JPH0862227A - Probe for scanning probe microscope, and microscope with the probe - Google Patents

Abstract

PURPOSE: To return a sample to an original measurement or processing position at atom level by eliminating or deforming partly or in whole a probe, and replacing a damaged probe by a new one without affecting a sample in measurement or process. CONSTITUTION: For example, when it is judged that a probe 19 is worn out or its tip is broken, the probe 19 having used at the most forward tip is broken at a breaking part 16 and is removed along with a support structure 14 so that a new probe 18 can be used, where the mechanical breaking force required for breaking the breaking parts 12, 15, and 16 is 12>15>16, probes 19, 18, 17, and 13 can be used in this order. A mechanical breaking device required for breaking the parts 12, 15, and 16 is operated by a manipulator whose one edge is fixed to the body part of a probe microscope. Since the mechanical breaking force is smaller at the breaking part 16 of the probe located at the tip, an object at the top edge can be eliminated simply by holding the support part 14 at the tip and twisting it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning tunneling microscope (STM). 57.1982 (G. Binn
ig, H. Rohrer, Phys. Rev. Lett., 49 , 57 (1982))),
Scanning Probe Microscop (SPM) such as AFM (Atomic Force Microscope)
e).

[0002]

2. Description of the Related Art The conventional STM probe structure has a structure in which the probe is directly attached to a piezoelectric ceramic for position detection, or a probe attached to a jig is attached to the piezoelectric ceramic (piezo). Was used. Also, AF
In the case of the optical lever method, the probe in M was attached at the same time when the cantilever was created. That is, the STM probe generally uses metal such as tungsten or platinum mechanically,
Alternatively, a sharpened tip is used by a method such as electric field polishing. The AFM has a silicon nitride cantilever and a silicon nitride probe, and the tip of the probe is sharpened by ion irradiation or the like. In the former case, usually, as shown in FIG. 2, the probe 2 made of tungsten is attached to the piezoelectric ceramic (piezo) 1 and the surface of the sample 3 is observed.

[0003]

According to the conventional technique as shown in FIG. 2, if the once attached probe is worn during measurement, the cantilever is integrated with the probe and, if necessary, the cantilever. Etc. were all exchanged. For this reason, if the probe was damaged during measurement, all measurements had to be restarted from the beginning. In addition, atomic level switching devices (Japanese Patent Application No. 3-340649: Wada et al., Journal of Applied Physics, 74
Volume 7321 (1993), Y. Wada, et al., J. App
l. Phys., 74 , 7321 (1993).) If the probe is damaged during the production, it will be necessary to recreate the atomic level device from the beginning, resulting in extremely low efficiency.
In extreme cases, there was a possibility that it could not be completed to the end.

[0004]

The present invention has been made to solve the above-mentioned problems of the prior art, and when replacing the probe of a scanning probe microscope, mechanical, physical, chemical, Alternatively, by removing or deforming part or all of the probe by electromagnetic means, it is possible to replace a damaged probe without affecting the sample being measured or processed, so it is possible to replace it at the atomic level. It is possible to measure or return to the processing position.

[0005]

The probe for a scanning probe microscope according to the present invention has a structure having a plurality of probes at known positions or at least one reproducible probe, and is used first. If the probe breaks, move the probe in use to a known location, or
(1) Mechanically removing or deforming part or all of the probe, (2) Electromagnetically deforming part or all of the probe, (3) Chemically modifying part or all of the probe. By removing or deforming, (4) physically removing or deforming a part or all of the probe, a separately prepared probe can be used, or the probe currently in use can be reused. This makes it possible to continue the measurement of the atomic level and the creation of the atomic level device again from substantially the same point.

[0006]

【Example】

Example 1 In this example, a case where a part or all of the probe is mechanically removed or deformed will be described.

FIG. 1A shows a plurality of probes 13, 17, 1.
8, 19, support structure 14 for each probe, fractured portion 1
A probe P having a structure including 2, 15, 16 and the probe support portion 11 is shown in a sectional view. The probe P is used as one probe in the state shown in the figure, but when it is judged that the probe 19 is worn out or the tip is broken, as shown in FIG. The probe 19 used in the above is broken at the break-through portion 16 and removed together with the support structure 14, and a new probe 18 is used.
To be able to use. Here, the breaking portions 12, 15,
The mechanical breaking force required to destroy 16 is 12>15> 16, and the probes 19, 18, 17, and 13 can be used in this order. The mechanical breaking device required to break the breaks 12, 15, and 16 is performed by a manipulator whose one end is fixed to the main body of the probe microscope, but the mechanical breaking force is as described above. Since it is smaller than the break-through portion 16 of the probe shown in Fig. 1, if the force of grasping and twisting the support portion 14 at the tip end is applied, it is possible to naturally remove the leading edge as shown in Fig. 1 (b). .

