JPH05325274A - Piezoelectric displacement element, microprobe and their production as well as scanning type tunnel microscope and information processor constituted by using these members - Google Patents

Abstract

PURPOSE:To provide the cantilever-shaped displacement element and cantilever type probe which are used for the scanning type microscope and the information processor, warp-less, can be made pluralized and can be integrated. CONSTITUTION:Plural electrode and piezoelectric films 2, 3 and 2', 3' which are formed with the same batch and have the same crystallinity and stress state are stuck to each other by using an adhesive and are disposed symmetrically with a center line. As a result, the cantilever-shaped displacement element which does not generate the stress difference between the upper and lower layers and extremely little warps in the state of not impressing a voltage thereto is obtd. The scanning type microscope and information processor for which the cantilever type probe 4 constituted by providing the above-mentioned cantilever-shaped displacement element with a probe for information input and output is used are the devices having excellent reliability and stability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cantilever (cantilever) displacement element, a microprobe, used for a tunnel current detection device, a micro force detection device, a scanning tunnel microscope (hereinafter abbreviated as STM), and the like. The present invention relates to a cantilever type probe and a method for producing these.

Further, the present invention relates to an information processing apparatus for recording, reproducing, erasing information and the like by the method of STM provided with the above-mentioned microprobe and cantilever type probe, and STM.

[0003]

2. Description of the Related Art In recent years, an STM has been developed which can directly observe the electronic structure of surface atoms of a conductor, and enables real space images to be measured with extremely high resolution (nanometer or less) regardless of whether it is a single crystal or an amorphous structure. became. Further, at present, application to various fields such as atomic order and molecular order observation and evaluation of semiconductors or polymer materials, microfabrication, and recording / reproducing apparatus is being studied by using the STM method.

In particular, there is an increasing demand for a recording device having a large capacity for computer calculation information and the like, and due to the progress of semiconductor process technology, the microprocessor is downsized and the calculation capability is improved. Is desired. To meet these requirements,
Recording and writing are performed by changing the work function of the surface of the recording medium by applying a voltage from a converter consisting of a probe for generating a tunnel current existing on a driving means whose distance to the recording medium can be finely adjusted. A recording / reproducing apparatus has been proposed in which the minimum recording area is 10 nm square by reading information by detecting the change in the tunnel current due to the change.

In such an apparatus, it is necessary to scan a sample with a probe within a range of several nm to several μm, and a piezoelectric element is used as a moving mechanism at that time. As an example of this, three piezoelectric elements are combined so as to be orthogonal to each other along the x, y, and z directions, and a probe is arranged at the intersection of the three piezoelectric elements. There is a type such as a cylindrical type in which an electrode is divided, one end is fixed, a probe is attached to the other end, and a cylinder is deformed and scanned corresponding to each divided electrode.

More recently, against the background of semiconductor technology, mechanical electrical elements (micromechanics) such as semiconductor pressure sensors, semiconductor acceleration sensors, and microactuators using semiconductors as mechanical structures have come into the limelight. It was

Particularly, a micro-displacement element includes a cantilever-shaped element using a piezoelectric film, which is applied to the STM because it can control very fine movement. For example, an STM probe (I
EEE Micro Electro Mechani
cal Systems, p188-199, Feb.
1990). As shown in FIG. 18, a back surface of the Si wafer 181 is partially removed to form a silicon membrane, an Al thin film 183 and a ZnO thin film 184 are sequentially laminated on the front surface, a bimorph cantilever is formed, and then a reaction is performed from the back surface. The silicon membrane and the protective layer (silicon nitride film 182) for etching on the surface of the wafer are removed by dry etching to produce a bimorph cantilever for STM probe displacement.

A metal probe 185 is attached to the tip of the cantilever made of the above piezoelectric bimorph by adhesion or the like, and a tunnel current is detected through an extraction electrode (not shown). Since this cantilever has a bimorph structure, it has an excellent characteristic that a large amount of displacement can be obtained especially in the vertical direction.

Further, the probe driving mechanism formed by such a micromachining technique can be made fine and facilitates the pluralization of the probe required for improving the writing / reading speed of information of the recording / reproducing apparatus. It becomes possible. Further, this method can be said to be an excellent method because it can be directly incorporated into an IC process mainly using a Si semiconductor because the thin film technology of the piezoelectric material is used.

Further, in order to improve the observation resolution of the STM and achieve a high recording density of the information processing apparatus, it is required that the radius of curvature of the tip portion of the probe 185 is small.

Conventionally, in the method of manufacturing a probe, a tip obtained by mechanically cutting a material such as Pt and using it by accident is used as a probe, a material such as W is produced by electrolytic polishing, or a single crystal Si material is photo-processed. A method of making a pyramid-like shape by making full use of lithography technology and etching technology has been adopted.

Further, there is described a microprobe to which the oblique deposition and the lift-off method are applied by using the semiconductor manufacturing process technology (Japanese Patent Laid-Open No. 2-93349). Hereinafter, a method for manufacturing a microprobe according to this method will be described with reference to FIG. First, a mask layer 19 having a probe extraction electrode 192, a lift-off layer 193, and a circular or polygonal mask opening 195 on a support 191.
A composite thin film having a layered structure of 4 is prepared.

Next, as shown in FIG. 19A, a desired probe material 196 is applied obliquely toward the opening with respect to the composite thin film on the support 191 while the support 191 is rotated. Vapor deposition. At this time, the probe material 196 is also vapor-deposited on the mask layer 194, and the mask layer 19 is also formed.
Since the vapor deposition is also performed on the edge of the opening of No. 4, the mask opening 195 is covered as the vapor deposition progresses, and the area of the opening decreases (see FIG. 19B).

As a result, fine projections made of a vapor-deposited material having a sharp cone or a pyramid are formed under the mask layer 194. Then, the lift-off layer 193 is removed by a chemical treatment or the like to obtain the microprobe 197 on the support (see FIG. 19C).

[0015]

However, as shown in FIG.
In the cantilever shown in (1), the thickness and stress of each layer must be sufficiently controlled in order to stack many layers of electrodes and piezoelectric bodies. This is because the cantilever produced by etching away the Si substrate may warp depending on the film thickness and stress of each layer. In particular, the piezoelectric film is composed of nitrides and oxides, and the interface with the metal used as the electrode is a junction of completely different materials, and very large stress is generated there, especially when thinning it. , The stress generated at the interface is no longer a negligible value, unlike the case of a thick material such as bulk. Further, since the piezoelectric film is easily influenced by the base, even if the piezoelectric films are laminated with the same film thickness under the same conditions, the crystallinity of the ZnO thin films of the first and second layers is different. The stress of the piezoelectric body is different. Therefore, it is difficult to control the film thickness and stress of each layer so that the cantilever does not warp.

In addition, when a plurality of cantilevers are manufactured, the internal stress of the cantilevers varies due to the difference in the conditions during film formation, and as a result, the amount of warpage varies and the characteristics of each cantilever are not uniform. ..

Therefore, in order to improve the performance as the minute displacement element, it is necessary to reduce the warp due to the internal stress by some method.

Further, if an attempt is made to reduce the internal stress, the resistivity of the piezoelectric material will be lowered and the dielectric loss will be increased.

Further, the conventional probe manufacturing method has the following problems. (A) In the method using mechanical cutting, it is a method that relies on chance, and it is not possible to obtain a reproducible tip radius of curvature. (B) In the method using electropolishing, an oxide film layer may be formed on the surface and the tunnel current may not be detected by the STM. (C) Since the method shown in FIG. 19 is manufactured by the lift-off method using the composite thin film, the manufacturing process becomes long and the manufacturing cost becomes high.

The object of the present invention is to solve the above-mentioned problems. The cantilever-shaped displacement element made of the piezoelectric bimorph produced by the above-mentioned conventional method has excellent characteristics such as a large displacement amount and a small warpage, An object of the present invention is to provide a cantilever-shaped displacement element that can be integrated and integrated, and a manufacturing method thereof.

Further, an object of the present invention is to provide a microprobe having a sharp tip, and a method for producing a microprobe, which is easy to make into a multi-probe and which can simplify the process as compared with the prior art and which reduces the production cost. To provide.

Still another object of the present invention is to use the above cantilever-like displacement element to reduce the warpage during operation, and the reliability and stability of the cantilever probe or the minute probe. An object of the present invention is to provide an STM and an information processing device having excellent properties.

[0023]

Means and Actions for Solving the Problems The above object is achieved by the following constitutions.

That is, the first aspect of the present invention is, in a cantilever displacement element having a piezoelectric film and an electrode for displacing the piezoelectric film by an inverse piezoelectric effect, on the same substrate, under the same condition, more preferably, the same batch. A plurality of electrodes / piezoelectric films having the same crystallinity and stress state formed by, for example, a cantilever displacement element characterized by being arranged symmetrically about the center using an adhesive, Furthermore, it is a cantilever type probe in which an information input / output probe is provided on the free end side of the cantilever-shaped displacement element.

