JPH09222431A - Force microscope apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a force microscope apparatus whose configuration can be made easy even when an optical lever-type displacement detection optical system is used. SOLUTION: A scanning mechanism 1, an approach and retreat mechanism 5, an optical microscope 11, a laser light source 6 and a photodetector 7 are attached to a support structure 12. A reflection member 10 which comprises a reflecting face 10a is attached to the rear of a probe 4 at a cantilever 3. When the angle of the reflecting face 10a is selected properly, the laser light source 6 and the photodetector 7 can be arranged in positions which are deviated from the opticap path of the optical microscope 11, and the configuration of an apparatus can be made easy.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a force microscope apparatus using an optical microscope and an optical lever type displacement detecting optical system.

[0002]

2. Description of the Related Art In a force microscope, a probe with a sharp tip is brought close to a sample to the order of nanometer (nm), and the atomic force generated between the probe and the sample at that time is measured. This is a device that measures the shape of the sample surface at the atomic level. Such a force microscope apparatus uses a lever called a cantilever having an extremely low spring constant, and detects an atomic force acting on a probe provided at the tip of the cantilever as a deflection amount of the cantilever. The deflection amount of the cantilever is detected by a displacement detection optical system called an optical lever method.

FIG. 2 is a schematic configuration diagram of a conventional atomic force microscope apparatus using an optical lever system. In this figure, 1 is a sample to be measured, 2 is a scanning mechanism on which the sample 1 is placed and which is scanned two-dimensionally (X-axis and Y-axis directions), 3
Is a cantilever, 4 is a probe attached to the tip of the cantilever 3, and 5 is a cantilever 3 fixed and displaced in the vertical direction (Z-axis direction) in the figure to move the probe 4 toward and away from the sample 1. -It is a retracting mechanism. Reference numeral 6 is a laser light source, and 7 is a photodetector for receiving the light from the laser light source 6 reflected by the back surface of the cantilever. Reference numeral 8 denotes a support structure that supports the scanning mechanism 2, the approaching / retracting mechanism 5, the light source 6, and the photodetector 7. An optical lever type displacement detection optical system including a laser light source 6, a reflecting surface on the back surface of the cantilever 3, and a photodetector 7 is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-187862.

When the approaching / retracting mechanism 5 is driven to bring the probe 4 closer to the sample 1 to the nanometer range, an atomic force acts and the cantilever 3 is flexibly deformed. The flexural deformation of the cantilever 3 can be detected as a position change of the reflected light on the photodetector 7. This change in position is magnified by the lever principle (optical lever method) as compared with the amount of flexural deformation of the cantilever 3 to detect a minute displacement of the probe 4 on the order of nanometers. Sample 1 by scanning mechanism 7
By scanning in the X and Y directions and checking the detection signal of the photodetector 7, the deflection amount of the cantilever 3, and thus the surface shape of the sample 1 can be obtained.

[0005]

The measuring range of such a force microscope apparatus is several tens of μm at the maximum. For this reason,
For example, when checking the abnormality of the details of one pit in a large sample such as an optical disk, it is impossible to visually align the tip of the probe with such a minute portion. Therefore, the force microscope apparatus is usually provided with the scanning mechanism 2 for moving the sample and an optical microscope having a field of view larger than the measurement range of the force microscope apparatus.
In this force microscope apparatus, the cantilever 3 supporting the probe 4 can be observed by the optical microscope, so that the probe 4 can be easily aligned with the target position on the sample 1. However, in the case of using the optical lever type displacement detection optical system shown in FIG. 2, the observation optical path of the optical microscope and the optical lever type displacement detection optical system must be arranged substantially coaxially, and the structure of the force microscope apparatus is configured. Was making it difficult.

An object of the present invention is to solve the above-mentioned problems in the prior art and to use an optical lever type displacement detection optical system,
An object of the present invention is to provide a force microscope device that can be easily configured.

[0007]

In order to achieve the above object, the present invention comprises a mechanism for mounting a sample, an optical microscope arranged to face this mechanism, a probe, and a tip having the above-mentioned structure. A cantilever arranged in the optical path of the optical microscope, a displacement detection optical system including a light source and a photodetector for detecting the displacement of the cantilever, and a displacement mechanism for bringing the tip of the cantilever into and out of contact with the sample. In the force microscope apparatus, a reflecting member having a reflecting surface at a predetermined angle with respect to the back surface of the cantilever is provided on the back surface of the cantilever.