Mechanically removing part or all of the probe,
Alternatively, another modified example will be described. FIG.
(A) is a structure composed of the probes 24, 29, 30 and the support structure 28, the breaking portion 23, and the probe supporting substrate portion 21, and has a plurality of the probes 24, 29, 30 and the breaking portion 23,
The structure in which these are supported by the probe support substrate portion 21 is shown. Further, the probes 24, 29, 30 are connected to wirings 25, 26, 27, respectively, and each has a common wiring 22. The dimensions (longitudinal direction) of the probes 24, 29, 30 increase in the order of 30>29> 24 and are used in this order. Probe 30
When is damaged, the probe 29 can be used by disconnecting it from the connecting portion 23 as shown in FIG. The intervals between these probes 30, 29, 24 are known. For example, when the probe 30 becomes unusable while observing the surface using the probe 30, the probe 3 is not used.
When 0 is cut off and the distance between the probe 30 and the probe 29 is corrected, the surface observing section is moved directly below the probe 29.

Mechanically removing part or all of the probe,
Alternatively, an embodiment according to another modified method will be described. FIG. 4A shows the probes 43, 45, 46 and the support structure 4.
1, a plurality of probes 43, 45 and 46 and a probe support part 4 in the structure including the probe support part 44 and the probe substrate part 42.
4 has a structure 4 supported by a support structure 41. FIG. 4B shows xy in FIG. 4A.
It is a figure which shows a cross section. In this structure, when the probe 46 is used, the probe 4 is centered on the probe support portion 44.
6 by rotating it downward from a few degrees to about 90 degrees,
6, support structure 41, probe support portion 44, and probe substrate portion 4
It is placed in a direction inclined from a plane composed of 2 to several tens of degrees. When the probe 43 is damaged, it is rotated upward by several degrees to several tens of degrees and returned to the original position or higher than it, and then the probe 45 is attached to the probe support portion 44. It is used by rotating it downward from the center about several degrees to about 90 degrees.

By precisely controlling the rotation angle and correcting the distance between the probes, it is possible to continue measuring the atomic level by SPM and producing the atomic level device almost continuously again from substantially the same point. enable. Although the triple probe structure has been described in the present embodiment, it goes without saying that the number of probes can be increased as necessary. Further, it goes without saying that the structures of the support structure 41, the probe support portion 44, the probe substrate portion 42 and the like are merely examples, and the present invention is not limited to this structure. The essence of this embodiment is that a plurality of probes are prepared and these probes are used in sequence.

Example 2 An example will be described in which a part or all of the probes are chemically or physically removed or deformed to make a plurality of probes replaceable.

FIG. 5A shows a state in which the outermost layer 51 is used for the tip portion of the probe in the probe 50 having the multilayer structures 51, 52 and 53.

FIG. 5B shows irradiation with a reactive beam that chemically removes the outermost layer 51 or an ion beam 54 that physically removes the outermost layer 51 when the outermost layer 51 is damaged. However, the situation in which the outermost layer 51 is removed is shown. This removal amount depends on the damage state of the outermost layer 51, but may be removed entirely or only partially. For example, when the outermost layer 51 is made of silicon, it is possible to use an active chlorine chemical beam or an argon ion beam.

FIG. 5C shows atomic level measurement by SPM using the second layer 52, and when the second layer 52 is damaged during fabrication of an atomic level device, the second layer 52 is chemically removed. The reactive layer to be removed or the ion beam 54 to physically remove the second layer 52 is irradiated to the second layer 5
2 shows the situation where 2 is removed. For example, when the second layer is made of tungsten, it is possible to use an activated fluorine chemical beam or an argon ion beam.

Of course, in these chemical removal methods,
Chemically selective removal is possible, while in the case of physical removal, the selectivity is low.
The required structure can be realized by using the high-speed etching method.