According to the first aspect of the present invention, by arranging a plurality of electrodes / piezoelectric films having the same crystallinity and stress state in a completely symmetrical form, a stress difference between upper and lower layers does not occur.
Therefore, it is possible to make the warp of the cantilever displacement element extremely small.

Next, the first aspect of the present invention will be described in detail with reference to the drawings.

1 to 4 show the procedure for producing the first piezoelectric displacement element of the present invention and a cantilever type probe using the same, and a schematic configuration diagram.

In the figure, 1, 1'is a substrate, 2, 2 ', 5,
5'is an electrode, 3'is a piezoelectric film, and 4 is a probe.

The first piezoelectric displacement element of the present invention is first shown in FIG.
As shown in (a), under the same conditions, preferably in the same batch, the electrodes 2, 2 ′ and the piezoelectric films 3, 3 ′ are deposited in this order on the same type of substrate 1, 1 ′, and then, as shown in FIG. As shown in b), they are arranged so that they are centrally symmetrical.

Next, as shown in FIG. 1C, the substrate 1 '
After removing, patterning is performed. Finally, as shown in FIG. 1D, the substrate 1 under the element is removed except for one end of the element.

The first piezoelectric displacement element of the present invention can also be manufactured by the method shown in FIG. First, as shown in FIG. 3A, electrodes 2, 2 ′, piezoelectric films 3, 3 ′, electrodes 5, 5 ′ are formed on the same type of substrate 1, 1 ′ under the same conditions, preferably in the same batch. After depositing in this order, as shown in FIG. 3 (b), they are arranged so as to be center-symmetric.

Next, as shown in FIG. 3C, the substrate 1 '
After removing, patterning is performed. Finally, as shown in FIG. 3D, the substrate 1 under the element is removed except for one end of the element.

Further, in the cantilever type probe using the above piezoelectric displacement element, as shown in FIGS. 1 (e) and 3 (e), a probe 4 for inputting / outputting information is provided at the free end portion of the piezoelectric displacement element. It is made by that. 2 and 4 are perspective views of this probe.

The operating principle of the first piezoelectric displacement element of the present invention will be briefly described below. In the piezoelectric displacement element manufactured by the method of FIG. 1, when an electric field is applied between the lower electrode 2 and the upper electrode 2 ′, the piezoelectric film 3 of the first layer and the piezoelectric film 3 ′ of the second layer are polarized. Since the directions of are different, one of the piezoelectric films 3, 3'is displaced toward the extension side for the same applied electric field,
The other causes a phenomenon of displacement toward the contraction side.

In the piezoelectric displacement element manufactured by the method shown in FIG. 3, the middle electrodes 5 and 5'are grounded, and a negative electric field is applied between the lower electrode 2 and the middle electrode 5 to form the middle electrode 5'and the upper electrode 2. '
When a negative electric field is applied between the first layer piezoelectric film 3,
Since the polarization directions of the piezoelectric film 3'of the second layer are different from each other, one of the piezoelectric films 3 and 3'is displaced toward the extension side and the other is displaced toward the contraction side with respect to the applied electric field. Phenomenon occurs. Therefore, the free end portion of the cantilever-shaped displacement element according to the first aspect of the present invention shown in FIGS. 1 and 3 is largely displaced upward or downward.

Materials used for the piezoelectric films 3 and 3'include AlN, ZnO, Ta ₂ O ₃ , PbTiO ₃ and Bi.
_There is no particular limitation as long as it is a material having piezoelectricity, such as ₄ Ti ₃ O ₁₂ , BaTiO ₃ , and LiNbO ₃ .

The method of forming the piezoelectric films 3 and 3'is not particularly limited, but the vapor deposition method, the sputtering method, the CVD method,
The sol-gel method or the like is used. Further, these film forming methods can be used in combination with assist such as plasma, active gas, and light irradiation.

The material used for the electrodes 2, 2 ', 5, 5'is preferably a noble metal, such as Au, Pt or Pd. When a material such as AlN or ZnO that can be formed at a relatively low substrate temperature is used for the piezoelectric films 3 and 3 ', a material such as Al can also be used for the electrodes. Furthermore, a conductive oxide such as ITO can also be used. Whichever material is used, the substrate 1,
In order to improve the adhesion between 1'and the electrodes 2, 2 ', a suitable adhesion layer (for example, Cr in a Cr / Au laminated film) can be used.

As a method of arranging a plurality of electrodes / piezoelectric films symmetrically about the center, brazing or the like can be applied, but from the viewpoint of simplicity, a method of bonding with an adhesive is preferable. Further, an epoxy adhesive or the like can be applied as this adhesive.

The patterning of the element portion is performed by combining photolithography using a normal photoresist, dry etching by reactive ion etching or the like, and wet etching using an etching solution such as acid or alkali. Further, if there is no suitable etching method for the electrodes and the like, a lift-off process can be used. The substrate 1 ′ above the element can be removed by chemical etching of the substrate, and the substrate 1 below the element can be removed by anisotropic etching of the substrate. In the case of Si normally used for the substrate, a typical method is to use Si ₃ N ₄ as a mask layer, pattern this mask layer, and then use an aqueous potassium hydroxide solution as an etching solution.

Next, the second aspect of the present invention will be described.

A second aspect of the present invention is a method for manufacturing a cantilever displacement element having a piezoelectric film and an electrode for displacing the piezoelectric film by an inverse piezoelectric effect, wherein the piezoelectric film is N
e A method of manufacturing a cantilever displacement element, which is characterized in that the displacement element is formed by a sputtering method in a mixed atmosphere.

According to the second aspect of the present invention, since Ne, which has a relatively small radius, is used in comparison with the conventionally used Ar, even if Ne atoms enter the lattice of the piezoelectric film, they have the effect of spreading them. Since it is smaller than that of Ar, the internal stress in the piezoelectric film can be reduced.

When Ne is present, the change in the value of internal stress is small with respect to the change in gas pressure during film formation.
When a plurality of cantilevers are manufactured, variations in internal stress value are reduced and variations in the amount of cantilever warp can be suppressed.

In the second aspect of the present invention, as the Ne mixed gas,
Is Ne / O ₂, Ne / N₂/ O₂Etc. can be applied, for example
Ne / O ₂When using, the mixing ratio is 0.1-9.
It is more preferably from 0 to 0.6 to 1.5.

As the material used for the piezoelectric film and the electrode, the same materials as those described in the first aspect of the present invention can be applied and are not particularly limited.

The patterning of the element portion is also the first aspect of the present invention.
Is the same as.

Next, the third aspect of the present invention will be described.

The third aspect of the present invention relates to a microprobe having a cutting edge radius of curvature sharpened to the order of atoms and molecules, and a manufacturing method thereof.

That is, a third aspect of the present invention is a microprobe having a sharp tip for detecting a tunnel current or a microforce, and the surface of the microprobe is made of a material such as a noble metal, a noble metal alloy, or a carbide. It is formed by being laminated and covered by a plurality of granular films having different diameters, and in the granular film, the particle diameter of the outermost granular film is preferably the smallest,
A microprobe characterized in that the particle diameter is in the range of 0.1 nm to 10 nm, and further, in a method for producing a microprobe having a sharp tip for detecting a tunnel current or a minute force, A method of manufacturing a microprobe, which comprises depositing a material to be a granular film from a gas phase to a solid phase, and laminating a plurality of granular films having different particle sizes, preferably, in the method of manufacturing the microprobe, A step of depositing sputtered particles of a material forming a granular film on the probe surface, and (a) a step of exchanging the material forming the granular film with a different material depending on the number of depositions. (B) heating temperature of the probe depending on the number of depositions. Step of lowering (c) Step of reducing the film thickness of the granular film according to the number of times of deposition A micro-program comprising at least one of the above steps (a) to (c) And a step of depositing cluster ions of a material forming a granular film on the surface of the probe, and (a) lowering the heating temperature of the probe according to the number of depositions and (b) the number of depositions. Step of reducing the acceleration voltage of the cluster ions accordingly (c) Step of reducing the film thickness of the granular film according to the number of times of deposition At least one of the above steps (a) to (c) It is a method of manufacturing a probe.

In the third aspect of the present invention, the material of the granular film is specifically Pt, Pd, Au, Au-P.
Materials such as d, Pt-Pd, Pt-Rh, TiC, WC and diamond can be used and are not particularly limited.

The method for forming the above-mentioned granular film may be a sputtering method, an ion beam sputtering method, a vapor deposition method, or the like, and is not particularly limited, but in controlling the radius of curvature at the tip of the probe, the sputtering method is used. Etc., the ion beam sputtering method is preferable.

Further, in the third method for producing a microprobe of the present invention, the heating temperature of the probe, the material to be the granular film, the accelerating voltage of cluster ions, the film thickness of the granular film, etc. are not particularly limited. The radius of curvature of the tip of the microprobe is appropriately changed so that the radius of curvature is appropriately changed.

