JPH05215509A - Scanning-type probe microscope and manufacture of probe thereof - Google Patents

Abstract

PURPOSE:To expand a scanning range and to shorten a scanning time by scanning a plurality of probes of a scanning-type microscope. CONSTITUTION:In order to maintain a clean surface, a scanning-type tunnel microscope 13, which can be operated in an ultrahigh vacuum state, is used. For probes 11, W (tungsten), which has undergone electropolishing, is used. In order to attach a gold atom 14 on the tip of the probe, the probe is brought close to the surface of gold, and a positive voltage is applied on the probe 11. After the probe is arranged on the specified position of the surface of SiO2, a negative voltage is applied on the probe. The gold atom 14 is moved on the surface 12. By the same way, the gold atom 14 is manipulated again. The next gold atom 14 is manipulated on the surface 12 and arranged so that this atom is separated from the previous gold atom by 0.1mum. This procedure is repeated. Then, with the surface being maintained clean, W is selectively grown only at the part of the gold atoms by chemical vapor growth. Signal plugs are arranged on a plurality of the manufactured probes. The probes are brought close to an Si surface 16 in an ultrahigh vacuum state. When a tunnel current is detected, the approaching of multiple chips is stopped. A piezoelectric element 15 is operated, and the Si surface is finely moved and adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning probe microscope and a method of manufacturing a probe therefor. More specifically, it is possible to obtain information at high speed and in a wide range by scanning a plurality of probes. And a method for manufacturing the probe thereof.

[0002]

2. Description of the Related Art Conventionally, scanning tunneling microscopes and scanning force microscopes, which are typical scanning probe microscopes, use a piezo element to scan one probe and place it between the sample and the probe. Information such as the surface shape and electronic state of the sample was obtained by detecting the flowing tunnel current and interatomic force. For more details, “Basics and Applications of Surface Science” edited by the Society of Surface Science, Japan, August 1991, NTS, pages 222-234.
Page.

[0003]

In the prior art described above, for example, in the scanning tunneling microscope, when scanning a single probe such as tungsten or platinum iridium, the maximum scanning range is due to the non-linearity of the piezo element. It was a very narrow range of about 1 μm. Also, scan the probe,
There is a problem that it takes several seconds to several tens of seconds to form one image, and the actual image changes during that time. Further, when each atom on the solid surface is used as a recording medium, there is a problem that recording and reading take a very long time.

An object of the present invention is to reduce the scanning time of a scanning probe microscope. Another object of the present invention is to expand the maximum scanning range of the scanning probe microscope.

[0005]

The above object is achieved by simultaneously scanning a plurality of probes of a scanning probe microscope.

[0006]

In the conventional scanning probe microscope, 1μ
In order to obtain an image by scanning an area of m × 1 μm, it was necessary to divide it into, for example, 256 × 256 and measure all of this area with one probe. According to the present invention, if, for example, 10 × 10, that is, 100 probe needles are simultaneously scanned, an image of a region of 1 μm × 1 μm can be obtained.
An image will be obtained at the same speed as scanning a μm region.

Further, conventionally, due to the non-linearity of the piezo,
Only an image of an area of about 1 μm × 1 μm was obtained, but one probe was provided for each area of 1 μm × 1 μm, for example, 10 ×
By scanning 10 or 100 probes, it is possible to obtain an image of 10 μm × 10 μm, which is a 100 times larger area.

Furthermore, when recording and reading are performed by a scanning probe microscope using each atom on the solid surface as a recording medium, these can be performed at high speed.

[0009]

EXAMPLES The present invention will be described in detail below based on examples.

Example 1 First, a method of manufacturing a plurality of probes (multi-tips) capable of simultaneously scanning a plurality of scanning tunnel microscopes will be described.

First, as shown in FIG. 2, a conventional scanning tunneling microscope having a single probe is used to manipulate one to several tens of gold atoms to form a SiO ₂ (silicon dioxide) substrate. To 0.1
Two-dimensionally arrange 10 × 10 every μm. The specific operation of the gold atom is performed as follows. Scanning tunneling microscope capable of operating in ultra high vacuum to maintain a clean surface
13 was used. The probe used was electrolytically polished W (tungsten). To attach the gold atom 14 to the tip of the probe, bring the probe close to the gold surface, apply a positive voltage to the probe, and move the probe to Si.
After arranging at a predetermined position on the O ₂ surface 12, a negative voltage is applied to the probe this time, and gold atoms attached to the tip of the probe are transferred onto the SiO ₂ surface. In the same manner, the gold atom is manipulated again and placed on the surface of SiO ₂ at a distance of 0.1 μm from the previous gold atom. This process is repeated 100 times, and two-dimensional arrangement of 10 × 10 is made every 0.1 μm. Atoms to be arranged are valid other than gold atoms,
A semiconductor element such as Si, Ge, Sb, Ga or a metal atom such as Ag, Al or W may be used.

