JP3589630B2 - Scanning probe microscope - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a scanning probe microscope such as an atomic force microscope (AFM), and particularly to a probe holding mechanism thereof.
[0002]
[Prior art]
The scanning probe microscope scans the probe or the sample by bringing the sample close to the probe arranged opposite thereto, and detects a physical quantity generated by the interaction between the probe and the sample surface to detect the sample. It measures the shape of a surface at an atomic level resolution, and corresponds to an atomic force microscope (AFM).
[0003]
The atomic force microscope measures the minute interatomic force generated between the atom at the tip of the probe and the atom on the sample surface by bringing the probe supported by a cantilever or the like close to the sample surface. Utilizes the property that is uniquely determined by the distance between the probe and the sample, and adjusts the distance between the probe and the sample so that the atomic force is constant while scanning along the sample surface. In this method, the irregular shape of the sample surface is measured by a probe or a locus of the sample in the height direction.
[0004]
While the performance of such a scanning probe microscope is sensitively influenced by the delicate shape of the probe, the probe scans within the sample surface, causing damage or deterioration of the probe. However, the deformation of the tip shape has a great adverse effect on the measurement accuracy and causes problems in the reliability and resolution of the device. Therefore, it is necessary to replace the probe before the probe deteriorates. In that case, the entire probe to which the cantilever supporting the probe is attached is exchanged.
[0005]
Conventionally, as a method of holding a probe having such a probe, a vacuum chuck type, a magnet type, a wire fixed type, and the like are disclosed in Japanese Patent No. 2990045, Japanese Patent No. 2853585, Japanese Patent Application Laid-Open No. 10-267948, This is known from Japanese Unexamined Patent Publication No. Hei 11-211734. However, these conventional methods cannot maintain the vacuum source when the vacuum source goes down, require a vacuum source to be expensive, require the sample to be affected by a magnetic field, and have a high precision of holding. Since the accuracy cannot be secured and the accuracy is compensated by the optical system after holding the probe, there is a problem that it takes time to adjust the accuracy.
[0006]
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to secure a highly accurate holding accuracy, to attach and detach a probe with high reproducibility without requiring alignment in an optical system, and to reduce the space required for a probe holding mechanism. Another object of the present invention is to provide a scanning probe microscope provided with a probe holding mechanism that does not cause a problem of holding failure when power is turned off.
[0007]
[Means for Solving the Problems]
The present invention provides a scanning probe microscope described in each of the claims as means for solving the above problems.
The scanning probe microscope according to claim 1, wherein a substantially rectangular parallelepiped probe to which a cantilever provided with a probe at the tip is accurately compensated and fixed is made to act on an inclined surface formed on the lower surface of the probe. With a probe holding mechanism that presses and holds the probe against the three clamp surfaces on the lower surface of the clamp body , it can hold the position of the probe with high accuracy, eliminating the need for alignment in the optical system after holding And
[0008]
The microscope according to claim 2, wherein a V-shaped notch is provided on the lower surface of the rectangular parallelepiped probe by cutting the probe into a V-shape at an inclination angle of about 45 ° from one ridge line of the lower surface, and the surface of the notch is levered. , The pressing force of the lever is applied equally to the three wall surfaces formed on the lower surface of the clamp body at an angle of about 45 °, and the pressing force is equal to the three surfaces by a simple mechanism. Can work.
In the microscope according to the third aspect, a sphere having a small diameter is embedded in the three wall surfaces of the lower surface of the clamp body so as to expose a part of the surface, thereby being affected by the roughness of the wall surface. In addition, the probe can be positioned and held with high accuracy by point contact.
[0009]
In the microscope according to the fourth aspect, the number of spheres embedded in the three wall surfaces is defined, and the probe is held by a total of six point contact points of six spheres and seven point contact points pressed by the lever.
In the microscope according to the fifth aspect, the configuration of the probe holding mechanism is embodied, and the probe can be held by rotating the lever, so that a space for the holding portion can be saved, and a large number of spare probes are provided for measures against deterioration. Even when arranged, it is easy to take out.
[0010]
In the microscope according to the sixth aspect, the drive mechanism for driving the lever includes an air cylinder for driving the lever from the locked state to the release position, and a pressing rod urged by a spring for returning the lever to the locked position. The probe is held on the clamp body by spring pressure.
In the microscope according to claim 7, the tip of the lever has a hemispherical shape, and the lever presses the probe with point contact, so that the pressing force acts on the probe efficiently.
[0011]
The microscope according to claim 8, further comprising a fine adjustment mechanism capable of finely adjusting a probe of the probe in the X, Y, and Z directions. When detecting, the effect of the moment of inertia is reduced by reducing the size and weight of the fine adjustment mechanism, and measurement accuracy can be improved.
