which is a modification of the present embodiment, and FIG. 8 is a cross-sectional view of the scanning mechanism 50 along the line DD in FIG. 7 and 8, members denoted by the same reference numerals as those shown in FIGS. 5 and 6 are similar members, and detailed description thereof is omitted.

  As shown in FIGS. 7 and 8, the scanning mechanism 50 has an XY stage 53, and the XY stage 53 has an XY movable portion 54. The scanning mechanism 50 also includes the piezoelectric element 21 held by the XY movable portion 54, the holder 22 held by the piezoelectric element 21, the cantilever 23 held by the holder 22, and the piezoelectric element held by the XY movable portion 54. 41 and a pseudo holder 42 held by the piezoelectric element 41.

  The scanning mechanism 50 further has a single lens 56 held by the XY movable portion 54. The single lens 56 is disposed in a through hole 55 formed in the XY movable portion 54 and is within the thickness of the XY movable portion 54. The single lens 56 is desirably held so that the center of gravity thereof substantially coincides with the XY plane passing through the center of gravity of the XY movable unit 54. The single lens 56 has the same light collecting performance as the light collecting unit 25 shown in FIG. That is, the single lens 56 constitutes a condensing unit that makes light for detecting the displacement of the cantilever 23 incident on the cantilever 23. For example, the single lens 56 has an optical characteristic such that its NA is 0.4 or more so that light can be condensed even on a small cantilever having a length of 10 μm and a width of 2 μm. Since the focal spot diameter is obtained by 1.22 × wavelength / NA, for example, when a red laser with a wavelength of 650 nm is used as the detection light of the optical lever sensor, the focal spot diameter becomes about 2 μm when the NA is 0.4. Because. The single lens 56 preferably has a diameter of 10 mm or less. This is because it is important to make the XY movable portion 54 small and light in order to increase the speed of the XY scanning.

  In the scanning mechanism 50 configured as described above, the two piezoelectric elements 21 and 41 and the single lens 56 are arranged so as to be aligned along the X axis in the projection onto the XY plane. The single lens 56 is desirably held so that its center of gravity is substantially coincident with an XY plane passing through the center of gravity of the XY movable unit 54 so that the single lens 56 itself can be accommodated in the XY movable unit 54. In addition, since the two piezoelectric elements 21 and 41 have substantially the same shape and mass, the Z actuator constituted by the two piezoelectric elements 21 and 41 has an XY plane whose center of gravity passes through the center of gravity of the XY movable portion 54. Is held to almost match. As a result, “swing vibration of the XY movable part 54 due to inertial force” generated when the XY movable part 54 is scanned in the XY direction at high speed is reduced. Further, the Z actuator composed of the two piezoelectric elements 21 and 41 is substantially symmetrical with respect to the XY plane passing through the center of gravity of the XY movable portion 54. This acts as a counterbalance that cancels out “swaying vibration of the XY movable portion 54 caused by inertial force”. As a result, “swing vibration of the XY movable portion 54 caused by inertial force” is further reduced. In addition, the vibration noise generated when the cantilever 23 is scanned in the Z direction can be suppressed to almost zero by the Z actuator composed of the two piezoelectric elements 21 and 41.

  Furthermore, since the condensing part is a small and light single lens, the inertial force applied to the condensing part is reduced. As a result, “swing vibration of the XY movable portion 54 caused by inertial force” is further reduced. In addition, the XY movable unit 54 itself can be reduced in size and weight, and as a result, the resonance frequency of the scanning mechanism can be increased. This is effective for high-speed scanning.

[Modification 3]
Further, this scanning mechanism can be modified as follows. A scanning mechanism 60, which is a modification of the second embodiment, is shown in FIGS. FIG. 9 is a top view of a scanning mechanism 60 that is a modification of the present embodiment, and FIG. 10 is a cross-sectional view of the scanning mechanism 60 taken along line EE in FIG. 9 and 10, members denoted by the same reference numerals as those illustrated in FIGS. 7 and 8 are similar members, and detailed description thereof is omitted.