[0008]

By providing a reflecting surface at a predetermined angle on the back surface of the cantilever, the light from the light source is reflected according to the predetermined angle, and the reflected light is made incident on the photodetector. The deflection deformation amount of the cantilever can be detected by the incident position of the reflected light on the photodetector. By providing the reflecting surface, the light source and the photodetector can be arranged at positions separated from the optical path of the optical microscope, and the configuration of the force microscope apparatus is significantly facilitated.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a schematic configuration diagram of a force microscope apparatus according to an embodiment of the present invention. In this figure, the same or equivalent parts as those shown in FIG. 2 are designated by the same reference numerals. Reference numeral 10 denotes a reflecting member attached to the back surface of the cantilever 3, and 10 a denotes a reflecting surface of the reflecting member 10. In the illustrated example, the reflecting surface 10a forms an angle of 45 degrees or more with the back surface of the cantilever 3. 1
Reference numeral 1 denotes an optical microscope, which is arranged at a position where the probe 4 is inserted in the optical path thereof. Reference numeral 12 denotes a support structure, which includes a support portion 12a for supporting the optical microscope 11, a support portion 12b for supporting the approaching / retracting mechanism 5, a support portion 12c for supporting the laser light source 6, and a support portion 12d for supporting the photodetector 7. I have it. The support portion 12c and the support portion 12d are arranged on the opposite side to the support portion 12b, and the support portion 12d is the support portion 1
It is located above 2c. Reflective surface 1 of reflective member 10
0a is selected as an angle for reflecting the laser light of the laser light source 6 to the photodetector 7.

Next, the operation of this embodiment will be described. First,
The focus of the optical microscope 11 is adjusted to capture the cantilever 3 and the probe 4 in the field of view, and thereafter, the scanning mechanism 2 is driven based on the captured optical microscope image, and the measurement target portion of the sample 1 is probed 4 To match. This completes the measurement system. During the measurement, the amount of flexural deformation of the cantilever 3 due to the interatomic force appears as a change in the angle of the reflection surface 10a of the reflection member 10, and the reflection angle of the laser light from the laser light source 6 at the reflection surface 10a changes in accordance with the change in the angle. Changes,
The incident position on the photodetector 7 changes. After all, the amount of flexural deformation of the cantilever 3 can be detected by the incident position of the laser light on the photodetector 7.

As described above, in this embodiment, the reflecting member is provided on the back surface of the cantilever, and the reflecting surface is selected so that the light from the laser light source is incident on the photodetector. The light source and the photodetector can be placed out of the optical path of the optical microscope. Since the displacement detection optical system can be configured by appropriately selecting the angle of the reflecting surface according to the arrangement position of the laser light source and the photodetector, the degree of freedom in selecting the arrangement position of the laser light source and the photodetector. Is significantly increased, and the configuration of the device can be facilitated.

[0012]

As described above, in the present invention, the reflecting member is provided on the back surface of the cantilever, and the reflecting surface is selected so as to allow the light from the light source to enter the photodetector. , The optical lever type displacement detection optical system can be arranged at a position deviated from the optical path of the optical microscope, and the degree of freedom in selecting the arrangement positions of the light source and the photodetector is increased, and the device configuration can be simplified. it can.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a force microscope apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a schematic configuration of a conventional force microscope apparatus.

[Explanation of symbols]

 1 sample 2 scanning mechanism 3 cantilever 4 probe 5 approaching / retracting mechanism 6 laser light source 7 photodetector 10 reflecting member 10a reflecting surface 11 optical microscope 12 supporting structure 12a, 12b, 12c, 12d supporting portion

Claims (2)

[Claims] 1. A mechanism for mounting a sample, an optical microscope arranged to face the mechanism, a cantilever having a probe and a tip arranged in an optical path of the optical microscope, and displacement of the cantilever. In a force microscope apparatus provided with a displacement detection optical system including a light source and a photodetector for detecting, and a displacement mechanism for bringing the tip of the cantilever into and out of contact with the sample, on the back surface of the cantilever, with respect to this back surface. And a reflecting member having a reflecting surface of a predetermined angle. 2. The force microscope apparatus according to claim 1, wherein the predetermined angle of the reflecting surface is an angle that allows both incident light and reflected light to exist on one side of the optical path of the optical microscope.