In the microscope according to the ninth aspect, the contact portion of the lever and the clamp body that comes into contact with the probe is formed of a magnetic material, so that dust, particles, and the like generated by the contact with the probe are removed from the magnetic material. To prevent falling and scattering.
[0012]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a probe holding mechanism of a scanning probe microscope according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a side view of a probe holding mechanism of a scanning probe microscope according to an embodiment of the present invention. FIG. 1 shows a relationship between a probe holding mechanism A, a probe B immediately before being held by the probe holding mechanism A, and an objective lens C of a microscope. In this figure, the objective lens C appears to be arranged at an angle, but in reality, the objective lens C is arranged vertically, and the probe B is held at an angle to this. The holding mechanism A is fixed to the support D with bolts or the like.
[0013]
As shown in FIGS. 1 to 4, the holding mechanism A basically includes a clamp body 1, a rotating shaft 2 of a lever, a lever member 3, and a driving mechanism 4 for rotating the lever member 3. The clamp body 1 has a vertically penetrating hole 11 for inserting the rotating shaft 2, a receiving portion 12 of a thrust bearing 22 whose side surface is cut in a U shape, and three surfaces of the probe B. A concave portion 13 is formed in the lower surface for receiving the contact so as to abut, and the concave portion 13 constitutes a clamp surface. The thrust bearing 22 arranged in the receiving portion 12 of the clamp body 1 is provided with a lock screw 24 for preventing the inserted rotating shaft 2 from moving in the thrust direction. The concave portion 13 forming the clamp surface formed on the lower surface of the clamp body 1 has a bottom wall 13a for contacting the probe B and two side walls 13b and 13c, and the other two side walls are removed. I have. A sphere 14 made of sapphire (alumina) having a diameter of about 0.5 mm is formed on the bottom wall 13a of the bottom wall and the side wall so as to make a point contact with the probe B, with a part of the surface exposed. It is embedded in three places, two places in the longitudinal side wall 13b, and one place in the other side wall 13c.
[0014]
A lever 21 having a hemispherical tip is provided at the tip of the rotating shaft 2 that passes through the inside of the clamp body 1. The rotating shaft 2 is rotatably supported by radial bearings 23 disposed above and below a thrust bearing 22 of the clamp body 1. Therefore, with the rotation of the rotation shaft 2, the lever 21 rotates between the position where the probe B is locked and the position where the lock is released, for example, about 90 ° as shown in FIG. The rotating shaft 2 passes through a lever member 3 mounted on the upper part of the clamp body 1 and described later in detail.
[0015]
The lever member 3 has a hole 31 into which the rotating shaft 2 is inserted, a slit portion 32 connected to the hole, and a bifurcated shape provided at the upper and lower portions for supporting the pressed member 34. A bearing 33 is formed. The slit portion 32 is provided with a tightening screw 35 for tightening the rotating shaft 2. By tightening the screw 34, the lever member 3 and the rotating shaft 2 are firmly fixed.
[0016]
As shown in FIG. 3, a drive mechanism 4 for rotating the lever member 3 is attached to the support D. The driving mechanism 4 presses the pressed member 34 pivotally supported by the lever member 3 to rotate the lever member 3 and move the lever 21 to the release position from the lock as shown in FIG. The air cylinder 41 and the lever member 3 are pressed against the pressed member 34 by a spring force on a side opposite to the air cylinder 41 with respect to the lever member 3 to rotate the lever member 3 in a direction opposite to the rotation by the air cylinder 41, and the lever 21 is locked. And a pressing rod 42 for moving the As shown in FIG. 5, the pressing rod 42 is slidably inserted into the adjusting screw 43, and a spring 44 is arranged between the pressing rod 42 and the adjusting screw 43. Therefore, the turning force of the spring 44 can be adjusted by turning the nut of the adjusting screw 43. Reference numeral 45 denotes a set screw for fixing the adjustment screw 43.
[0017]
FIG. 6 shows a probe B held by the holding mechanism A. The probe B includes a cantilever 6 provided with a probe 5 and a cantilever holder 7 to which the cantilever 6 is attached by bonding or the like. On the lower surface of the tip of the cantilever holder 7, a groove 71 for improving the flow of an adhesive for bonding the cantilever 6 is formed, and at an angle of about 45 ° from one ridge line of the lower surface of the rectangular parallelepiped portion. A V-shaped notch 72 cut in a V-shape is formed. Therefore, the surface 72 a of the V-shaped notch 72 is equally inclined by about 45 ° with respect to the upper surface and the two side surfaces of the cantilever holder 7. When the cantilever holder 7 is held by the clamp body 1 described above, the lever 21 enters the V-shaped notch 72 and presses a surface 72 a of about 45 ° of the notch 72, whereby the upper surface of the cantilever bolder 7 is formed. And the two side surfaces (the side surface on which the notch portion 72 is not formed and the rear side surface) are respectively provided on the bottom wall and the six spheres 14 embedded in the two side walls of the concave portion 13 forming the clamp surface of the clamp body 1. Abuts and acts with equal force on the clamping surface. Further, the contact portion between the lever 21 and the clamp body 1 that contacts the probe B may be formed of a magnetic material. As a result, dust, particles, and the like generated due to the contact with the probe B do not adhere to the magnetic material portion, and do not fall and scatter.