  As shown in FIGS. 9 and 10, the scanning mechanism 60 has an XY stage 63, and the XY stage 63 has an XY movable portion 64. The scanning mechanism 60 also includes the piezoelectric element 21 held by the XY movable part 64, the holder 22 held by the piezoelectric element 21, the cantilever 23 held by the holder 22, and the piezoelectric element held by the XY movable part 64. 41 and a pseudo holder 42 held by the piezoelectric element 41.

  A holder 22 for holding the cantilever 23 is attached to the free end of the piezoelectric element 21 provided on the lower surface of the XY movable portion 64. The holder 22 holds the cantilever 23 with an inclination of 5 degrees to 20 degrees with respect to the XY plane. This is to avoid interference between the lever surface of the cantilever 23 and a sample arranged in parallel to an XY plane (not shown), and is implemented in almost all AFMs. A pseudo holder 42, which is the same member as the holder 22, is attached to the free end of the piezoelectric element 41 provided on the upper surface of the XY movable portion 64. The pseudo holder 42 can be replaced if it is a member having the same mass as the holder 22.

  The scanning mechanism 60 further has a single lens 66 held by the XY movable portion 64. The single lens 66 is tilted and held so that its optical axis 68 is 5 degrees to 20 degrees with respect to an axis perpendicular to the XY plane so that convergent light is incident perpendicularly to the lever surface of the cantilever 23. Has been. The single lens 66 is disposed in a through hole 65 formed in the XY movable portion 64 and is within the thickness of the XY movable portion 64. The single lens 66 is desirably held so that the center of gravity thereof substantially coincides with the XY plane passing through the center of gravity of the XY movable unit 64. Further, the single lens 66 has an optical characteristic that its NA is 0.4 or more so that light can be condensed even on a small cantilever having a length of 10 μm and a width of 2 μm.

  In the scanning mechanism 60 configured as described above, the two piezoelectric elements 21 and 41 and the single lens 66 are arranged so as to be aligned along the X axis in the projection onto the XY plane. The single lens 66 is held so that the center of gravity thereof substantially coincides with the XY plane passing through the center of gravity of the XY movable unit 64. Further, since the two piezoelectric elements 21 and 41 have substantially the same shape and mass, the Z actuator constituted by the two piezoelectric elements 21 and 41 has an XY plane whose center of gravity passes through the center of gravity of the XY movable unit 64. Is held to almost match. As a result, “swing vibration of the XY movable part 64 due to inertial force” that occurs when the XY movable part 64 is scanned in the XY direction at high speed is reduced. Further, the Z actuator composed of the two piezoelectric elements 21 and 41 is substantially symmetrical with respect to the XY plane passing through the center of gravity of the XY movable portion 64. This serves as a counter balance that cancels out “swaying vibration of the XY movable portion 64 caused by inertial force”. As a result, “swaying vibration of the XY movable part 64 due to inertial force” is further reduced. In addition, the vibration noise generated when the cantilever 23 is scanned in the Z direction can be suppressed to almost zero by the Z actuator composed of the two piezoelectric elements 21 and 41. Furthermore, since the optical axis 68 of the single lens 66 is held at an angle of 5 degrees to 20 degrees with respect to the axis perpendicular to the XY plane, the convergent light is incident on the cantilever 23 perpendicularly. Can do. The single lens 66 has an optical characteristic with an NA of 0.4 or more. As a result, the diameter of the focused spot formed on the cantilever 23 can be reduced to about 2 μm. This is effective in improving the accuracy of detecting the displacement of the cantilever 23.

<Third embodiment>
This embodiment is directed to a scanning mechanism. Hereinafter, the present embodiment will be described with reference to FIGS.

  The scanning mechanisms 40, 50, 60 shown in the second embodiment have two piezoelectric elements 21, 41 extending on the opposite side along the Z axis, and vibrations generated when the cantilever 23 is scanned in the Z direction. Noise is suppressed to almost zero. However, since scanning in the Z direction extends to a maximum of 100 kHz or more, there is a problem that the base portion of the XY movable portion provided with the two piezoelectric elements 21 and 41 is deformed by the impact of scanning. FIG. 11 shows a state in which the base portion of the XY movable portion 54 taking the scanning mechanism 50 as an example is deformed. This deformation is transmitted to the condensing part (single lens 56 in the scanning mechanism 50) as vibration noise of 100 kHz or more at the maximum. Since the light condensing part is held by the XY movable part only at its outer peripheral part, it cannot be said that the light condensing part is strong against vibration noise. This hinders high accuracy of AFM observation.