Next, while keeping the surface clean, W was selectively grown only on the gold atom portion by chemical vapor deposition. Specifically, WF ₆ (tungsten hexafluoride) and SiH
_A W crystal was grown at a forming temperature of 300 ° C. by a low pressure chemical vapor deposition method using ₄ (silane). The gas used is W
In addition to F ₆ and SiH ₄ , Ar and N ₂ were used as carrier gases. Regarding gas flow rate, WF ₆ and SiH ₄ are 80sccm
The carrier gas was 1100 sccm. Total pressure is 0.65 Torr
Met. It can be similarly formed by using SiH ₂ F ₂ (difluorinated silane) or H ₂ instead of SiH ₄ . As a result of forming the W crystal, as shown in FIG. 1, a probe group in which 100 W needle crystals were two-dimensionally arranged in 10 × 10, that is, a multi-chip was manufactured. The slight difference in the length of the probe can be achieved by aligning the tip by electrolytic polishing, processing by electron beam, or field evaporation by FIM or FEM.

A signal line was wired to the 100 manufactured probes, and the probe was used as a probe of a scanning tunneling microscope and operated. As shown in Fig. 3, the probe is made of Si (111) in ultra high vacuum.
Approaching the surface 16, the multi-chip approach was stopped when the tunnel current was detected. The Si surface was finely adjusted by operating the piezo element 15 so that the tunnel current was detected from each of the 100 probes. After the adjustment was completed, the images obtained from all the probes were combined and combined on the CRT so that each probe scans a region of 0.1 μm × 0.1 μm. As a result, an atomic image of the Si (111) surface in the area of 1 μm × 1 μm was obtained. With the same resolution, an atomic image was obtained 100 times faster in the case of multichip than in the case of using a single probe.

In this embodiment, 100 multi-chips have been described, but the present invention is not limited to this.

<Embodiment 2> A method for newly producing a multi-chip using the multi-chip 11 produced in Embodiment 1 will be described. The multi-tip 11 manufactured in Example 1 was attached to a scanning tunneling microscope 13 that can operate in an ultrahigh vacuum. The Si single crystal was previously processed into a needle shape so that it could be used as a probe of a scanning tunneling microscope, and as shown in FIG.
Make 1.

First, this Si single crystal was fixed on a sample stage of a scanning tunneling microscope. The multi-chip was brought close to the Si (111) surface, and the approach was stopped when the tunnel current was detected. The piezoelectric element 15 was operated to finely adjust the surface of Si so that the tunnel current was detected from each of the 100 tips.

After the adjustment was completed, the Si surface was electrically heated to a high temperature of 600 ° C. While maintaining this temperature, the probe was held under the conditions of 0.2 V and several nA. as a result,
Protrusion of Si atom 2 on the surface of Si (111) near the probe
1 was formed. That is, a 10 × 10 two-dimensionally arranged Si multi-chip could be manufactured.

Next, SiO ₂ was deposited on the portions other than the protrusions by the sputtering method. When the projections were sharp, almost no SiO ₂ was deposited on the projections. After that, by the chemical vapor deposition method, W is changed to S under the conditions described in Example 1.
The i atom was deposited on the surface of the protrusion. The chemical vapor deposition method was able to deposit on the protrusions.

Thus, 100 W multi-chips could be manufactured. As a result of examining the performance as a probe of a scanning tunneling microscope in the same manner as in FIG. 3 of Example 1, an atomic image of the Si (111) surface was similarly obtained at high speed. The invention of this embodiment enables multi-chip mass production. Even if one probe was brought a plurality of times (100 times in this embodiment) to approach, the same production was possible, but it required 100 times longer time.

<Embodiment 3> Another method for producing a new multichip using the multichip 11 produced in Embodiment 1 will be described.

The multi-tips produced in Examples 1 and 2 were attached to a scanning tunneling microscope capable of operating in an ultrahigh vacuum. A Si single crystal is processed in advance into a needle shape so that it can be used as a probe of a scanning tunneling microscope, and a multichip is newly formed on the tip portion (111) surface 22.