[0018]
7, 8, and 9 show a fine adjustment mechanism 8 for finely adjusting the probe of the probe B in the X, Y, and Z directions. The fine adjustment mechanism 8 is provided between a support D that fixes the probe holding mechanism A and a holder 9 that holds the objective lens C, between which the X slider 81 and the Y slider 82 Is interposed. The holder 9 and the X slider 81 are slidable in the X direction and fitted so as to be restricted in the Y and Z directions. The holder 9 is provided with a long hole 9a in the Y direction, and the X slider 81 is provided with an inclined long groove 81a slightly inclined with respect to the long hole 9a, and the cylindrical shaft 10a extends over the long hole 9a and the inclined long groove 81a. Are located. An adjusting screw 9d is arranged on the holder 9 so as to cross the elongated hole 9a in the longitudinal direction. The adjusting screw 9b is orthogonal to the cylindrical shaft 10a and is screwed to the cylindrical shaft 10a so as to penetrate therethrough. Therefore, when the cylindrical shaft 10a moves in the Y direction by the rotation of the adjusting screw 9d, the cylindrical shaft 10a reaches the inclined elongated groove 81a of the X slider 81, and the X slider 81 is constrained in the Y direction. To slide. Thereby, fine adjustment in the X direction can be performed.
[0019]
Similarly, the X slider 81 and the Y slider 82 are slidable in the Y direction and fitted so as to be restricted in the X and Z directions. The X slider 81 has an elongated hole 81b in the Z direction, and the Y slider 82 has an inclined elongated groove 82b slightly inclined with respect to the elongated hole 81b, and extends over the elongated hole 81b and the inclined elongated groove 82b. A cylindrical shaft 10b is arranged. On the X slider 81, an adjusting screw 81d is disposed to traverse the longitudinal direction of the elongated hole 81b, and the adjusting screw 81d is orthogonal to the cylindrical shaft 10b and is screwed to the cylindrical shaft 10b so as to penetrate therethrough. I have. Therefore, when the cylindrical shaft 10b moves in the Z direction due to the rotation of the adjusting screw 81d, the Y slider 82 is restricted in the Z direction because the cylindrical shaft 10b reaches the inclined elongated groove 82b of the Y slider 82, so that Y Slide in the direction. This allows fine adjustment in the Y direction.
[0020]
Similarly, the Y slider 82 and the support D that fixes the probe holding mechanism A are slidable in the Z direction and fitted so as to be restricted in the X and Y directions. A long hole 82c is formed in the Y slider 82 in the Y direction, and a slanted long groove Dc is provided in the support D at a slight angle to the long hole 82c, and extends over the long hole 82c and the slanted long groove Dc. A cylindrical shaft 10c is disposed. On the Y slider 82, an adjusting screw 82d is disposed to traverse the longitudinal direction of the elongated hole 82c. The adjusting screw 82d is orthogonal to the cylindrical shaft 10c, and is screwed to the cylindrical shaft 10c so as to penetrate therethrough. I have. Therefore, when the cylindrical shaft 10c moves in the Y direction by the rotation of the adjusting screw 82d, the cylindrical shaft 10c reaches the oblong elongated groove Dc of the support D, and the support D is restrained in the Y direction. Slide in the direction. This allows fine adjustment in the Z direction.
[0021]
The holder 9 and the X slider 81, the X slider 81 and the Y slider 82, and the Y slider 82 and the support D are supported by bolts or the like.
As described above, since the fine adjustment mechanism 8 for the X, Y, and Z directions of the probe tip of the scanning probe microscope of the present invention can be made compact and lightweight, the micro displacement is detected by the optical method of this microscope. In this case, the influence of the moment of inertia can be reduced, and the measurement accuracy can be improved.