  FIG. 12 is a top view of the scanning mechanism 70 according to the present embodiment that solves the above problem, and FIG. 13 is a cross-sectional view of the scanning mechanism 70 taken along line FF in FIG. 12 and 13, members denoted by the same reference numerals as those shown in FIGS. 7 and 8 are similar members, and detailed description thereof is omitted.

  As shown in FIGS. 12 and 13, the scanning mechanism 70 has an XY stage 73, and the XY stage 73 has an XY movable portion 74. The scanning mechanism 70 also includes the piezoelectric element 21 held by the XY movable portion 74, the holder 22 held by the piezoelectric element 21, the cantilever 23 held by the holder 22, and the piezoelectric element held by the XY movable portion 74. 41, a pseudo holder 42 held by the piezoelectric element 41, and a single lens 76 held by the XY movable portion 74. The single lens 76 is disposed in a through hole 75 formed in the XY movable part 74 and is within the thickness of the XY movable part 74. Desirably, the single lens 76 is held so that the center of gravity thereof substantially coincides with the XY plane passing through the center of gravity of the XY movable unit 74.

  A Z actuator composed of a single lens 76 and two piezoelectric elements 21 and 41 provided in the XY movable portion 74 is arranged so as to be aligned along the X axis in the projection onto the XY plane. An opening 77 that penetrates the XY movable portion 74 is provided between the single lens 76 and the Z actuator composed of the two piezoelectric elements 21 and 41 so as to mechanically separate them.

  In the scanning mechanism 70 configured in this way, an opening 77 that mechanically separates the two piezoelectric elements 21 and 41 and the single lens 76 is provided, so that scanning in the Z direction is performed. The transmission of vibration noise generated at the time to the single lens 76 is reduced.

[Modification]
Further, this scanning mechanism can be modified as follows. A scanning mechanism 80, which is a modification of the third embodiment, is shown in FIGS. FIG. 14 is a top view of a scanning mechanism 80 which is a modification of the present embodiment, and FIG. 15 is a cross-sectional view of the scanning mechanism 80 taken along the line GG in FIG. 14 and 15, members denoted by the same reference numerals as those shown in FIGS. 12 and 13 are similar members, and detailed description thereof is omitted.

  As shown in FIGS. 14 and 15, the scanning mechanism 80 has an XY stage 83, and the XY stage 83 has an XY movable portion 84. The scanning mechanism 80 also includes the piezoelectric element 21 held by the XY movable portion 84, the holder 22 held by the piezoelectric element 21, the cantilever 23 held by the holder 22, and the piezoelectric element held by the XY movable portion 84. 41, the pseudo holder 42 held by the piezoelectric element 41, and the single lens 86 held by the XY movable portion 84.

  The single lens 86 is disposed in a through hole 85 formed in the XY movable portion 84. A through hole 85 provided in the XY movable portion 84 for holding the single lens 86 has an elliptical shape or an oval shape in which the outer shape (circle) of the single lens 86 is slightly widened. The hole 85 is held at a position away from the two piezoelectric elements 21 and 41. That is, a part of the outer peripheral portion of the single lens 86, for example, half to 3/4 is joined to the through hole 85, and the remaining outer peripheral portion is held so as not to contact the through hole 85. As a result, a gap, that is, an opening 87 is formed between the portion of the single lens 86 closest to the two piezoelectric elements 21 and 41 and the XY movable portion 84. The opening 87 mechanically separates the single lens 86 and the XY movable part 84. Further, the single lens 86 is accommodated within the thickness of the XY movable portion 84, and is desirably held so that its center of gravity substantially coincides with the XY plane passing through the center of gravity of the XY movable portion 84.