Next, the third aspect of the present invention will be described with reference to the drawings.

FIG. 9 is an example of a cross-sectional view schematically showing the tip of a microprobe that best represents the third feature of the present invention, and FIG. 10 is an enlarged schematic view of the tip of the microprobe of FIG.

In FIG. 9, 91 is the outermost granular thin film, and 9
2 is a granular thin film of the first layer, and 93 is a probe for STM whose tip is sharpened by electrolytic polishing a material such as tungsten or platinum. FIG. 10A shows the probe 93 of FIG.
10 (b) is an enlarged schematic view of the tip of the probe 93, and FIG. 10 (c) is an enlarged schematic view of the tip of the probe 93 after the surface of the probe 93 is covered with the granular thin film 92 of the first layer. FIG. 9 is an enlarged schematic view of the tip after depositing the granular thin film 91 on the surface of the first granular thin film 92. The relationship between the sizes of the curvature radii R ₁ , R ₂ , and R ₃ at the leading edge of FIGS.
R ₁ > R ₂ > R ₃ .

As described above, by laminating a plurality of granular films having different particle diameters and successively decreasing the particle diameters, it becomes possible to reduce the radius of curvature of the tip of the microprobe.

Next, the fourth aspect of the present invention will be described.

According to the fourth aspect of the present invention, the microprotrusions formed on the electrodes are used as the basis of the shape of the microprobes, and the microprobes are formed by reflecting the shape of the microprotrusions by a directional film forming method. It is a thing.

That is, the fourth aspect of the present invention is, in a method of manufacturing a microprobe having a sharp tip for detecting a tunnel current or a microscopic force, the step of forming a patterned electrode on at least the surface of a support, On the electrode, for example
And a step of forming a fine projection with a photoresist, and a step of forming a probe material on the electrode including the fine projection by a directional film forming method such as a vacuum vapor deposition method or an ion beam sputtering method. It is a method for producing a characteristic microprobe, and further is a microprobe produced by the above-mentioned production method.

Next, the fourth aspect of the present invention will be described in detail with reference to the drawings.

FIG. 16 is a cross-sectional view showing an example of main steps of the fourth method for manufacturing a microprobe according to the present invention. FIG.
In (a), first, the support 161 is prepared. As the support 161, a material such as semiconductor, metal, glass, or ceramics can be used. Further, a substrate having a driving mechanism, such as a piezoelectric element or an electrostatic driving element, can be used.

Subsequently, the electrode 162 is formed on the support 161. Since the electrode 162 is a wiring for extracting a tunnel current, it may have high conductivity. For example, C
Examples include r, Al, Ti, Mo, Au, Pt and the like.
As a method of forming the electrode 162, a conventionally known technique, for example, a thin film forming technique such as a vacuum vapor deposition method, a sputtering method, a chemical vapor deposition method or the like, which is generally used in the semiconductor industry, a photolithography technique, and an etching technique are applied. However, the manufacturing method thereof is not a limitation of the present invention.

Next, as shown in FIG. 16B, the minute protrusion 163 is formed on the electrode 162. The micro-protrusion 163 according to the present invention is a basis for forming a micro-probe, and therefore it is desirable that the tip has a relatively sharp tip. Such a thing can be formed by a semiconductor manufacturing technique. For example, photolithography and etching, a method of overexposing and developing a photoresist, and the like can be mentioned.

Next, as shown in FIG. 1C, a probe material is formed on the entire surface by a directional film forming method. At this time, the support 161 can be tilted with respect to the vapor deposition source, that is, oblique vapor deposition can be performed to obtain a pointed shape. The directional film forming method includes a vacuum vapor deposition method and an ion beam sputtering method. Then, a minute probe can be manufactured by etching away the portion other than the probe region.

As described above, according to the fourth method of manufacturing a microprobe of the present invention, the microprotrusion is formed and then the probe is formed by oblique vapor deposition. Therefore, as compared with the conventional method shown in FIG. The manufacturing process can be simplified and the manufacturing cost can be reduced.

The fifth aspect of the present invention is a scanning tunneling microscope characterized by having the above-mentioned first, third, or fourth cantilever type probe or minute probe of the present invention.

A sixth aspect of the present invention is an information processing apparatus for recording / reproducing information on / from a recording medium by using a tunnel current or an atomic force, wherein the cantilever type of the first, third or fourth aspect of the present invention is used. An information processing apparatus having a probe or a minute probe.

[0069]

EXAMPLES The present invention will be described in detail below with reference to examples.

Example 1 This example relates to the first cantilever-shaped displacement element of the present invention.

First, as shown in FIG. 1A, electrodes 2 and 2'are formed on substrates 1 and 1'in the same batch. As the substrates 1 and 1 ', Si ₃ N ₄ was deposited on both surfaces of a Si single crystal substrate having a plane orientation (100) as a mask layer for anisotropic etching of the substrate to a thickness of 0.2 μm. The electrodes 2 and 2 ′ were Pt films, and were deposited to a thickness of 0.1 μm by ordinary high frequency sputtering.

Next, the piezoelectric films 3 and 3'were formed in the same batch. The film forming conditions are as follows: the target is ZnO, the substrate temperature is 200 ° C., the sputtering gas is a mixture of Ar and O ₂ at a ratio of 1: 1, the gas pressure is 0.5 Pa, and the plasma power during sputtering is 200 W. did.

Next, as shown in FIG. 1 (b), the two were bonded using an adhesive so that they were center-symmetric. Next, as shown in FIG. 1C, the substrate 1 ′ on the upper part of the device was removed by etching the substrate using a HF: HNO ₃ = 1: 5 solution. Next, after removing unnecessary portions of the piezoelectric thin films 3 and 3'and the electrodes 2 and 2'by ordinary photolithography, as shown in FIG. It was produced by removing the substrate 1 under the element except for one end portion of the element by reactive etching. The piezoelectric displacement element manufactured in this example has a length of 500 μm and a width of 50 μm.

When a voltage of ± 3 V was applied between the lower electrode 2 and the upper electrode 2'of the cantilever displacement element thus manufactured, the tip of the cantilever was displaced ± 5 μm in the vertical direction in FIG. ..

After forming the cantilever, the warp of the cantilever portion without applying a voltage is 0.5 μm at the tip portion.
It was below. Also, the fluctuation of the warp of the cantilever portion that occurs when the ambient temperature is changed without applying a voltage is very small, and the maximum is 0.1 μm within the range of 0 ° C.
It was m. Furthermore, neither cracks nor film peeling in the film used for the piezoelectric displacement element were observed at all, and no operation failure due to it was observed.

Next, as shown in FIG. 1 (e), a cantilever type probe using the piezoelectric displacement element manufactured in this manner is provided with a probe 4 for information input / output at the free end of the piezoelectric displacement element. It was prepared by providing. The probe 4 is Pt, R
It was formed by bonding metal pieces such as h and W.

Further, an STM device using the above cantilever type probe was manufactured. A block diagram of this device is shown in FIG.

In the present apparatus, first, the cantilever type probe produced in the present example of 51 in the figure is used to measure 52 samples and 4
After bringing the probe of No. 3 closer (Z direction in the figure), the X and Y directions in the plane of the sample 52 are scanned by the XY stage 53.
A voltage is applied between the probe 4 and the sample 52 by the bias voltage application circuit 54, and the tunnel current observed at this time is read by the tunnel current amplifier circuit 55 to perform image observation.

The drive control circuit 56 controls the distance between the sample 52 and the probe 4 and the drive control of the XY stage, and the CPU 57 controls the sequence of these circuits. Although not shown in the figure, as a scanning mechanism by the XY stage 53, a cylindrical piezo actuator,
This is done using a control mechanism such as a parallel spring, a differential micrometer, a voice coil, and an inch worm.

Using this apparatus, the surface of the sample 52 was observed using a HOPG (graphite) plate. A bias voltage application circuit 54 applies a DC voltage of 200 mV between the probe 4 and the sample 52, and in this state, the probe 4 is scanned along the sample 52 and the surface detected by the tunnel current detection circuit 55 is detected. Observed. Observation with a scan area of 0.05 μm × 0.05 μm revealed that a good atomic image could be obtained.

Next, an information processing apparatus using a plurality of cantilever type probes manufactured in this example was manufactured. The configuration and block diagram of the main part of this device are shown in FIG.

