JPH06258066A - Infinitesimal part force measuring apparatus - Google Patents

Abstract

PURPOSE:To accurately detect an infinitesimal part by providing a non-contact displacement meter having a large measuring area at an opposite side to a probe through a beam. CONSTITUTION:When a sample 3 is made to approach a probe 1 by a roughly moving mechanism 11 up to several Angstrom , a force is operated between mostly approached atoms of both surface atoms, a beam 2 is displaced, and it is detected by non-contact displacement measuring means 4. A Z-axis piezo element 9 is so driven by a controller 12 as to hold the change constant, and a gap between the probe 1 and the sample 3 is maintained constant. When it is scanned in two dimensions by X-axis, Y-axis piezo elements 7, 8 while holding this state, the element 9 is varied based on a surface shape of the sample 3 to obtain a three-dimensional shape of the sample surface, and a fine structure can be displayed on a display unit 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring a three-dimensional cross-sectional shape of a minute area, and more particularly to an apparatus for measuring a force in a minute area suitable for measuring an insulator surface.

[0002]

2. Description of the Related Art Conventionally, regarding the detection of force in a minute area, Physical, Review, Later 56, (1986) No. 9
Pages 30 to 933 (Phys. Rev, Lett, 56, (1
986) pp 930-933).

[0003]

As shown in FIG. 2, the above-mentioned prior art is provided with a sharp probe 1 at the tip of a beam (plate member) 2 which is a fulcrum at one end by a beam support 5. As the sample 3 approaches, the beam 2 is displaced by the atomic force, and the displacement causes a constant tunneling current to flow like a scanning tunneling microscope (STM) to make the gap between the beam 2 and the probe 14 constant. Measure by keeping. By using such a non-contact gap measuring method, a force is converted into a displacement, and the displacement is measured to detect the force in a minute region.

This technique does not consider the rigidity of the probe 1 for force detection. Further, the stability for displacement measurement, that is, the measurement error due to the surface roughness of the measurement surface of the beam 2 is not taken into consideration, and there is a problem in detection accuracy.

[0005]

The above object is to provide a beam member having two supporting portions, a probe fixed to the beam member and located between the two supporting portions, and a sample facing the probe. A sample table to be arranged, a first moving means for relatively moving the space between the probe and the sample, a second moving means for relatively moving the probe two-dimensionally along the sample surface, And a measuring means for measuring the displacement of the beam member due to the force acting between the needle and the sample.

Preferably, the three-dimensional cross-sectional shape is measured using a control device that operates the second moving means while controlling the first moving means so as to keep the displacement of the beam member constant.

In order to improve the rigidity of the beam 2 in FIG. 2 as described above, at least both ends of the beam 2 are fixed and the probe 1 is installed in the central portion. It is also desirable to provide a non-contact displacement measuring means capable of measuring a minute displacement in a large area in order to prevent a minute displacement measurement error due to surface unevenness in the displacement measurement of the beam 2.

[0008]

The beam 2 which is supported at both ends has a degree of freedom in the axial direction of the probe because it is supported at both ends and can prevent movement such as twisting. Therefore, the rigidity of the beam 2 is improved. Further, the non-contact displacement measuring device having a large-area displacement detecting portion can perform measurement without being affected by the unevenness of the surface of the beam 2 and the arrangement of atoms.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows an example in which the present invention is applied to a three-dimensional shape measuring instrument for a minute area.

In FIG. 1, the force detecting portion has both ends of a beam 2 supported by supports 5, and a diamond-made probe 1 having a very sharp tip is installed in the center of the beam 2, and a beam 2 is used to search. A non-contact displacement gauge 4 such as a capacitance displacement gauge is provided on the side opposite to the needle 1.

The sample 3 is mounted on a sample table 6 on a three-dimensional fine movement mechanism provided on the coarse movement mechanism 11. The three-dimensional fine movement mechanism has a tri-pot type configuration in which X-axis, Y-axis, and Z-axis piezo elements 7, 8 and 9 are installed on a pedestal 10 as shown in the figure. Further, the displacement due to the force is detected, the force is made constant, that is, the Z-axis piezo element 9 is controlled so as to make the displacement constant, and the two-dimensional scanning or the coarse movement to bring the sample 3 closer to the probe 1 is performed. Mechanism 1
1 has a control device 12 for controlling 1. The display device 13 three-dimensionally displays the three-dimensional structure of the sample.