  In the scanning mechanism 80 configured as described above, an opening 87 is formed between the two piezoelectric elements 21 and 41 and the single lens 86 so as to mechanically separate them. Further, the single lens 86 is held at a position away from the two piezoelectric elements 21 and 41. For this reason, the single lens 86 is completely mechanically separated from the base portion of the XY movable portion 84 that holds the two piezoelectric elements 21 and 41. As a result, transmission of vibration noise generated during scanning in the Z direction to the single lens 86 is further reduced.

  Another modification of the third embodiment is shown in FIG. The scanning mechanism 90 shown in FIG. 16 is the same as the scanning mechanism 80 except for the arrangement of the single lens 96. The single lens 96 may be held tilted so that its optical axis 98 is 5 degrees to 20 degrees with respect to an axis perpendicular to the XY plane. Even in such a configuration, a similar effect can be obtained with respect to reduction of transmission of vibration noise to the single lens 96.

<Fourth embodiment>
The present embodiment is directed to a scanning probe microscope including the scanning mechanism of the second embodiment. Hereinafter, the present embodiment will be described with reference to FIG. FIG. 17 shows a scanning probe microscope 100 according to the present embodiment.

  As shown in FIG. 17, the scanning probe microscope 100 according to the present embodiment includes a scanning mechanism 50 that holds the cantilever 23, a host computer 101, a controller 102 that includes a Z control unit 103, a laser light source 111, and a split light source. A detector 112, a Z piezoelectric driver 106, and an XY piezoelectric driver 107 are provided. A sample 116 placed on the sample stage 117 is disposed at a position facing the cantilever 23.

  The scanning mechanism 50 is for scanning the cantilever 23 along the X axis, the Y axis, and the Z axis, and the detailed configuration thereof is as described in the second embodiment (FIGS. 7 and 8). The scanning mechanism 50 is held by a lens frame (not shown).

  The cantilever 23 is provided with a probe disposed opposite to the sample 116 at the free end of the flexible lever portion, and the cantilever 23 is displaced along the Z axis in accordance with the interaction with the sample 116.

  The laser light source 111 and the split detector 112 constitute an optical displacement sensor for optically detecting the displacement along the Z axis of the free end of the cantilever 23, and are held by a lens frame (not shown).

  The Z piezoelectric driver 106 is for driving the two piezoelectric elements 21 and 41 mounted on the scanning mechanism 50.

  The XY piezoelectric driver 107 is for driving the piezoelectric elements 12A and 12B mounted on the scanning mechanism 50.

  The controller 102 is for controlling the Z piezoelectric driver 106 and the XY piezoelectric driver 107.

  The host computer 101 constitutes a processing unit that acquires physical information of the sample 116 based on the displacement information of the cantilever 23 and the scanning information of the scanning mechanism 50.

  The scanning probe microscope of the present embodiment operates as follows.

  The optical displacement sensor composed of the laser light source 111 and the split detector 112 is an optical lever sensor often used in, for example, a scanning probe microscope. The collimated laser light 113 emitted from the laser light source 111 is provided in the scanning mechanism 50. A condensed spot having a diameter of about several μm is formed on the cantilever 23 through the single lens 56, and the reflected light is received by the split detector 112, so that the Z of the mechanical probe 24 at the free end of the cantilever 23 is received. Capture displacement. The split detector 112 outputs a displacement signal reflecting the Z displacement of the cantilever 23 to the controller 102.

  The controller 102 generates an XY scanning signal for raster scanning in the XY directions, and supplies the XY scanning signal to the XY piezoelectric driver 107 and the host computer 101. The controller 102 includes a Z control unit 103. The Z control unit 103 generates a Z scanning signal for controlling the Z piezoelectric driver 106 so that the displacement information of the cantilever 23 obtained by the divided detector 112 is kept constant. Then, the Z scanning signal is supplied to the Z piezoelectric driver 106 and the host computer 101.

  The Z piezoelectric driver 106 amplifies the Z scanning signal supplied from the controller 102 with a predetermined gain to generate a Z driving signal, and supplies the Z driving signal to the two piezoelectric elements 21 and 41 mounted on the scanning mechanism 50. To do.