Explaining with reference to this figure, 62 cantilever type probes produced in the present example are arranged in the recording / reproducing head 61 in the figure (only one of them is shown in FIG. 6). is there). These multiple probes 63
Are arranged so as to uniformly face the medium. 64 is a recording medium for recording information, 65 is a base electrode for applying a voltage between the medium and the probe, and 66 is a recording medium holder. As a recording medium, for example, Cr is used as a base electrode 65 on a quartz glass substrate by a vacuum deposition method with 50 Å Cr.
It was deposited and further Au was vapor-deposited on it by the same method as 300Å, and SOAZ (squarylium-bis-6-) was formed on it by the Langmuir-Blodgett method.
A medium having an electric memory effect in which four layers of octyl azulene) are laminated is used. 67 is a data modulation circuit that modulates the data to be recorded into a signal suitable for recording, and 68 is the signal modulated by the data modulation circuit and the base electrode 65 and the probe 63.
A recording voltage applying device for recording on the recording medium 64 by applying a voltage between the two. When the probe 63 is brought close to the recording medium 64 up to a predetermined interval and a voltage exceeding a threshold value which causes a change in conductivity to the recording medium is applied by the recording voltage applying device 68, for example, a rectangular pulse voltage of 3 V and a width of 50 ns is applied, recording is performed. The characteristics of the medium 64 change and a portion having a low electric resistance is generated. Information is recorded by performing this operation while scanning the recording medium 64 with the probe 63 using the XY stage 69. Although not shown in the figure, as the scanning mechanism by the XY stage 69, a control mechanism such as a cylindrical piezo actuator, a parallel spring, a differential micrometer, a voice coil, an inch worm, etc. is used.

The recording voltage applying device 68 is also used for erasing recorded bits. That is, when the probe 63 is brought close to a recording bit on the recording medium 64 to a predetermined interval and a voltage exceeding a threshold value, for example, a triangular wave pulse voltage having a width of 7 V and a width of 50 ns is applied, the recording bit causes a characteristic change and the electric resistance is equal to It becomes the same value as the non-existing part, and the recorded bit is erased.

Reference numeral 70 denotes a recording signal detection circuit for applying a bias voltage between the probe 63 and the recording medium 64 to detect a tunnel current flowing between them, and 71 demodulates the tunnel current signal detected by the recording signal detection circuit 70. Data demodulation circuit. At the time of reproduction, the probe 63 and the recording medium 64 are arranged at a predetermined interval, and a voltage that does not exceed a threshold voltage that causes a change in conductivity of the recording medium, for example, a DC voltage of 200 mV is applied between the probe 63 and the recording medium 64. In this state, the tunnel current signal detected by the recording signal detection circuit 70 during scanning with the probe 63 along the recording data string on the recording medium 64 corresponds to the recording data signal. Therefore,
A reproduced data signal can be obtained by converting the detected tunnel current signal into a current voltage and demodulating it by the output data demodulation circuit 71.

Reference numeral 72 is a probe height detecting circuit. The probe height detection circuit 72 receives the detection signal of the recording signal detection circuit 70, cuts high-frequency vibration components due to the presence or absence of information bits, processes the remaining signal, and probes the remaining signal value to be constant. A command signal is transmitted to the x- and y-axis drive control circuit 74 in order to control the vertical movement of 63. This keeps the distance between the probe 63 and the medium 64 substantially constant.

Reference numeral 73 is a track detection circuit. When the probe 63 scans the recording medium 64, the track detection circuit 73 shifts the path along which the data of the probe 63 should be recorded, or the deviation from the recorded data string (hereinafter, these are referred to as tracks). This is the detection circuit.

As described above, the drive control circuit 74 cantilevers the drive control circuit 74 so that the probe travels while vibrating for tracking while adjusting the distance between the probe 63 and the medium by the signal of the data string obtained by the track detection circuit 73. Need to be displaced.

The above data modulating circuit 67, recording voltage applying device 68, recording signal detecting circuit 70, data demodulating circuit 7
1, probe height detection circuit 72, track detection circuit 7
3, z-axis drive control circuit 74, x, y-axis drive control circuit 74
Thus, the recording / reproducing circuit 75 is formed. The recording / reproducing circuit 75
Is controlled by the CPU 76 to become a recording / reproducing device.

It has been confirmed that the information processing apparatus of this embodiment can stably write, read, and erase recorded information with good reproducibility.

As the recording medium 64 for recording information,
Other than the above, any one having a memory switching phenomenon (electric memory effect) can be used.

The electric memory effect referred to in the present invention means at least two or more different resistance states corresponding to voltage application, and between each state, a voltage or current exceeding a threshold value that changes the conductivity of the recording layer is indicated. It can be freely transitioned by applying
It is also said that each of the obtained resistance states can be maintained as long as a voltage or current that does not exceed the threshold value is applied. Example 2 This example relates to the first cantilever-shaped displacement element of the present invention, and shows another mode of Example 1.

First, as shown in FIG. 1A, electrodes 2 and 2'are formed on substrates 1 and 1'in the same batch. As the substrates 1 and 1 ', Si ₃ N ₄ was deposited on both surfaces of a Si single crystal substrate having a plane orientation (100) as a mask layer for anisotropic etching of the substrate to a thickness of 0.2 μm. The electrodes 2 and 2 ′ were Au films, and were deposited by vacuum evaporation to a thickness of 0.1 μm.

Next, the piezoelectric films 3 and 3'were formed in the same batch. The film forming conditions are the same as in Example 1 except that the target is
nO, the substrate temperature is 200 ° C., the sputtering gas is a mixture of Ar and O ₂ at a ratio of 1: 1, the gas pressure is 0.5 Pa, and the plasma power during sputtering is 200
W.

Next, as shown in FIG. 1 (b), the two were bonded using an adhesive so that they were center-symmetric. Next, as shown in FIG. 1C, HF: HNO ₃ = 1: 5
The substrate 1 ′ above the element was removed by etching the substrate using the solution. Next, after removing unnecessary portions of the piezoelectric thin films 3 and 3'and the electrodes 2 and 2'by ordinary photolithography, as shown in FIG. It was produced by removing the substrate 1 under the element except for one end portion of the element by reactive etching.

The shape of the piezoelectric displacement element manufactured in this example is 500 μm in length and 50 μm in width.

When a voltage of ± 3 V was applied between the lower electrode 2 and the upper electrode 2'of the cantilever displacement element thus manufactured, the tip of the cantilever was displaced ± 5 μm in the vertical direction in FIG. ..

After forming the cantilever, the warp of the cantilever portion when no voltage is applied is 0.5 μm at the tip portion.
It was below. Also, the fluctuation of the warp of the cantilever portion that occurs when the ambient temperature is changed without applying a voltage is very small, and the maximum is 0.1 μm within the range of 0 ° C.
It was m. Furthermore, neither cracks nor film peeling in the film used for the piezoelectric displacement element were observed at all, and no operation failure due to it was observed.

Further, as in the first embodiment, a probe 4 for information input / output is provided at the free end of the piezoelectric displacement element produced as described above to form a cantilever type probe, which is used in FIG. When the STM and the information processing device shown in FIG. 6 were manufactured, good operation was performed as in the first embodiment.

Example 3 This example relates to the first cantilever-shaped displacement element of the present invention, and shows another mode of Examples 1 and 2.

First, as shown in FIG. 3A, electrodes 2 and 2'are formed on substrates 1 and 1'in the same batch. Board 1,
In 1 ', the screen of the Si single crystal substrate of the plane orientation (100),
Si as a mask layer for anisotropic etching of the substrate
₃ N ₄ 0.2 μm deposited was used. Electrode 2,
2'is a Pt film, which was deposited by ordinary high frequency sputtering to a thickness of 0.1 μm.

Next, the piezoelectric thin films 3 and 3'were formed in the same batch. The film forming conditions are the same as in Examples 1 and 2, the target is ZnO, the substrate temperature is 200 ° C., the sputtering gas is a mixture of Ar and O ₂ at a ratio of 1: 1 and the gas pressure is 0.5 Pa. Plasma power of 2
It was set to 00W.

Next, electrodes 5 and 5'were formed in the same batch. The electrodes 5 and 5 ′ were Pt films, and were deposited to a thickness of 0.1 μm by ordinary high frequency sputtering.

Next, as shown in FIG. 3 (b), the two were bonded by using an adhesive so that they were centered symmetrically. Next, as shown in FIG. 3C, the substrate 1 ′ on the upper part of the device was removed by etching the substrate using a HF: HNO ₃ = 1: 5 solution. Next, after removing unnecessary portions of the piezoelectric thin films 3, 3'and the electrodes 2, 2 ', 5, 5'by ordinary photolithography, an aqueous potassium hydroxide solution is used as shown in FIG. 3 (d). The substrate 1 below the element was removed by anisotropic etching of the element to remove one end of the element.

The shape of the piezoelectric displacement element produced in this example is 500 μm in length and 50 μm in width.

The middle electrodes 5 and 5'of the cantilever displacement element thus manufactured are grounded, and a voltage of ± 3 V is applied between the lower electrode 2 and the middle electrode 5, and the middle electrode 5'and the upper electrode 2 '. When ± 3 V was applied between the two, the tip of the cantilever was displaced ± 5 μm in the vertical direction in FIG.

After forming the cantilever, the warp of the cantilever portion in the state where no voltage is applied is 0.5 μm at the tip portion.
It was below. Also, the fluctuation of the warp of the cantilever portion that occurs when the ambient temperature is changed without applying a voltage is very small, and the maximum is 0.1 μm within the range of 0 ° C.
It was m. Furthermore, neither cracks nor film peeling in the film used for the piezoelectric displacement element were observed at all, and no operation failure due to it was observed.

