JPH03278341A - Fine probe electrode employed recording/reproducing device - Google Patents

Abstract

PURPOSE:To record and reproduce a recording medium having a rugged surface by specifying a fine probe electrode in shape. CONSTITUTION:The fine probe electrode 3 possesses a probe shaft part whose cross-sectional area changing rate is continuously <=10% along the axial direction of the fine probe electrode 3 by >=5 nm, and a tip part is formed at an end part of the probe shaft part. In order not to allow the fine probe electrode 3 to contact or remarkably approach with its part other than the tip to the rugged recording medium, this can be realized by equalizing all the cross-sectional shapes in the vicinity of the tip of the fine probe electrode positioned within a height of a rugged part of the recording medium. By this method, even on such a recording medium having raggedness, the recording and reproducing of information can accurately be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording/reproducing apparatus that performs electrical recording/reproducing on a recording medium using probe electrodes.

[Conventional technology]

In recent years, the use of memory element f has become the core of the electronics industry, such as computers and related equipment, video disks, digital audio disks, etc.
Its development is also progressing very actively.

The performance required of memory devices varies depending on the application, but in general, they include: ■ High density and large storage capacity ■ Fast response speed for recording and playback ■ Low power consumption ■ High productivity and low price. .

Until now, semiconductor memory, magnetism, and memory were mainly made of magnetic materials and semiconductors, but in recent years, with the advancement of laser technology, inexpensive and high-density optical memory using organic thin films such as organic dyes and photopolymers has been developed. Recording media has appeared.

On the other hand, scanning tunneling microscopes (Scanning Tunnel Microscopes), which can directly observe the electronic structure of surface atoms of conductors, have recently been developed.
l Microscope: Hereinafter abbreviated as STM. )
was developed (G, B1nn1g et al., He
1vetica Physica Acta, 55.7
26 (1982)), it became possible to measure real space images with high resolution regardless of whether they were single crystal or amorphous, and it also had the advantage of being able to observe with low power without damaging the recording medium due to current. Furthermore, it is expected to have a wide range of applications because it can operate even in the atmosphere and can be used for various harmful substances.

STM utilizes the fact that when a voltage is applied between a metal probe (probe electrode) and a conductive substance and the probe is brought close to a distance of about 1r+a+, a tunnel current flows. This current is very sensitive to changes in the distance between the two, and by scanning the probe electrode while keeping the tunneling current constant, it is possible to draw the surface structure in real space, and at the same time to draw various information about the total electron cloud of surface atoms. Information can also be read. In this case, the recording/reproducing method is particle beam ('N, sagittal beam,
ion beams) or high-energy electromagnetic waves such as X-rays and energy rays such as visible and ultraviolet light to change the surface condition of the recording layer of a suitable recording medium to perform recording and playback with STM. As a method for recording and reproducing data using STM, a thin film layer of materials such as π-electron based organic compounds and chalcogenides, which have a memory effect on the switching characteristics of voltage and current, has been proposed. (
JP 63-161552, JP 63-16155
Publication No. 3, Publication No. 63-204531, etc.).

FIG. 8 shows an example of a probe electrode used in such a recording/reproducing method.

FIG. 8 shows a state in which a probe electrode 81 approaches a recording medium 82 having an uneven surface. In such a probe electrode 81, the smaller the radius of curvature of the tip, the better the resolution as a probe electrode. It is said to be expensive.

Conventionally, probe electrodes with tips with small curvature radii used for such purposes have been manufactured using cutting and electrolytic polishing methods. In the cutting method, it is possible to manufacture a probe electrode with a minute tip with a radius of curvature of 5 to 10 μm by cutting a fibrous crystal wire using a watch lathe. A thickness of 10 μm or less is also possible. In addition, the electrolytic polishing method involves straightening a wire rod with a diameter of 1 mm or less that will serve as the probe electrode, standing it vertically and immersing it in an electrolyte solution for about 1 to 2 mm, and applying a voltage to the probe electrode to stir the electrolyte solution as needed. While doing so, 0.5
The probe electrode is polished by intermittent energization at intervals of ~2.0 seconds. According to this method, the radius of curvature at the tip is 0
．． It is now possible to manufacture products as small as 0.05 μm.

Recently, a point surrounded by crystal facets has been used (Patent Application No. 63-226420),
Evaporation method (H, W, Fink,
IBM Journal of Research an
d Development 30.460 (+986
)), a probe electrode is used that has the theoretically smallest radius of curvature, with one to several atoms at the tip of the probe electrode (R, ^1lenspach).
and A, B15chof, ^ppHed Phys
icsLetters 54.587 (+989))
.

If such a probe electrode with a small radius of curvature is used, high-density recording and reproduction on the atomic order (several people) can be performed.

[Problem to be solved by the invention]

Among the probe electrodes manufactured by the conventional methods described above, if a probe electrode with an extremely small radius of curvature at the tip is used, it is possible to transfer information at extremely high density to a recording medium with a completely smooth surface. can be recorded accurately. However, in reality, it is difficult to obtain a smooth recording medium, and the surface of the recording medium often has large irregularities. In such a case,
When a conventional probe electrode is used, as shown by the arrow in FIG. 8, the surfaces of the probe electrode 81 and the recording medium 82 come into contact with or come very close to each other in areas other than the tip of the probe electrode 81, and the surface of the probe electrode 81 is connected to the recording medium 82. Information is recorded in the wrong position of 82. For this reason, when information is recorded using the probe electrode as described above, there are problems in that the recorded information cannot be reproduced or a recording density matching the radius of curvature of the tip of the probe electrode cannot be obtained. Therefore,
Until now, only a limited smooth area on the surface of the recording medium could be used, resulting in extremely poor yields. In addition, when using a recording medium with uneven grooves for tracking as shown in Figure 4, if you try to increase the recording density by narrowing the tracking width, it is difficult to accurately place the recording bits in the recesses that are less likely to be destroyed by friction. Due to the above-mentioned reasons, it is difficult to create a disk drive, and on the other hand, there is a problem in that information must be written on a convex portion that is easily destroyed by friction or the like.