  The XY piezoelectric driver 107 amplifies the XY scanning signal supplied from the controller 102 with a predetermined gain to generate an XY driving signal, and supplies the XY driving signal to the piezoelectric elements 12A and 12B mounted on the scanning mechanism 50. Specifically, the X drive signal generated by amplifying the X scan signal supplied from the controller 102 is supplied to the piezoelectric element 12A, and the Y drive signal generated by amplifying the Y scan signal supplied from the controller 102 is The piezoelectric element 12B is supplied.

  The host computer 101 constructs a three-dimensional image of the surface shape of the sample 116 based on the XY scanning signal and the Z scanning signal supplied from the controller 102, and displays this on the monitor.

  In the scanning probe microscope 100, the scanning mechanism 50 is used to perform high-speed scanning in the XY directions with high accuracy. Therefore, according to the scanning probe microscope 100, the observation resolution is improved and the observation time is shortened.

[Modification]
Further, the scanning probe microscope can be modified as follows. FIG. 18 shows a scanning probe microscope 120 that is a modification of the fourth embodiment. 18, members denoted by the same reference numerals as those shown in FIG. 17 are the same members, and detailed description thereof is omitted.

  The scanning probe microscope 120 shown in FIG. 18 has a configuration in which the scanning mechanism 50 shown in FIG. Furthermore, a laser light source 121, a beam splitter 122, a wave plate 123, and a split detector 124 are provided.

  The laser light source 121, the beam splitter 122, the wave plate 123, and the split detector 124 constitute an optical displacement sensor for optically detecting the displacement along the Z axis of the free end of the cantilever 23, and each is not shown. It is held in a mirror frame. The optical displacement sensor composed of these is, for example, an optical lever sensor often used in a scanning probe microscope. The collimated laser light 125 emitted from the laser light source 121 is scanned through the beam splitter 122 and the wave plate 123. A single lens 66 provided in the mechanism 60 is irradiated to form a focused spot having a diameter of about 2 μm on the cantilever 23. The reflected light passes through the wave plate 123, is deflected by the beam splitter 122, and enters the split detector 124. The split detector 124 outputs a displacement signal reflecting the Z displacement of the cantilever 23 to the controller 102.

  In the scanning probe microscope 120, by using the scanning mechanism 60, high-speed scanning in the XY directions is performed with high accuracy. Therefore, according to the scanning probe microscope 120, the observation resolution is improved and the observation time is shortened. Further, according to the scanning probe microscope 120, the diameter of the focused spot irradiated onto the cantilever by the scanning mechanism 60 can be reduced to about 2 μm in diameter. This is effective in improving the accuracy of detecting the displacement of the cantilever 23. Therefore, according to the scanning probe microscope 120, the sample can be observed with higher accuracy.

<Fifth embodiment>
The present embodiment is directed to a scanning probe microscope including the scanning mechanism of the second embodiment. This embodiment will be described with reference to FIG. FIG. 19 shows a scanning probe microscope 130 according to the present embodiment. 19, members denoted by the same reference numerals as those shown in FIG. 18 are similar members, and detailed description thereof is omitted.

  A scanning probe microscope 130 shown in FIG. 19 includes a laser light source 131 that emits a collimated laser beam 136, a beam splitter 132, a wave plate 133, a half mirror 135, a split detector 134, an objective lens 141, and illumination light. The illumination light source 142 which radiates | emits 144, and the condenser lens 143 which condenses the illumination light 144 are provided.

  The laser light source 131, the beam splitter 132, the wave plate 133, the split detector 134, and the half mirror 135 constitute an optical displacement sensor for optically detecting the displacement along the Z axis of the free end of the cantilever 23. These are respectively held by a lens frame (not shown). The displacement sensor constituted by these is, for example, an optical lever type displacement sensor often used in a scanning probe microscope, and a collimated laser beam 136 emitted from a laser light source 131 includes a beam splitter 132, a wave plate 133, and a half mirror. A single lens 66 provided in the scanning mechanism 60 is irradiated through 135 to form a focused spot having a diameter of about 2 μm on the cantilever 23. The reflected light passes through the single lens 66, the half mirror 135, and the wave plate 123, and is reflected by the beam splitter 132 toward the split detector 134 side. The split detector 134 outputs a displacement signal reflecting the Z displacement of the cantilever 23 to the controller 102.