In FIG. 5D, the second layer 52 made of, for example, tungsten is removed, and the third layer 53 made of, for example, gold.
Shows a state where the is exposed.

Although a three-layer structure has been described in this embodiment, it is needless to say that the number of layers can be increased as needed. Further, although the material forming the probe 50 is a combination of silicon, tungsten, and gold in this embodiment, any material that can be selectively removed from each other may be used, and the material is not limited to this. It is also possible to use a material that is not electrically conductive as the AFM probe, and a material that is generally used as the SPM probe can be used. By such a process, even if the probe is damaged, atomic level measurement by SPM from the substantially same point almost continuously again,
Allows you to continue creating atomic level devices.

Embodiment 3 In this embodiment, an example in which a part of the probe is chemically or physically removed or deformed to sharpen the tip of the probe again so that the same probe can be used is described. To do.

FIG. 6 shows a structure including a probe support substrate 61 and a probe 62. When the probe 62 is damaged at its tip, the reactivity to chemically sharpen the tip 64 of the probe is shown. A state in which a beam or an ion beam 63 for physically sharpening the tip 64 of the probe is irradiated to process the tip 64 of the probe into a usable shape again is shown. By such a process, even if the probe is damaged, it becomes possible to continue measuring the atomic level by the scanning probe microscope and making the atomic level device almost continuously again from substantially the same point.

Embodiment 4 In this embodiment, an example will be described in which a part of the damaged probe is chemically deformed to sharpen the tip of the probe again, so that the same probe can be used.

FIG. 7A shows a probe support substrate 71 and a probe 72.
When the tip of the probe 72 is damaged, the reactive gas 73 is made to flow while the tunnel current 74 is made to flow between the probe 72 and the sample 75. In this embodiment, when tungsten is used for the probe 72 and tungsten hexafluoride is flown as the reactive gas, the tunnel current 74 is passed between the sample 75 and the probe 72, as shown in FIG. 7B. New tip 76
Grows and can be used as a probe.

The growing position is a place separated by a predetermined distance from the place where the atomic level measurement and the production of the atomic level device are performed, and it is assumed that it does not affect the sample currently being measured or produced. I can.

By such a process, even if the probe is damaged, it is possible to continue measuring the atomic level by the scanning probe microscope and producing the atomic level device almost continuously again from substantially the same point.

Embodiment 5 In this embodiment, even if the tip of a probe in use is damaged by electromagnetically deforming or displacing a part or all of the probe, it is almost continuously and substantially the same point again. Will explain the probe structure that enables the atomic level measurement by the scanning probe microscope and the atomic level device fabrication to be continued.

FIG. 8A shows a probe assembly 85 including a substrate electrode 81, an insulating structure 82 between the electrodes, a probe supporting cantilever 83, and a probe 84. In such a probe assembly 85, when a voltage is applied between the substrate electrode 81 and the probe supporting cantilever 83, an attractive force is generated between the substrate electrode 81 and the probe supporting cantilever 83, and the probe 8
4 moves upward as shown in FIG. 8 (b).

In this embodiment, the substrate electrode 81 is a conductor made of silicon, and the probe supporting cantilever 83 is made of a polycrystalline silicon film sandwiched by silicon nitride films.
The probe 84 is made of tungsten. By applying a voltage of about 10 V between the substrate electrode 81 and the probe supporting cantilever 83, it was possible to sufficiently displace the probe 84 upward. FIG. 8C shows a state in which the probe assembly 85 having such a structure is arranged at a predetermined position to form a probe assembly group. The overall layout is shown in FIG. 8 (d).
It looks like the bird view shown in. Of course, like the embodiment shown in FIG. 3, the probes may be arranged in parallel so that they are arranged in parallel.

FIG. 9 shows a structure comprising a probe assembly 92 arranged on a substrate 91 and an alignment mark 93.
The alignment mark 93 is provided to detect the position of the probe assembly 92 on the substrate 91. For example, the alignment mark 93 is optically detected by a microscope, or electronically detected by an electron beam or the like, so that the substrate 91 can be detected. The position is precisely detected and the probe assembly can be aligned with the sample. The alignment mark 92 is provided on the sample (not shown) side,
It is also possible to detect the position by the probe of the probe assembly 93.

According to this method, since the position can be directly detected by the probe, the position accuracy can be improved, but on the other hand, the position detection capability is deteriorated. Therefore, it is most effective to use both in combination.