First, this Si single crystal was fixed on a sample stage of a scanning tunneling microscope. The multichip 11 was brought close to the surface of Si (111), and the approach was stopped when the tunnel current was detected. The piezoelectric element 15 was operated to finely adjust the surface of Si so that the tunnel current was detected from each of the 100 tips. After the adjustment was completed, the Si surface was electrically heated to a temperature of 200 ° C. While maintaining this temperature, the probe was held under the conditions of 0.2 V and several nA. Next, gold was deposited by electron beam on the Si (111) surface. Gold atoms move on the Si surface and gather at the tip of the probe, and the gold atom protrusions 2
1 was formed, and 100 multi-chips of gold arranged in a 10 × 10 two-dimensional array could be manufactured.

Although the electron beam evaporation method is used here,
Any method used for film forming techniques such as sputtering method, chemical vapor deposition method, molecular beam epitaxy method, vapor deposition method by resistance heating, and electron beam vapor deposition may be used. It is sufficient that the material can be supplied near the tip of the probe on the solid surface.

The multichip thus manufactured is
As a result of investigating the performance as a probe of the scanning tunneling microscope in the same manner as in FIG. 3 of Example 1, an atomic image of the Si (111) surface was similarly obtained at high speed. The invention of this embodiment enables multi-chip mass production.

<Embodiment 4> Another method of manufacturing a multi-chip will be described. First, on the Si substrate as shown in FIG.
A multi-layer film 23 in which W and Si were laminated 10 times at a cycle of 0.1 μm was produced. Since the period is the interval between the probes and the number of W layers is the number of the probes, these values can be changed appropriately. The method for producing the multilayer film may be any of a sputtering method, a chemical vapor deposition method, an electron beam vapor deposition method, a laser vapor deposition method and the like.

Next, the multilayer film is ground by a surface perpendicular to the film surface, and W
Was processed to be a thin line. Then, Si was etched to form only 10 thin W wires. Etching
Fluorine nitric acid, which was a mixture of 10 parts of nitric acid with 1 part of hydrofluoric acid was used. Further, W was electrolytically polished with a 2% NaOH (sodium hydroxide) aqueous solution to make the tip sharp and processed into a probe. The W tip can be processed by electron beam processing or field evaporation using FIM or FEM.

As a result, 10 W multi-chips 24 were produced as shown in FIG. As a result of examining the performance as a probe of a scanning tunneling microscope in the same manner as in FIG. 3 of Example 1, an atomic image of the Si (111) surface was similarly obtained at high speed.

<Embodiment 5> Wide area, for example, 10 μm × 10
A method for obtaining a μm region at the same speed as that for obtaining an image of a conventional 1 μm × 1 μm region will be described. A probe 32 such as W is attached to the tip of a Z piezo 31 that expands and contracts only in the direction of the probe, and this is processed to a thickness of 1 μm.

A structure in which 100 pieces are bundled is formed and used as a multi-chip as shown in FIG. One probe is 1 μm
It is provided in an area of × 1 μm, and an image of 100 times the area can be obtained by scanning 100 probes at the same time.

A signal line was wired to the 100 manufactured probes and used as a probe of a scanning tunneling microscope and operated. The probe was brought close to the Si (111) surface 16 in an ultrahigh vacuum, and the approach of the multichip was stopped when the tunnel current was detected. The Z piezo of the probe in which the tunnel current is detected is contracted, and the multichip is brought closer to the Si (111) surface. Next, when a tunnel current is detected from another probe, the Z piezo of that probe is contracted, and the multichip is brought closer to the Si surface.

By repeating this, the tunnel current is detected by all 100 probes. When the Si surface is inclined, the piezoelectric element 15 of the sample holder is operated to finely adjust the Si surface for adjustment. After the adjustment is completed, each probe scans the area of 1 μm × 1 μm,
Images from all tips were combined and synthesized on a CRT.

As a result, Si (111) in the area of 10 μm × 10 μm
An image of the surface was obtained. With the same resolution, an atomic image was obtained 100 times faster in the case of multichip than in the case of using a single probe. Further, when the operation is performed with one probe, the image may be distorted at the edge portion, but such a phenomenon did not occur.

<Embodiment 6> A method of recording and reading using a multi-chip will be described. As the recording medium, a clean sulfur atom surface (0001) of cleaved MoS ₂ (molybdenum disulfide) 34 is used. First, this was attached to a sample stage of a scanning tunneling microscope, and then 100 multichips 11 were brought close to the surface of sulfur atoms.