  The illumination light 144 emitted from the illumination light source 142 is irradiated on the sample 116 through the condenser lens 143, the half mirror 135, and the single lens 66 and is incident on the objective lens 141. As a result, the sample 116 is observed through the inverted optical microscope.

  In the scanning probe microscope 130, the scanning mechanism 60 is used to perform high-speed scanning in the XY directions with high accuracy. Therefore, according to this scanning probe microscope 130, the observation resolution is improved and the observation time is shortened.

  Further, according to the scanning probe microscope 130, the diameter of the focused spot irradiated to the cantilever by the scanning mechanism 60 can be reduced to about 2 μm in diameter. This is effective in improving the accuracy of detecting the displacement of the cantilever 23. Therefore, according to the scanning probe microscope 130, the sample can be observed with higher accuracy.

  Further, in the scanning probe microscope 130, it is possible to observe the sample 116 with an inverted optical microscope. This leads to an improvement in operability such as observation positioning of the sample 116.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to these embodiments, and various modifications and changes can be made without departing from the scope of the present invention. Also good. The various modifications and changes described here include an implementation in which the above-described embodiments are appropriately combined.

DESCRIPTION OF SYMBOLS 10 ... Scanning mechanism, 11 ... Fixed frame, 12A, 12B ... Piezoelectric element, 13 ... XY stage, 14 ... XY movable part, 15 ... Support part, 16A, 16B, 16C, 16D ... Elastic part, 17A, 17B ... Pressing part 21 ... Piezoelectric element, 22 ... Holder, 23 ... Cantilever, 24 ... Mechanical probe, 25 ... Condenser, 26A, 26B ... Condenser lens, 27 ... Cylinder, 28 ... Optical axis, 29 ... Laser light, DESCRIPTION OF SYMBOLS 30 ... Scanning mechanism, 33 ... XY stage, 34 ... XY movable part, 35 ... Square hole, 40 ... Scanning mechanism, 41 ... Piezoelectric element, 42 ... Pseudo holder, 43 ... XY stage, 44 ... XY movable part, 50 ... Scanning Mechanism ... 53 ... XY stage 54 ... XY movable part 55 ... through hole 56 ... single lens 60 ... scanning mechanism 63 ... XY stage 64 ... XY movable part 65 ... through hole 66 ... single lens 68 ... optical axis, 70 ... scanning Structure 73 ... XY stage 74 ... XY movable part 75 ... Through hole 76 ... Single lens 77 ... Opening part 80 ... Scanning mechanism 83 ... XY stage 84 ... XY movable part 85 ... Through hole 86 DESCRIPTION OF SYMBOLS ... Single lens, 87 ... Opening part, 90 ... Scanning mechanism, 96 ... Single lens, 89 ... Optical axis, 100 ... Scanning probe microscope, 101 ... Host computer, 102 ... Controller, 103 ... Z control part, 106 ... Z piezoelectric Driver 107 107 XY piezoelectric driver 111 Laser light source 112 Split detector 113 Laser light 116 Sample 117 Sample stage 120 Scanning probe microscope 121 Laser light source 122 Beam splitter 123 ... Wave plate, 124 ... Division detector, 125 ... Laser light, 130 ... Scanning probe microscope, 131 ... Laser light source, 132 ... B Splitter, 133 ... wave plate, 134 ... division detector, 135 ... half mirror, 136 ... laser light, 141 ... objective lens, 142 ... illumination source 143 ... condenser lens, 144 ... illumination light.