In the present embodiment, eight probe assemblies are arranged in a circle, and a voltage is applied so that the probe 84 is in a position as shown in FIG. The probe was sufficiently displaced upward, and measurement and operation were performed using one probe that was not displaced. It goes without saying that the arrangement of the probe assemblies does not have to be circular, but the mutual positions of the probes need to be known accurately.

When the probe in use is damaged, a voltage is applied to the support cantilever of the probe to change it from the used state to the unused state, and then applied to the probe support cantilever 83 of another probe. By turning off the applied voltage, the probe is put into use and the probe is replaced.

FIG. 10A shows an embodiment of a probe assembly group in which the probe assemblies 85 are arranged in parallel. As described above, in such a probe assembly 85, when a voltage is applied between the substrate electrode 81 and the probe supporting cantilever 83, the probe assembly 85 to be used can be selected from the probe assembly group. When the probe in use is damaged, a voltage is applied to the support cantilever of the probe to change it from the used state to the unused state, while the voltage applied to the probe support cantilever 83 of another probe is changed. When the probe is cut, the probe is used and the probe is replaced.

FIG. 10B shows an embodiment in which the probe assembly 85 is applied to an optical lever system. A cross-sectional view of the probe assembly 85 and a plan view corresponding thereto are shown. A hole 87 formed in the substrate electrode 81 irradiates the upper surface of the cantilever 83 with light such as a laser beam and the probe 84.
The displacement of can be measured. In the present embodiment, an example in which the vertical hole 87 is formed is shown, but the shape of the hole may be inclined or curved, and light can be emitted to the upper surface of the cantilever 83 and reflected light can be extracted. It should be.

[0033]

As shown in the above embodiments, according to the present invention, it is impossible to continue observation and preparation when the probe is damaged in the past, but it is possible to continue observation and preparation. It will be possible to observe and create at the atomic level with almost no limit.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment in which a part or all of a probe is mechanically removed or deformed.

FIG. 2 is a diagram showing an example of a probe structure of a conventional scanning tunneling microscope.

FIG. 3 is a diagram showing an embodiment in which part or all of the probe is mechanically removed or deformed.

FIG. 4 is a diagram showing an embodiment in which part or all of the probe is mechanically removed or deformed.

FIG. 5 is a diagram showing an embodiment in which part or all of the probe is physically or chemically removed or deformed.

FIG. 6 is a diagram showing an embodiment in which part or all of the probe is physically or chemically removed or deformed.

FIG. 7 is a diagram showing an embodiment in which a part of a probe is chemically deformed.

FIG. 8 is a diagram showing an embodiment in which part or all of the probe is electromagnetically deformed.

FIG. 9 is a diagram showing an example in which the position of a probe is adjusted.

FIG. 10 is a diagram showing an embodiment in which part or all of the probe is electromagnetically deformed.

[Explanation of symbols]

2, 13, 17, 18, 19, 24, 29, 30, 4,
3, 45, 46, 51, 52, 53, 62, 64, 7
2, 76; probe, 11, 21, 41, 61, 71, 9
1; support substrate, 12, 15, 16, 23; broken portion, 3,
75; sample, 22, 25, 26, 27; wiring, 85, 9
2; probe assembly, 93; alignment mark, 14, 2
8, 44; support structure.

Claims (6)

[Claims] 1. A scanning probe microscope, such as a scanning tunneling microscope or an atomic force microscope, wherein a plurality of probes are arranged in an exchangeable structure. 2. The scanning probe microscope according to claim 1, wherein the structure capable of exchanging a plurality of probes is formed by mechanically removing or deforming a part or all of the probes. Probe. 3. The probe for a scanning probe microscope according to claim 1, wherein the structure capable of exchanging a plurality of probes is one in which a part or all of the probes are electromagnetically deformed or displaced. needle. 4. The scanning probe microscope according to claim 1, wherein the structure capable of exchanging a plurality of probes is formed by chemically removing or deforming a part or all of the probes. Probe. 5. The scanning probe microscope according to claim 1, wherein the structure capable of exchanging a plurality of probes is formed by physically removing or deforming a part or all of the probes. Probe. 6. A scanning probe microscope comprising a plurality of probes arranged in a replaceable structure, and a manipulator for selectively removing one of the global probes.