As in the first and second embodiments, a probe 4 for inputting / outputting information is provided at the free end of the piezoelectric displacement element manufactured as described above to form a cantilever type probe. When the STM of No. 5 and the information processing apparatus of FIG. 6 were manufactured, good operation was performed as in Examples 1 and 2.

Example 4 This example relates to the first cantilever-shaped displacement element of the present invention, and shows another mode of Examples 1 to 3.

First, as shown in FIG. 3A, the electrodes 2 and 2'are formed on the substrates 1 and 1'in the same batch. Board 1,
In 1 ', the screen of the Si single crystal substrate of the plane orientation (100),
Si as a mask layer for anisotropic etching of the substrate
₃ N ₄ 0.2 μm deposited was used. Electrode 2,
2 ′ was an Au film, which was deposited by vacuum evaporation to a thickness of 0.1 μm.

Next, under the same batch conditions, the piezoelectric film 3,
3'was deposited. As in the case of Examples 1 to 3, the film forming conditions were as follows: the target was ZnO, the substrate temperature was 200 ° C., the sputtering gas was a mixture of Ar and O ₂ at a ratio of 1: 1 and the gas pressure was 0.5 Pa. The plasma power during sputtering was set to 200W.

Next, electrodes 5 and 5'were formed in the same batch. The electrodes 5 and 5 ′ are made of Au film and are formed by vacuum vapor deposition to a thickness of 0.
It was deposited to a thickness of 1 μm.

Next, as shown in FIG. 3 (b), the two were bonded using an adhesive so that they were center-symmetric. next,
As shown in FIG. 3C, the substrate 1 ′ on the upper part of the device was removed by etching the substrate using a HF: HNO ₃ = 1: 5 solution. Next, after removing unnecessary portions of the piezoelectric thin films 3, 3'and the electrodes 2, 2 ', 5, 5'by ordinary photolithography, an aqueous potassium hydroxide solution is used as shown in FIG. 3 (d). The substrate 1 below the element was removed by anisotropic etching of the element to remove one end of the element.

The shape of the piezoelectric displacement element produced in this example is 500 μm in length and 50 μm in width. The middle electrodes 5 and 5 ′ of the cantilever displacement element thus manufactured are grounded, and a voltage of ± 3 V is applied between the lower electrode 2 and the middle electrode 5, and between the middle electrode 5 ′ and the upper electrode 2 ′. When ± 3 V was applied, the tip of the cantilever was displaced ± 5 μm in the vertical direction in FIG.

After forming the cantilever, the warp of the cantilever portion without applying a voltage is 0.5 μm at the tip portion.
It was below. Also, the fluctuation of the warp of the cantilever portion that occurs when the ambient temperature is changed without applying a voltage is very small, and the maximum is 0.1 μm within the range of 0 ° C.
It was m. Furthermore, neither cracks nor film peeling in the film used for the piezoelectric displacement element were observed at all, and no operation failure due to it was observed.

Similarly to the first to third embodiments, the information displacement probe 4 is provided at the free end of the piezoelectric displacement element manufactured as described above to form a cantilever type probe. When the STM of No. 5 and the information processing apparatus of FIG. 6 were manufactured, good operation was performed as in Examples 1 to 3.

Example 5 This example relates to a second cantilever-shaped displacement element of the present invention.

In FIG. 7, when ZnO is used as the piezoelectric thin film and the film is formed by sputtering in a Ne / O ₂ atmosphere, the value of the lattice constant of ZnO in the c-axis direction is plotted against the gas pressure during film formation. It is a thing. As gas pressure decreases, Zn
Although the lattice constant of O in the c-axis direction increases, the lattice elongation is much smaller than that in the case of forming a film in the conventional Ar atmosphere shown in FIG.

This result means that the internal stress of the formed ZnO is small when Ne is used.

Further, in FIG. 7, since there is little change in the elongation of the lattice with respect to the change in pressure during film formation, it is possible to reduce the variation in the amount of warpage among a plurality of cantilevers.

A cantilever similar to that shown in FIG. 18 is replaced with Ne / O ₂
When ZnO was formed in a mixed atmosphere, the height difference between the tip of the free end of the cantilever and the Si substrate was ± 50% of the thickness of the cantilever in 200, which was the same as the conventional one. An improvement was obtained compared to ± 80% in the Ar / O ₂ mixed atmosphere.

FIG. 8 shows the resistance value of the ZnO film with respect to the internal stress. The resistance value of the ZnO film formed in the Ar mixed atmosphere decreases when the internal stress is near zero. This means that the dielectric loss becomes large, which leads to a large energy loss when driving the cantilever.

On the other hand, in the case of ZnO formed in the Ne / O ₂ mixed atmosphere, the resistivity tends to decrease in the vicinity of low stress, but its absolute value has a higher resistance than that of Ar. This means that a cantilever with low stress and low energy loss can be realized.

Example 6 This example relates to the third microprobe of the invention.

In this example, the third microprobe of the present invention as shown in FIG. 9 was prepared.

A method of manufacturing a microprobe will be described below with reference to FIG.
Will be explained.

FIG. 11 is a schematic view of a multi-source sputtering apparatus used for depositing a granular film. Reference numeral 93 is a tungsten probe, 110 is a heater for heating the probe 93, 111 is an axis rotating mechanism for rotating the probe 93, 112 is an angle adjusting mechanism for changing the angle of the probe 93, and 113 is one layer. Eye deposit material, 114 is power supply,
115 is a second layer deposition material, 116 is a power supply, 117 is a gas intake port, 118 is an exhaust port, and 119 is a vacuum container. The probe 93 was manufactured by forming a sharp tip using a 1 mm diameter tungsten rod with KOH as an etching solution and alternating current electrolytic polishing. The etching conditions were voltage: 2 Vp-p and current: 0.025A. The radius of curvature of the tip at this time was about 0.5 μm. The calculation of the radius of curvature of the tip was performed using a high resolution field emission scanning electron microscope. Au was used as the deposition material for 113. Pt—Pd was used as the deposition material for 115.

Next, the steps of stacking the deposited materials will be described.

First, the step of coating the surface of the probe 93 with the first layer deposition material 113 will be described. The deposited material 113 of the first layer is Au (the material is a 4-inch substrate). The probe 93 was rotated by the shaft rotation mechanism 111. Also, the angle adjusting mechanism 112 was adjusted so that the deposited material 113 of the first layer and the probe 93 were vertical. Argon gas was introduced into the vacuum container 119 through the gas inlet 117.

Next, the surface of the probe 93 was coated by the sputtering method under the following conditions.

Probe heating temperature: 150 ° C. Argon pressure: 2 mmTorr Power supply power: 200 W Deposition rate: 100 Å / min Sputtering was stopped when the film thickness reached 1000 Å.

Next, the step of depositing the second layer deposition material 115 on the surface of the first layer deposition material 113 will be described. Two
The deposition material 115 of the layer is Pt-Pd.

The probe 93 was rotated by the shaft rotating mechanism 111. Further, the angle adjusting mechanism 112 was adjusted so that the second-layer deposited material 115 and the probe 93 were vertical. Argon gas inlet 1 into the vacuum container 119
It was introduced from 17.

Next, the surface of the probe 93 was coated by the sputtering method under the following conditions.

Probe heating temperature: 80 ° C. Argon pressure: 2 mmTorr Power supply power: 200 W Deposition rate: 50 Å / min When the film thickness reached 300 Å, sputtering was stopped.

The tip of the microprobe thus manufactured was observed using a transmission electron microscope and a field emission electron microscope. As a result, the radius of curvature of the tip of the first layer is 0.1 μm.
And the radius of curvature of the tip of the second layer film was 5 nm.
As described above, a sharp microprobe with a very small radius of curvature of the tip could be manufactured.

Example 7 This example relates to the third microprobe of the present invention and shows another aspect of Example 6.

This embodiment will be described with reference to FIG.

FIG. 12 is a schematic view of a cluster ion beam apparatus used for depositing a granular film.

110 is a heater, 111 is a probe 93.
An axis rotation mechanism for rotating the material, 120 a deposition material, 121 a crucible, 122 an electron emission filament for heating the crucible 121, 123 an injection nozzle, 124 an electron extraction grid for ionization, 125 an accelerating electrode, 126 a cluster ion, 127 is a shutter for preventing the cluster ions 126 from irradiating the probe 93, and 128 is a vacuum container. Au was used as the deposition material 120.

The deposition method will be described below.

First, the probe 93 is rotated using the shaft rotating mechanism 111. Next, the Au material 120 contained in the crucible 121 is heated using the electron emission filament 122, evaporated from the injection nozzle 123, ionized by the electron extraction grid 124, accelerated by the acceleration electrode 125, and clustered as the cluster ion 126. The cluster ions are ejected toward 93. The first layer is deposited while the shutter 127 is opened. The deposition conditions for the first layer are shown below.