Claims (25)

Cantilevers,
An XY movable portion movable in an XY direction parallel to the XY plane;
An XY actuator that scans the XY movable portion in the XY direction;
A Z actuator that is held by the XY movable part and scans the cantilever in a Z direction perpendicular to an XY plane;
A light collecting unit that is held by the XY movable unit and that makes light for detecting displacement of the cantilever incident on the cantilever,
The scanning mechanism in which the Z actuator and the light condensing unit are arranged so as to be aligned in the projection onto the XY plane.   2. The scanning mechanism according to claim 1, wherein the center of gravity of the Z actuator and the center of gravity of the light collecting unit are both within the thickness of the XY movable unit.   The Z actuator has two substantially identical stacked piezoelectric elements that can expand and contract along the Z axis, and the two stacked piezoelectric elements are respectively opposite to each other along the Z axis from the XY movable portion. The scanning mechanism according to claim 2 extending.   A holder for holding the cantilever is held at one free end of the two stacked piezoelectric elements, and a pseudo holder having substantially the same mass as the holder is held at the other free end of the two stacked piezoelectric elements. The scanning mechanism according to claim 3, which is held.   The scanning mechanism according to claim 4, wherein the light collecting unit is a single lens. The cantilever is held by the holder at an angle of 5 to 20 degrees with respect to the XY plane;
The scanning mechanism according to claim 5, wherein the single lens is held by the XY movable unit at an angle of 5 degrees to 20 degrees with respect to the Z axis.   The scanning mechanism according to claim 6, wherein the single lens has a diameter of 10 mm or less.   The scanning mechanism according to claim 7, wherein the single lens has an NA of 0.4 or more.   The scanning mechanism according to claim 2, wherein the XY movable portion has an opening provided between the Z actuator and the light collecting portion.   The Z actuator has two substantially identical stacked piezoelectric elements that can expand and contract along the Z axis, and the two stacked piezoelectric elements are respectively opposite to each other along the Z axis from the XY movable portion. The scanning mechanism of claim 9 extending.   A holder for holding the cantilever is held at one free end of the two stacked piezoelectric elements, and the other free end of the two stacked piezoelectric elements has substantially the same mass as the holder (and the cantilever). The scanning mechanism according to claim 10, wherein a pseudo holder is held.   The scanning mechanism according to claim 11, wherein the light collecting unit is a single lens. The cantilever is held by the holder at an angle of 5 to 20 degrees with respect to the XY plane;
The scanning mechanism according to claim 12, wherein the single lens is held by the XY movable portion at an angle of 5 degrees to 20 degrees with respect to the Z axis.   The scanning mechanism according to claim 13, wherein the single lens has a diameter of 10 mm or less.   The scanning mechanism according to claim 14, wherein the single lens has an NA of 0.4 or more.   The said opening part is formed between the part of the said condensing part nearest to the said Z actuator, and the said XY movable part, and has isolate | separated the said condensing part and the said XY movable part mechanically. Scanning mechanism.   The Z actuator has two substantially identical stacked piezoelectric elements that can expand and contract along the Z axis, and the two stacked piezoelectric elements are respectively opposite to each other along the Z axis from the XY movable portion. The scanning mechanism of claim 16 extending.   A holder for holding the cantilever is held at one free end of the two stacked piezoelectric elements, and a pseudo holder having substantially the same mass as the holder is held at the other free end of the two stacked piezoelectric elements. The scanning mechanism according to claim 17.   The scanning mechanism according to claim 18, wherein the light collecting unit is a single lens. The cantilever is held by the holder at an angle of 5 to 20 degrees with respect to the XY plane;
20. The scanning mechanism according to claim 19, wherein the single lens is held by the XY movable unit at an optical axis of 5 degrees to 20 degrees with respect to the Z axis.   21. The scanning mechanism according to claim 20, wherein the single lens has a diameter of 10 mm or less.   The scanning mechanism according to claim 21, wherein NA of the single lens is 0.4 or more.   A scanning probe microscope comprising the scanning mechanism according to any one of claims 1 to 22.   The scanning probe microscope according to claim 23, comprising an inverted optical microscope.   25. A scanning probe microscope according to claim 24, comprising an illumination light source for an optical microscope and an objective lens for the optical microscope, and performing illumination observation of the sample through the condensing unit with illumination light emitted from the illumination light source.

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