[0022]
The operation of the probe holding mechanism A configured as described above will be described. In an initial state in which the probe B is not held by the probe holding mechanism A, the lever member 3 and the rotation shaft 2 are rotated by about 90 ° counterclockwise by the air cylinder 41 against the urging force of the spring 44. As a result, the lever 21 faces the longitudinal direction in the released state. In this state, the probe B is carried to a set position as shown in FIG. 1 by a supply mechanism (not shown), and is arranged near the lower surface of the clamp body 1. Next, the pressing force by the air cylinder 41 is released, and the lever member 3 and the rotating shaft 2 are rotated about 90 ° clockwise by the urging force of the spring 44, whereby the lever 21 is moved as shown in FIG. The probe B is rotated to a lock position (a direction perpendicular to the longitudinal direction), and its tip comes into contact with the surface of a V-shaped notch 72 formed in the cantilever boulder 7, which is pressed to clamp the probe B. It is held on the lower surface of the main body 1. Therefore, the urging force of the spring 44 is the holding force of the probe B.
The probe B is released from the holding mechanism A by operating the air cylinder 41 against the urging force of the spring and rotating the lever 21 counterclockwise by approximately 90 °.
[0023]
As described above, in the probe holding mechanism of the scanning probe microscope of the present invention, the locking and releasing of the probe is performed by rotating the lever, so that the space of the holding mechanism can be saved, and the probe is brought into point contact. The probe can be automatically replaced with high accuracy without being affected by the surface roughness of the holding surface. Further, since no vacuum is used, there is no danger of vacuum down, and since there is no magnetic force, there is no influence of magnetism.
[Brief description of the drawings]
FIG. 1 is a side view of a probe holding mechanism of a scanning probe microscope according to an embodiment of the present invention.
FIG. 2 is a front view of a probe holding mechanism of the scanning probe microscope according to the embodiment of the present invention.
FIG. 3 is a top view of a probe holding mechanism of the scanning probe microscope according to the embodiment of the present invention.
FIG. 4 is a bottom view of a probe holding mechanism of the scanning probe microscope according to the embodiment of the present invention.
FIG. 5 is a diagram showing a driving mechanism of the probe holding mechanism of the present invention.
FIG. 6 is a side view and a plan view of a probe used in the probe holding mechanism of the present invention.
FIG. 7 is a front view of a fine adjustment mechanism used in the probe holding mechanism of the present invention.
FIG. 8 is a side view of the fine adjustment mechanism of FIG. 7;
FIG. 9 is a plan view of the fine adjustment mechanism of FIG. 7;
[Explanation of symbols]
A ... Probe holding mechanism B ... Probe C ... Objective lens 1 ... Clamp body 14 ... Ball 2 ... Rotating shaft 21 ... Lever 3 ... Lever member 4 ... Drive mechanism 41 ... Air cylinder 42 ... Press rod 43 ... Adjustment screw 44 ... Spring 8 Fine adjustment mechanism

Claims (9)

The sample and the probe are placed in close proximity to each other, and by scanning either one of them, the physical quantity generated by the interaction between the probe and the sample surface is detected, and the shape of the sample surface is measured with atomic resolution. Scanning probe microscope
A substantially rectangular parallelepiped probe having a cantilever provided with a probe at the tip fixed thereto and having an inclined surface on a lower surface cut at a predetermined angle from one ridge line on the lower surface,
A probe main body including a probe body having three clamp surfaces for holding the probe, and a lever for pressing the probe on the three clamp surfaces,
A scanning probe microscope , wherein the probe is held by applying the lever to an inclined surface of the probe and pressing the probe against the three clamp surfaces . The clamp surfaces of the clamp body are three wall surfaces formed on the lower surface of the clamp body, and the pressing forces generated by the lever equally act on the three wall surfaces at angles of about 45 °. 2. The scanning type according to claim 1, wherein the inclined surface formed on the lower surface of the substantially rectangular parallelepiped probe is formed by a V-shaped notch cut at an inclination angle of about 45 °. Probe microscope. The scanning probe microscope according to claim 2, wherein spheres having a small diameter are embedded in three wall surfaces formed on a lower surface of the clamp body so that the surfaces are exposed. Of the three walls on the lower surface of the clamp body, three small diameter spheres are embedded on the bottom wall, two on the longitudinal side wall, and one on the rear side wall so as to expose a part of the surface. The scanning probe microscope according to claim 3, wherein the scanning probe microscope is provided. The probe holding mechanism includes the clamp body that receives the probe, a rotation shaft to which the lever is attached, a lever member that rotates the rotation shaft, and a drive mechanism that acts on the lever member. The scanning probe microscope according to claim 1, wherein: The drive mechanism has an air cylinder for driving the lever to a release position from a locked state, and a pressing rod urged by a spring for returning the lever to the lock position. The scanning probe microscope according to claim 5, wherein The scanning probe microscope according to claim 1, wherein a tip of the lever is hemispherical. The scanning probe microscope according to any one of claims 1 to 6, further comprising a fine adjustment mechanism capable of finely adjusting a probe of the probe in X, Y, and Z directions. . The scanning probe microscope according to any one of claims 1 to 4, wherein a contact portion of the lever and the clamp body that contacts the probe is formed of a magnetic material.

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