Probe heating temperature: 400 ° C. Ionization current: 300 mA Acceleration voltage: 8 kV Film formation rate: 2 Å / sec Based on the above conditions, 500 Å Au on the surface of the probe 93.
Deposited. The shutter 127 was closed immediately after the deposition.

Next, the second layer is deposited under the following conditions. After changing the conditions, the shutter 127 was opened.

Probe heating temperature: 80 ° C. Ionization current: 200 mA Acceleration voltage: 7 kV Film formation rate: 0.5 Å / sec Under the above conditions, 200 Å of Au was deposited on the first deposited film. The shutter 127 was closed immediately after the deposition.

Next, the third layer is deposited under the following conditions. After changing the conditions, the shutter 127 was opened.

Probe heating temperature: room temperature Ionization current: 150 mA Accelerating voltage: 7 kV Deposition rate: 0.5 Å / sec Based on the above conditions, 100 Å Au was deposited on the deposition surface of the second layer.
Deposited. The shutter 127 was closed immediately after the deposition. The tip of the microprobe thus produced was observed using a transmission electron microscope and a field emission electron microscope. As a result, the radius of curvature of the tip of the first layer film is 0.2 μm,
The tip radius of curvature of the second layer film was 50 nm, and the tip radius of curvature of the third layer film was 12 nm.

Embodiment 8 In this embodiment, the third microprobe element of the present invention is mounted on an STM device.

FIG. 13 is a block diagram of the STM device of this embodiment according to the present invention.

Reference numeral 130 in the figure is a microprobe in which Au and Pt are laminated and coated using the multi-source sputtering apparatus of FIG. 11, and the tip curvature radius is 5 nm. 132 is HOP
An observation sample in which liquid crystal (10CB) molecules are vapor-deposited on G (highly oriented graphite), 133 is a sample stage, 134 is a piezoelectric element for fine movement that scans the probe 130 in three dimensions, and 135 is a probe 130 that roughly approaches the observation sample 132. A coarse movement mechanism, 131 a bias power source, 136 a current-voltage converter,
137 is a logarithmic converter, 138 is a comparator, 139 is an integrator, 140 is a microcomputer, 141 is an amplifier,
Reference numeral 142 is a display device, and 143 is a fine movement cylindrical piezoelectric element 134.
Is a three-dimensional scanning circuit for three-dimensionally scanning the probe, and 144 is a coarse movement control circuit for bringing the probe 130 close to the electrodes.
When the probe 130 is attached to the fine-movement piezoelectric element 134, the probe 130 is set so that the angle of the tip of the probe 130 with respect to the scanning direction of the fine-movement piezoelectric element 134 is minimized.

Next, the surface observation apparatus of the present embodiment having the above-mentioned structure is operated in the atmosphere. In order to control the value of the tunnel current flowing between the probe 130 and the observation sample 132 to be a constant state of several nanometers, current-voltage conversion is performed with the bias power supply 131 set to a voltage of 100 millivolts. Unit 136, logarithmic converter 137,
An electrical feedback signal from the comparator 138, the integrator 139, and the amplifier 141 is applied to the fine-motion cylindrical piezoelectric element 134. The displacement amount of the cylindrical piezoelectric element 134 is 1 micrometer per kilovolt. Thereafter, the three-dimensional scanning circuit 143 moves the cylindrical piezoelectric element for fine movement 134 while applying electrical feedback to the probe 130 and the observation sample 13.
Scanning was performed so that the tunnel current flowing between the sample and the sample 2 was constant, and a molecular image of the sample surface was output to the display device 142.
The scanning speed of the probe 130 at this time was 2 milliseconds per line. In this output image, clear liquid crystal molecules were observed.

In the conventional W electropolishing probe, the pitch error of the observed molecule due to the distortion of the image at the scanning start portion is
Although often observed, the microprobe of the present invention did not observe the influence of image distortion or the like. An image with good resolution was also observed stably.

Example 9 In this example, the third microprobe element of the present invention is mounted on an information processing apparatus.

FIG. 14 is a block diagram of the information processing apparatus of this embodiment according to the present invention.

Reference numeral 130 in the figure denotes the third micro probe of the present invention in which three layers of Au are laminated by using the cluster ion beam device of FIG. 12, and the radius of curvature at the leading edge is 15 nm.

Reference numeral 149 is a probe current amplifier, and reference numeral 150 is a servo circuit for controlling the fine movement mechanism 151 using a piezoelectric element so that the probe current becomes constant. Reference numeral 152 is a power supply for applying a pulse voltage for recording / erasing between the probe electrode 130 and the substrate electrode 147.

Since the probe current changes abruptly when the pulse voltage is applied, the servo circuit 150 keeps the HO during that time.
The LD circuit is turned on so that the output voltage of the servo circuit 150 is controlled to be constant.

Reference numeral 153 is an XY scanning drive circuit for controlling the movement of the probe electrode 130 in the XY directions. 154 and 155 are for coarse movement control of the distance between the probe electrode 130 and the recording medium 145 so that a probe current of about 10 ⁻⁹ A can be obtained in advance. All of these devices are centrally controlled by the microcomputer 156. Reference numeral 157 represents a display device.

The mechanical performance of movement control using a piezoelectric element is shown below.

Z direction fine movement control range: 0.1 nm to 1 μm Z direction coarse movement control range: 10 nm to 10 mm XY direction scanning range: 0.1 nm to 1 μm Measurement and control tolerance: <0.1 nm The distance (Z) between the probe electrode 130 and the surface of the recording layer 146 is finely controlled by using a piezoelectric element so that the probe current flowing between the surface of the recording layer 146 and 130 is kept constant. Further, the fine movement control mechanism 151
Is designed to be capable of fine movement control in the in-plane (X, Y) directions while keeping the distance Z constant. However, these are all conventionally known techniques. In addition, the probe electrode 13
0 can be used for direct recording / reproducing / erasing. Further, the recording medium is placed on the high precision XY stage 158 and can be moved to an arbitrary position.

Next, recording / reproducing / erasing using an LB film (8 layers) of squarylium-bis-6-octylazulene (hereinafter abbreviated as SOAZ) formed on the substrate electrode 147 formed of Au. The details of the experiment are described below.

The recording medium 145 having the recording layer 146 in which the SOAZ8 layers were accumulated was placed on the XY stage 158, and first the position of the probe electrode 130 was visually determined and firmly fixed. A voltage of −1.0 V was applied to the probe electrode 130 with respect to the Au electrode 147, and the distance (Z) between the probe electrode 130 and the surface of the recording layer 146 was adjusted while monitoring the current. Then, when the distance between the probe electrode 130 and the surface of the recording layer 146 was changed by controlling the fine movement control mechanism 151, the current characteristic as shown in FIG. 15A was obtained.

The probe current and probe voltage
The probe electrode 130 and the recording layer 146
The distance Z to the surface can be adjusted, but the distance Z
In order to keep the value constant, the probe current I p
But,

[0163]

[Formula 1] Preferably,

[0164]

[Formula 2] It is necessary to adjust the probe voltage so that

First, the control current was set to the current value in the area a of FIG. 15A (10 ⁻⁷ A). Under this condition, the probe electrode 130 is in contact with the surface of the recording layer 146. The following experiment was conducted with the output voltage of the servo circuit 150 kept constant. When the current value was measured between the probe electrode 130 and the Au electrode 147 by applying a reading voltage of 0.5 V, which is a voltage that does not exceed the threshold voltage for producing the electric memory effect, and the current value was measured. .. Then O
After applying a triangular wave pulse voltage having a waveform shown in FIG. 15B, which is a voltage equal to or higher than the threshold voltage Vth ON for generating the N state, a voltage of 0.5 V is applied again between the electrodes and the current is measured. It was shown that a current of about 0.3 mA flowed and was in the ON state.

Next, when a triangular wave pulse voltage which is a voltage equal to or higher than the threshold voltage Vth OFF that changes from the ON state to the OFF state is applied and then 0.5 V is applied again, the current value at this time is μA or less and the state is OFF. Was confirmed to return to.

Next, the probe voltage is set to 0.5 V and the probe voltage is
Current I p is 10^-9A (corresponding to the area b in FIG. 15A)
It ), The probe electrode 130 and the recording layer 146.
The distance Z to the surface was controlled.

The XY stage 158 is moved at a constant interval (1 μm).
pulse voltage (Vmax = −15) equal to or higher than the threshold voltage Vth ON having the same waveform as described above while moving at m).
V) was applied to write the ON state. The output voltage of the servo circuit 150 is kept constant when the pulse voltage is applied.