When the tunnel current was detected, the approach of the multichip was stopped. MoS ₂ was finely adjusted by operating the piezo element 15 so that the tunnel current could be detected from 100 probes. The multi-chip piezo element 13 may be operated and adjusted.

After the adjustment is completed, each probe is 0.1 μm ×
The images obtained from all the probes were combined so as to scan a region of 0.1 μm, and were combined on a CRT. As a result, an atomic image of the sulfur (0001) surface in the region of 1 μm × 1 μm was obtained. With the same resolution, an atomic image was obtained 100 times faster in the case of multichip than in the case of using a single probe.

Next, recording is performed. When scanning the multi-chip, when it comes to the atom at the position you want to record, bring the probe and the sulfur atom close to a distance of about 0.3 nm for 70 milliseconds, −
A 5.5V pulse 35 was input to the probe.

When pulses were applied to all the probes, several 100 probes were simultaneously recorded. Where Sulfur Atom Exists "
It was possible to freely record at high speed by forming a place "0" which was not set to 1 ". For reading, high-speed reading could be performed by scanning a multi-chip to confirm the existence of atoms.

Erasing is possible by redepositing sulfur atoms.

In this embodiment, 100 multi-chips have been described as an example, but the present invention is not limited to this.

Although the present invention has been described with reference to the embodiment of the scanning tunneling microscope, it can be sufficiently applied to a scanning probe microscope using another probe such as an atomic force microscope. For example, the probe of the atomic force microscope is manufactured by using the photolithography method, but a plurality of probes may be manufactured at the same time. The approaching and scanning methods of the probes are performed by measuring the force curve of each probe and detecting the atomic force of all the probes, as in the scanning tunneling microscope.

[0041]

According to the present invention, the scanning range can be expanded by simultaneously scanning a plurality of probes of the scanning probe microscope. Also, the larger the number of probes, the more effectively the time for forming an image is shortened.

[Brief description of drawings]

FIG. 1 is a diagram of a plurality of probes (multi-tips) capable of simultaneously scanning according to the present invention.

FIG. 2 is a diagram showing the operation of metal or semiconductor atomic groups by a scanning probe microscope.

FIG. 3 is a diagram showing a principle of scanning a solid surface with a multi-chip.

FIG. 4 is a diagram showing a method for newly producing a multi-chip with multi-chips.

FIG. 5 is a diagram showing a W / Si multilayer film.

FIG. 6 is a diagram showing a multi-chip formed from a W / Si multilayer film.

FIG. 7 is a diagram showing a multi-chip structure capable of scanning a wide area.

FIG. 8 is a diagram showing a principle of recording and reading using a multi-chip.

[Explanation of symbols]

11 ... Plural probes, 12 ... Probe support part, 13 ... Probe part with piezo element of scanning probe microscope, 14 ... Metal or semiconductor atom group, 15 ... Piezo element, 16 ... Si surface, 2
1 ... Newly formed plural probes, 22 ... Newly formed plural probe supporting portions, 23 ... W / Si multilayer film, 31 ... Z piezo, 32 ... Probe, 33 ... Signal line , 34 ... MoS ₂ , (molybdenum disulfide), 35 ... Pulse signal input to the probe.

Continued front page (72) Inventor Hisashi Nagano 2520 Akanuma, Hatoyama-cho, Hiki-gun, Saitama, Ltd.Inside of Hitachi Research Laboratories, Inc. In the laboratory

Claims (6)

[Claims] 1. A scanning probe microscope characterized in that a plurality of probes are formed on a solid surface, and these are simultaneously moved by one driving body. 2. A scanning probe microscope in which one or more metal atoms or semiconductor atoms are arranged at a plurality of positions on a solid surface, and a probe for a scanning probe microscope is grown at that position by crystal growth. Manufacturing method for medical probe. 3. A plurality of probes are made to approach each other on the surface of a solid, or one probe is made to approach a different position each time a plurality of times, and the probes are made to approach by heating the solid to a high temperature. A method for manufacturing a probe for a scanning probe microscope, wherein a plurality of probes are newly grown on the exposed portion. 4. A plurality of probes are brought close to each other on a solid surface, a probe material to be newly produced is arranged on the solid surface, and a plurality of new probes are grown from this material. Method for manufacturing a probe for a scanning probe microscope. 5. A scanning probe microscope, wherein a plurality of probes are arranged adjacent to each other so as to be independently movable, and means for independently driving each probe is provided. 6. A scanning probe microscope, wherein recording and reading are performed on a solid surface depending on the presence or absence of a predetermined atom arranged on the solid surface facing the plurality of probes.