If the beam 2 is made of silver having a thickness of 10 μm, a width of 0.5 cm, and a length of 5 cm, a force of about 10 ⁻¹² N (Newton) causes a change of about 1 Å. On the other hand, as the non-contact displacement measuring means 4, a capacitance displacement meter having a large area to be measured or an optical lever type optical displacement measuring device is used. Further, the coarse movement mechanism 11 uses a scale insect mechanism, a screw type or a reduction displacement mechanism.

A sample 3 is attached to the probe 1 by the coarse movement mechanism 11 described above.
When approaching to each other and approaching to a few Å, a force acts between the atoms closest to each other on both surface atoms, and the beam 2 is displaced, which is detected by the non-contact displacement measuring means. The controller 12 drives the Z-axis piezo element 9 so as to keep this change constant,
The gap between the probe 1 and the sample 3 is kept constant. When two-dimensional scanning is performed with the X-axis and Y-axis piezo elements 7 and 8 while maintaining this state, the Z-axis piezo element changes based on the surface shape of the sample 3 to obtain the three-dimensional shape of the sample surface. A fine structure can be displayed at 13. Actual atomic force is 10
^It is said to be ^-9 to 10 ^-10 N, and the beam structure and displacement meter described above are sufficient to observe the atomic structure of the surface.

Although the present embodiment is structured so as to be influenced by the construction force, it may be structured so that it is rotated by 90 ° and is not influenced by gravity. Further, a minute mechanism or a coarse movement mechanism may be installed on the sample side or the force measuring section. The probe 1 is preferably made of a material having a high hardness other than diamond, and it is important to make the tip sharp, and it is desirable to manufacture it by ion etching, chemical etching, or precision processing technology. Furthermore, if the probe is made of something other than an insulator, it can be used as a scanning tunneling microscope.

This system can obtain a better image by being combined with a computer for data processing.

[0016]

According to the present invention, the mechanical rigidity of the probe is increased, and the influence of force is accurately converted into displacement. Further, since the non-contact displacement measuring means having a large measuring area is used, it is possible to remove the influence of the unevenness on the surface of the beam, and therefore it is possible to detect the minute portion of the minute portion with high accuracy. Also, by applying it to a three-dimensional shape measuring instrument, all materials can be measured. Moreover, since the above-mentioned non-contact displacement measuring means normally operates stably in the atmosphere, it is not necessary to operate in a vacuum unlike the STM.

[Brief description of drawings]

FIG. 1 is a main part configuration diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a main part configuration diagram showing a principle configuration of a conventional force measuring device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Probe, 2 ... Beam, 3 ... Sample, 4 ... Non-contact displacement measuring means with a large measurement area, 5 ... Beam support tool, 6 ... Sample stand, 7
... X-axis piezo element, 8 ... Y-axis piezo element, 9 ... Z-axis piezo element, 10 ... Pedestal, 11 ... Coarse movement mechanism, 12 ... Control circuit, 13 ... Display means.

Claims (5)

[Claims] 1. A beam member having two supporting parts, a probe fixed to the beam member and located between the two supporting parts, and a sample stand for arranging a sample facing the probe. First moving means for relatively moving the space between the probe and the sample, second moving means for relatively moving the probe two-dimensionally along the sample surface, the probe and the sample And a measuring means for measuring the displacement of the beam member due to the force acting between 2. The micro-part force measuring device according to claim 1, further comprising a control device for operating the second moving means while controlling the first moving means so as to keep the displacement of the beam member constant. 3. The micro force measuring device according to claim 2, further comprising means for obtaining shape information of the surface of the sample from the operation of the first moving means, and display means for displaying the shape information. 4. A beam member having two supporting portions and a probe fixed to the beam member and positioned between the two supporting portions are used, and a sample is arranged facing the probe, A minute force measuring method for measuring the displacement of the beam member due to the force acting between the probe and the sample. 5. The minute force measuring method according to claim 4, wherein the probe is two-dimensionally moved along the surface of the sample while controlling the displacement of the beam member to be constant.