For the written information, the distance between the probe electrode 130 and the surface of the recording layer 146 is controlled under the same conditions as the writing, and then the XY stage 158 is driven while keeping the output of the servo circuit 150 constant. Then, it is directly read by the change in the probe current between the ON state region and the OFF state region, or the servo circuit 150 is kept operating (H
OLD circuit OFF) XY stage 158 is driven and turned ON
It can be read by the change in the output voltage of the servo circuit 150 in the state region and the OFF state region. In this example,
It was confirmed that the probe current in the ON state region was changed by three digits or more as compared with that before recording (or the OFF state region).

Further, after controlling the distance between the probe electrode 130 and the surface of the recording layer 146 under the same conditions as in writing, the output of the servo circuit 150 is kept constant and the probe voltage is set to 8 V which is Vth OFF or higher. , The XY stage 158 is driven again to trace the recording position,
It was also confirmed that all the recorded states were erased and the state changed to the OFF state.

Instead of driving the XY stage 158, X
The Y drive circuit 153 is operated and the fine movement control mechanism 151 is driven to record at 0.01 μm intervals under the same conditions as described above.
Similar results were obtained even when the reproduction / erasure experiment was performed.
That is, after the distance from the surface of the recording layer 146 after writing is kept constant, the output of the servo circuit 150 is kept constant, and then the fine movement control circuit mechanism 151 is driven to trace the recording position. The change in probe current of 3 digits or more was confirmed by. Further, as a result of setting the probe voltage to 8 V under the same condition and tracing the recording position, it was confirmed that the recording state of 0.01 μm cycle was completely erased. A stable experiment was possible even if the above-mentioned recording / reproducing / erasing experiment was repeated.

Next, using the fine movement control mechanism 151, 0.0
Length 1μ with various pitches between 01μm and 0.1μm
When the m stripe was written by the above method and the resolution was measured, a change in probe current of 3 digits or more was always confirmed at the same pitch as the writing pitch at a pitch of 0.01 μm or more. When the pitch was less than 0.01 μm, the change in the probe current was gradually reduced, and when the pitch was 0.001 μm, it was difficult to observe the change in the probe current.

The SOAZ-LB film used in the above experiment was prepared as follows.

An optically polished glass substrate (substrate 148) was washed with a neutral detergent and trichlene, and then Cr was deposited as a subbing layer to a thickness of 50 Å by a vacuum evaporation method, and further Au was evaporated to 400 Å by the same method. An electrode (Au electrode 147) was formed.

Next, a chloroform solution in which SOAZ was dissolved at a concentration of 0.2 mg / ml was spread on the water phase at 20 ° C. to form a monomolecular film on the water surface. The surface pressure of the monomolecular film awaiting the evaporation of the solvent is increased to 20 mN / m, and while maintaining this constant, the speed is set so as to cross the water surface across the electrode substrate.
It was gently dipped at a rate of mm / min, and further pulled up to accumulate two layers of Y-shaped monomolecular film.

Example 10 This example relates to the fourth microprobe of the present invention.

This embodiment will be described with reference to FIG.
First, a silicon wafer on which a thermal oxide film of 5000 Å is formed is prepared as a support 161. Subsequently, gold is formed into a film having a thickness of 0.2 μm on the support 161 by a vacuum deposition method, and patterning is performed by photolithography and etching to form the electrode 1.
62 was formed. Note that Cr was used as a 50Å undercoat layer to improve the adhesion between gold and the thermal oxide film (Fig. 16 (a)).
reference).

Next, fine protrusions 163 were formed on the electrodes 162. The fine projections 163 are formed by using a positive photoresist A.
Z4620A (manufactured by Hoechst) was applied by a spinner, and prebaked at 90 ° C. for 30 minutes. The resist film thickness obtained at this time was 3.0 μm. Subsequently, after performing overexposure using a photomask having a pattern of a diameter of 3.0 μm, development is performed to obtain a height of 2.0 μm.
The conical micro-projections of were obtained (see FIG. 16 (b)).

Next, gold is formed as a probe material on the entire surface by an ion beam sputtering method, and a pattern is formed by photolithography and etching to form a probe 164.
Formed. The film thickness of gold at this time was 3.0 μm, and the film was formed by rotating the substrate at an angle of 15 ° from the facing position of the target.

Next, when the microprobe manufactured by the above-mentioned method was observed with an SEM (scanning electron microscope), a probe having a sharp tip was confirmed.
The radius of curvature of the tip of the probe was 0.09 μm.

Next, the microprobe manufactured in this example was mounted on an STM apparatus as shown in FIG. 13, and the surface of the observed sample 132 was observed using HOPG in the same manner as in Example 8. Similarly, a good atomic image could be obtained with good reproducibility.

Next, the microprobe manufactured in this example was mounted on an information processing apparatus as shown in FIG. 14, and an experiment for recording, reproducing and erasing information was carried out in the same manner as in Example 9. Good results were obtained as in Example 9.

Example 11 This example relates to the fourth microprobe of the present invention and shows another aspect of the tenth embodiment.

This embodiment will be described with reference to FIG.
First, a silicon wafer on which a thermal oxide film of 5000 Å is formed is prepared as a support 161. Subsequently, gold is formed into a film having a thickness of 0.2 μm on the support 161 by a vacuum deposition method, and patterning is performed by photolithography and etching to form the electrode 1.
62 was formed. Note that Cr was used as a 50Å undercoat layer to improve the adhesion between gold and the thermal oxide film (FIG. 17 (a)).
reference).

Next, SiO ₂ is added to the support 161 and the electrode 1.
A film having a thickness of 2 μm is formed on 62 by a sputtering method to form a protrusion forming layer
65 was formed. Then, a resist pattern 166 was formed on the protrusion forming layer 165 by photolithography. RD2000N (manufactured by Hitachi Chemical Co., Ltd.) was used as a photoresist to form a pattern having a diameter of 2 μm (FIG. 17).
(See (b)).

Next, the minute protrusions 163 were formed on the electrodes 162. The fine protrusions 163 were formed by etching the protrusion forming layer 165 to obtain conical fine protrusions having a height of 1.9 μm. At this time, a mixed solution of hydrofluoric acid and ammonium fluoride was used as the etching solution (see FIG. 17C).

Next, palladium was used as a probe material on the entire surface by an ion beam sputtering method, and a pattern was formed by photolithography and etching to form a probe 164. The film thickness of palladium at this time was 3.0 μm, and the substrate was tilted by 10 ° from the position facing the target and rotated to form a film (FIG. 17D).
reference).

Next, when the microprobe manufactured by the above-mentioned method was observed with an SEM (scanning electron microscope), it was confirmed that the probe had a sharp tip.
The radius of curvature of the tip of the probe was 0.07 μm.

Next, the microprobe manufactured in this example was mounted on an STM apparatus as shown in FIG. 13 and an information processing apparatus as shown in FIG. 14, and the same experiment as in Example 10 was conducted. Good results were obtained as in Example 10.

Example 12 This example relates to the fourth microprobe of the present invention, and shows another mode of Examples 10 and 11.

In this example, palladium was used as the probe material, and a probe was prepared in the same manner as in Example 11,
And, it was made in multi.

A vacuum deposition method was used for forming the palladium film. The number of probes was 100, arranged in a matrix. The pitch between the probes was 200 μm, and the opening diameter was 4 μm. SEM of the probe thus formed
The height of the probe was 5.3 μm ± 0.
The radius of curvature was 1 μm, and the radius of curvature of the tip was within the range of 0.06 μm ± 0.02 μm, and it was found that a probe having a uniform shape could be obtained in the case of multi-processing.

[0193]

As described above, the present invention has the following effects.

(1) In the piezoelectric displacement element according to the first aspect of the present invention, since the identically formed piezoelectric films can be arranged in a completely symmetrical form, a stress difference between upper and lower layers does not occur, and therefore, the conventional piezoelectric bimorph is used. The warp, which has been a problem with the cantilever-shaped displacement element, can be reduced to 0.5 μm or less at the tip portion, and the cantilever-shaped displacement element that can be integrated and made stable, and the cantilever-type probe using this can be stabilized. It is now possible to provide.

(2) According to the method for manufacturing a piezoelectric displacement element according to the second aspect of the present invention, the film is formed by sputtering in a Ne mixed atmosphere to reduce the internal stress in the piezoelectric film and reduce the warp amount of the cantilever. I can do things. Further, since the change in internal stress is small with respect to the change in pressure during film formation, it is possible to reduce variations in the amount of warp of the plurality of cantilevers, and it is possible to make the characteristics of each cantilever uniform.

Further, even if the stress is low, the decrease in the resistance value can be suppressed to the minimum, so that it becomes possible to provide the cantilever with low stress and less energy loss.

(3) According to the microprobe and the method for manufacturing the same according to the third aspect of the present invention, since the surface of the microprobe is coated with the granular thin films having different grain sizes, the microprobe having the tip radius of curvature on the order of atoms or molecules is formed. It became possible to provide the probe stably.

