JP2000258332A - Cantilever for detecting normal force for atomic force microscope - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a normal force without being affected by a torsional deflection by improving a torsional rigidity of a cantilever for detecting the normal force for an AFM without affecting a flexural rigidity. SOLUTION: A plurality of parallel leaf springs 3 in parallel to a surface of a sample 1 to be tested are set via a space to be opposite to each other, thereby constituting a cantilever ? body 2. A base end of the body is fixed to a base 7 mounted to an AFM, and a block-shaped head 4 is set to a leading end part of the cantilever body 2. A probe 5 is set to a face of the head 4 directed to the sample 1, so that a shift or an angle of the cantilever body 2 can be detected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cantilever for detecting a vertical surface force or a vertical force used in an atomic force microscope (AFM) for measuring a surface shape or a vertical force of a sample. The present invention relates to a cantilever for detecting a vertical force capable of realizing an invariable contact point of a tip portion of a probe that contacts the probe.

[0002]

2. Description of the Related Art A conventional cantilever for detecting a vertical force for an AFM generally has a cantilever body 11 attached to a base portion of the AFM having a single leaf spring structure as shown in FIG. The probe 12 is attached to the tip. In such a conventional cantilever, if the bending rigidity is reduced to improve the vertical force detection sensitivity, the torsional rigidity is also reduced.
Due to the torsional displacement of the probe 12 as shown in FIG.
There is a problem that the probe tip position with respect to 0 changes, making it difficult to accurately measure the shape. When the focus curve is to be measured, as shown in FIGS. 5A and 5B, the position at which the probe 12 contacts the sample 10 changes depending on the size of the focus curve. Measurement was not possible. Similarly, when the vertical load was changed, the contact position of the probe also changed, and measurement under the same conditions could not be performed.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the technical problem thereof is that the twisting is basically performed without affecting the bending rigidity of the cantilever body. An object of the present invention is to provide a cantilever for detecting a normal force for an AFM, which has improved rigidity and can detect a normal force in a state hardly affected by torsional deformation. Another technical problem of the present invention is to provide a cantilever for normal force detection for an AFM, which can realize high-precision measurement of a shape and an invariable contact point of a probe tip portion in contact with a sample. is there.

[0004]

According to the present invention, there is provided a cantilever for detecting a vertical force for an AFM according to the present invention, comprising a plurality of mutually parallel leaf springs oriented in parallel to a surface of a test sample. A cantilever body is formed by opposing and spaced apart from each other, and by mutually constraining both ends of the leaf springs, and a base end thereof can be fixed to a base attached to the AFM. , A block-shaped head is provided, a probe is provided on a surface of the head facing the sample side, and a displacement or angle detecting means is provided on the cantilever main body.

In the cantilever for detecting a vertical force for an AFM having the above-described structure, when a sample pushes a probe vertically upward, the probe is displaced upward in parallel with the head without changing the angle. When the cantilever for vertical force detection is mounted on a displacement detection type AFM, displacement detection means for detecting the vertical displacement of the surface on the side opposite to the probe above the head using a laser beam or the like is provided. Provided, whereby the displacement is detected. When the cantilever for detecting a vertical force is attached to an angle detection type AFM, an angle detection means for detecting an angle near the center of the leaf spring using a laser beam or the like is provided, and the angle is detected by the angle detection means . Further, the cantilever body having the above-described structure can realize a high-precision measurement of a vertical force and a constant contact point of a probe tip portion that comes into contact with a sample.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 and FIG.
4 shows an embodiment of a cantilever for detecting a vertical force for FM. In the cantilever for detecting a vertical force of this embodiment, a cantilever main body 2 is formed by arranging two parallel leaf springs 3 facing in parallel with the surface of a test sample 1 at appropriate intervals. The distal end and the proximal end of the cantilever body 2 are mutually restrained, that is, the proximal end is integrally fixed to the base 7 attached to the AFM, and the cantilever body 2 including the leaf spring 3 is fixed.
Are joined by a block-shaped head 4,
A probe 5 is provided on the surface of the head 4 facing the sample 1 side.

Accordingly, as shown in FIG. 2, when the surface of the sample 1 is displaced vertically upward and pushes the probe 5, the probe 5 is displaced upward and parallel with the head 4 without changing the angle. Thereby, the contact state between the probe 5 and the sample 1 irrespective of the magnitude of the load is maintained. Similarly, when the sample 1 moves in the horizontal direction, the head 4 does not change its angle.

When the cantilever for detecting a vertical force is an AFM of a displacement detection type and the cantilever body 2 is attached to a base 7 attached to the cantilever, the surface of the head 4 opposite to the probe 5 is a reflecting surface. A displacement detecting means such as a photodetector (not shown) for detecting the vertical displacement of the head 4 using a laser beam or the like is provided, whereby the displacement of the head 4 can be detected. When the cantilever for vertical force detection is an angle detection type AFM and the cantilever body 7 is attached to the base 7 attached thereto, the angle near the center of the leaf spring 3 is detected using a laser beam or the like. An angle detecting means such as a photodetector is provided to detect the angle.

Further, the torsion displacement of the probe 12 as shown in FIG. 4 and FIG.
Since the position of the tip of the probe 12 does not change with respect to 0, it is possible to realize high-precision measurement of vertical force. A constant contact point at the tip of the probe 5 that comes into contact with the probe 5 can be realized, and measurement can always be performed under the same conditions.

In the cantilever for detecting a vertical force for the AFM shown in FIG. 1, the cantilever body 2 is formed by arranging two parallel leaf springs 3 at an appropriate interval to face each other. , The number of the leaf springs 3 is 3
More than one sheet may be connected by a block-shaped head 4. Further, in order to improve the sensitivity of displacement and angle detection of the head 4, the leaf spring 3 constituting the head 4 and the cantilever main body 2 can be coated with metal.

[0011]

According to the vertical force detecting cantilever for AFM of the present invention described in detail above, at least two parallel leaf springs are opposed to each other with a space therebetween, and the tip and the base are restrained. The probe is displaced in the vertical direction without changing the angle with the head because the cantilever body is configured, and the torsional rigidity is improved without affecting the bending rigidity of the cantilever body, and the probe is hardly affected by torsional deformation. Normal force can be detected. In addition, high-precision measurement of the shape and a constant contact point at the tip of the probe that comes into contact with the sample can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of an embodiment of a cantilever for detecting a vertical force for an AFM according to the present invention.

FIG. 2 is a perspective view showing a use state of the embodiment.

FIG. 3 is a perspective view showing a configuration example of a conventional cantilever for detecting a vertical force.

FIG. 4 is a perspective view showing an operation example of the cantilever for vertical force detection of FIG. 3;

FIGS. 5A and 5B are side views showing an outline of an operation example of a conventional cantilever for detecting a vertical force.

[Explanation of symbols]

 Reference Signs List 1 sample 2 cantilever body 3 leaf spring 4 head 5 probe 7 base

Claims (1)

[Claims] 1. A cantilever body comprising a plurality of parallel leaf springs facing in parallel to a surface of a test sample, spaced apart from each other, and mutually constraining both ends of the leaf springs. In addition, the base end can be fixed to the base attached to the atomic force microscope, and a block-shaped head is provided at the tip of the cantilever body, and the probe is attached to the surface of the head facing the sample side. Provided, displacement / angle detection means provided on the cantilever body,
A cantilever for detecting a vertical force for an atomic force microscope.