(4) According to the fourth embodiment of the present invention, the microprobe and the method for manufacturing the microprobe form the microprotrusion and then form the probe by oblique vapor deposition. Therefore, the process can be simplified as compared with the conventional method, and the manufacturing cost can be reduced. It is possible to provide a method for manufacturing a microprobe with reduced

(5) In the cantilever type probe, the scanning tunnel microscope and the information processing apparatus equipped with the minute probe according to the present invention, high resolution surface observation, reliability,
It became possible to record, reproduce, and erase information with excellent stability.

[Brief description of drawings]

1A and 1B are a manufacturing procedure and a schematic configuration diagram of a first piezoelectric displacement element and a cantilever type probe of the present invention.

FIG. 2 is a perspective view of the cantilever type probe shown in FIG.

3A and 3B are another manufacturing procedure and a schematic configuration diagram of the first piezoelectric displacement element of the present invention and the cantilever type probe.

FIG. 4 is a perspective view of the cantilever type probe of FIG.

FIG. 5 is a block diagram of an STM apparatus using the first cantilever type probe of the present invention.

FIG. 6 is a configuration and block diagram of a main part of an information processing device using a plurality of cantilever type probes according to the first aspect of the present invention.

FIG. 7 is a Z according to a second cantilever displacement element of the present invention.
It is the figure which plotted the relationship of the lattice constant and gas pressure of an nO film.

FIG. 8 is a Z according to a second cantilever displacement element of the present invention.
It is the figure which plotted the relationship between the resistance value of an nO film, and internal stress.

FIG. 9 is an example of a cross-sectional view schematically showing the tip of the third microprobe of the present invention.

FIG. 10 is an enlarged schematic view of the tip of the microprobe of FIG.

FIG. 11 is a schematic view of a multi-source sputtering device for explaining a third method for manufacturing a micro probe according to the present invention.

FIG. 12 is a schematic view of a cluster ion beam device for explaining a third method for manufacturing a micro probe of the present invention.

FIG. 13 is a block configuration diagram of an STM device using a third microprobe of the present invention.

FIG. 14 is a block configuration diagram of an information processing device using a third micro probe of the present invention.

15 is a graph of a distance between a probe electrode and a recording layer and a current characteristic and a triangular pulse voltage waveform in the information processing apparatus of FIG.

FIG. 16 is a cross-sectional view showing an example of main steps of a fourth method for manufacturing a micro probe of the present invention.

FIG. 17 is a cross-sectional view showing another example of the main steps of the fourth method for manufacturing a microprobe according to the present invention.

FIG. 18 is a diagram for explaining a method of manufacturing a conventional cantilever made of a piezoelectric bimorph.

FIG. 19 is a drawing for explaining the manufacturing method of the conventional microprobe.

[Explanation of symbols]

 1,1 'Substrate 2,2' Electrode 3,3 'Piezoelectric film 4 Probe 5,5' (middle) electrode 51 Cantilever type probe 52 Sample 53 XY stage 54 Bias voltage application circuit 55 Tunnel current detection circuit 56 Drive Control circuit 57 CPU 61 Recording / reproducing head 62 Cantilever type probe 63 Probe 64 Recording medium 65 Base electrode 66 Recording medium holder 67 Data modulation circuit 68 Recording voltage applying device 69 XY stage 70 Recording signal detection circuit 71 Data demodulation circuit 72 Probe height Detecting circuit 73 Track detecting circuit 74 X, Z-axis drive control circuit 75 Recording / reproducing circuit 76 CPU 91 Outermost surface granular thin film 92 First layer granular thin film 93 Probe 110 Heater 111 Axis rotating mechanism 112 Angle adjusting mechanism 113 First layer Deposition material 114 Power supply 11 Second layer deposition material 116 Power source 117 Gas intake port 118 Exhaust port 119 Vacuum container 120 Deposition material 121 Crucible 122 Electron emission filament 123 Injection nozzle 124 Ionization electron extraction grid 125 Acceleration electrode 126 Cluster ion 127 Shutter 128 Vacuum container 130 Micro probe ( Probe electrode) 131 Bias power supply 132 Observation sample 133 Sample stage 134 Fine movement piezoelectric element 135 Coarse movement mechanism 136 Current-voltage converter 137 Logarithmic converter 138 Comparator 139 Integrator 140 Microcomputer 141 Amplifier 142 Display device 143 3D scanning circuit 144 Coarse movement control circuit 145 Recording medium 146 Recording layer 147 Substrate electrode 148 Substrate 149 Probe current amplifier 150 Servo circuit 151 Fine movement control mechanism 152 Power source 153 XY scanning drive circuit 154 Coarse movement mechanism 155 Coarse movement drive circuit 156 Microcomputer 157 Display device 158 XY stage 161 Support body 162 Electrode 163 Micro protrusion 164 Probe 165 Protrusion forming layer 166 Resist pattern 181 Si wafer 182 Silicon nitride film 183 Al thin film 184 ZnO thin film 185 Probe 191 Support 192 Extraction electrode 193 Lift-off layer 194 Mask layer 195 Mask opening 196 Probe material 197 Micro probe

Front page continued (72) Inventor Keisuke Yamamoto 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshimitsu Kawase 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Toshihiko Miyazaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masahiro Tagawa 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Osamu Takamatsu 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yasuhiro Shimada 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yu Nakayama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (19)

[Claims] 1. A cantilever-shaped displacement element having a piezoelectric film and an electrode for displacing the piezoelectric film by an inverse piezoelectric effect, wherein a plurality of electrodes / piezoelectric films formed under the same conditions on the same underlayer, A cantilever-shaped displacement element characterized by being arranged symmetrically about a center. 2. The cantilever displacement element according to claim 1, wherein the plurality of electrodes / piezoelectric films are formed on the same base in the same batch. 3. The cantilever-shaped displacement element according to claim 1, wherein the plurality of electrodes / piezoelectric films are bonded to each other with an adhesive so as to be arranged symmetrically about the center. 4. A cantilever-type probe, wherein an information input / output probe is provided at a free end of the cantilever-shaped displacement element according to claim 1. 5. A method for manufacturing a cantilever displacement element having a piezoelectric film and an electrode for displacing the piezoelectric film by an inverse piezoelectric effect, wherein the piezoelectric film is formed by a sputtering method in a Ne mixed atmosphere. A method of manufacturing a cantilever-shaped displacement element, comprising: 6. A microprobe having a sharp tip for detecting a tunnel current or a microforce, wherein the microprobe surface is formed by laminating and coating a plurality of films. 7. The microprobe according to claim 6, wherein the plurality of films are granular films having different particle sizes. 8. The microprobe according to claim 7, wherein the granular film on the outermost surface of the granular film has the smallest particle size. 9. The particle diameter of the outermost granular film is 0.1 n.
The microprobe according to claim 8, which is in the range of m to 10 nm. 10. The material of the granular film is any one of a noble metal, a noble metal alloy, and a carbide.
The microprobe according to any one of 9 to 10. 11. A method of manufacturing a microprobe having a sharp tip for detecting a tunnel current or a microforce, comprising:
A method for manufacturing a microprobe, comprising depositing a material for forming a granular film from a gas phase to a solid phase on a probe surface, and laminating a plurality of granular films having different particle diameters. 12. The method for manufacturing a microprobe according to claim 11, wherein a step of depositing sputtered particles of a material to be a granular film on the probe surface, and (a) different materials to be a granular film depending on the number of depositions. Step of exchanging the material (b) Step of lowering the heating temperature of the probe according to the number of depositions (c) Step of reducing the film thickness of the granular film according to the number of depositions At least one of the steps (a) to (c) above A method for manufacturing a microprobe, which comprises two steps. 13. The method for manufacturing a microprobe according to claim 11, wherein the step of depositing cluster ions of a material forming a granular film on the surface of the probe, and (a) the step of lowering the heating temperature of the probe according to the number of depositions (B) Step of reducing the acceleration voltage of cluster ions according to the number of depositions (c) Step of reducing the film thickness of the granular film according to the number of depositions At least one of the steps (a) to (c) is included. A method of manufacturing a microprobe characterized by the following. 14. A method of manufacturing a microprobe having a sharp tip for detecting a tunnel current or a microforce,
At least a step of forming a patterned electrode on the surface of the support, and a step of forming fine protrusions on the electrode,
A method of manufacturing a microprobe, comprising the step of forming a film of a probe material on the electrode including the microprotrusion by a directional film formation method. 15. The method of manufacturing a microprobe according to claim 14, wherein the microprotrusion is formed of photoresist. 16. The method of manufacturing a microprobe according to claim 14, wherein the directional film forming method is one of a vacuum vapor deposition method and an ion beam sputtering method. 17. A microprobe manufactured by the method for manufacturing a microprobe according to any one of claims 14 to 16. 18. A method according to claim 4, claim 6 to claim 10, and claim 1.
7. A scanning tunneling microscope having the cantilever type probe or the minute probe according to any one of 7 above. 19. An information processing apparatus for recording / reproducing information on / from a recording medium by using a tunnel current or an atomic force, and the cantilever according to claim 4, claim 6 or claim 10. An information processing apparatus having a type probe or a minute probe.