The present invention has been made in view of the problems of the above-mentioned conventional techniques, and uses a microprobe electrode that enables accurate recording and reproduction of information even on recording media with uneven surfaces. The purpose is to provide recording/playback equipment.

[Means for Solving the Problems] A recording/reproducing device using a microprobe electrode of the present invention includes: a microprobe electrode; and a voltage is applied via the microprobe electrode to a recording medium having an electric memory effect. The apparatus includes a writing voltage applying means and a reading means for reading a change in the amount of current flowing through the recording medium, and the microprobe electrode is moved while the tip of the microprobe electrode and the recording medium are kept at a predetermined distance. In a recording/reproducing device using a microprobe electrode that scans on a recording medium to record and reproduce information on the recording medium, the microprobe electrode has a cross-sectional area change rate or an axis of the microprobe electrode. The micro probe electrode has a probe shaft portion that is continuous for 5 nm or more and within 10% along the direction, and the tip portion is formed at the end of the probe shaft portion, and the cross-sectional area change of the micro probe electrode The probe shaft has a cylindrical or prismatic shape, and the cross-sectional diameter or width of the probe shaft of the microprobe electrode is within 10% continuously for 5 nm or more along the axial direction of the microprobe electrode. 1 nm to 1 μm, the micro probe electrode is formed of a single crystal, the micro probe electrode is grown as a crystal on a support, the micro probe electrode is formed by providing a temperature gradient on the support. There is one in which the microprobe 'KPj is partially opened and the crystal is grown in the open part of a support coated with a resist layer.

[Function] The present invention maintains the distance between the tip of the microprobe electrode and the recording medium constant, thereby keeping the tunnel current generated between the microprobe electrode and the recording medium constant, and recording on the recording medium.・It performs playback.

In order to prevent this microprobe electrode from coming into contact with or significantly approaching a recording medium other than the tip, even with uneven recording media, as shown in FIG.
When recording or reproducing, this is achieved by making all the shapes of the cross sections near the tips of the micro probe electrodes located within the height of the uneven portion of the recording medium equal. However, even if all the cross sections of the microprobe electrode are not completely equal, if they are close to being equal, the possibility that the microprobe electrode and the surface of the recording medium will come into contact or come very close to each other at a point other than the tip of the microprobe electrode is reduced. Such a shape is a cylinder, a prism, or a shape close to these. In addition, the radius of curvature of the tip of the microprobe electrode does not exceed the radius of the cross section of the tip of the microprobe electrode or half the longest length, so if the area of the cross section of the microprobe electrode is reduced, The radius of curvature of the tip is also automatically reduced, making it possible to obtain sufficient resolution. Therefore, when recording or reproducing, the maximum cross-sectional diameter or width of the tip of the microprobe electrode located within the height of the uneven portion of the surface of the recording medium is determined by the recording medium used. Although it depends on the degree of surface unevenness, it is preferably 1r+m to 1 μm, and more preferably 1 nrn to 10 nrn.

When realizing a microprobe electrode with the shape described above,
There is one in which the microprobe electrode is formed on a support by crystal growth. In this case, later operations are easier if a very small number of crystals are grown only at desired locations on the surface of the support, rather than allowing them to grow unlimitedly on the surface of the support. In the present invention, in order to limit the region of crystal growth, microprobe electrodes formed mainly by the following two methods can also be used.

(2) A temperature gradient is provided on the support of the microprobe electrode, so that only a predetermined region is subject to crystal growth conditions.

(2) Cover the other surfaces with a suitable resist layer, leaving the area for crystal growth.

[Example] Next, an example of the present invention will be described with reference to the drawings.

[Embodiment 1] FIG. 1 is a block diagram showing an embodiment of a recording/reproducing apparatus using a microprobe electrode according to the present invention.

This recording/reproducing device applies a write voltage to both ends of the recording layer 7 of the recording medium 2, which is in a high resistance state (off state) in the initial state, to selectively change the low resistance portion (on state). Then, data is recorded, and during reproduction, data is reproduced by applying a voltage smaller than the switching threshold voltage and detecting a tunnel current from a probe 1, which will be described later.

In this recording/reproducing device, the recording medium 2 includes a substrate 5,
Consisting of a substrate electrode 6 and a recording layer 7, placed on a pedestal 8,
Fixed. The coarse movement mechanism 9 coarsely controls the vertical position of the recording medium 2 in order to maintain the distance between the recording medium 2 and the microprobe electrode 3 fixed to the support 4 of the probe 1 at a predetermined value. It is driven by the coarse movement drive circuit 10. An XY stage 11 is further provided below the coarse movement mechanism 9, and the position of the recording medium 2 can be moved in the XY force directions. The pulse power source 12 is for applying a pulse voltage for recording/erasing between the microprobe electrode 3 and the substrate chamber 8i6.

The probe current amplifier 13 amplifies the probe current of the minute probe electrode 3 and sends it to the servo circuit 14, and the servo circuit engineer 4 controls the fine movement control mechanism 15 so that the current from the probe current amplifier 13 reaches a desired value. Controls movement in the vertical direction. The fine movement control mechanism 15 is the XY scanning drive circuit 1
6 controls movement in the XY force directions. The above-mentioned circuits are collectively controlled by a microcomputer 17, and processing information of the microcomputer 17 is displayed on a display device 18.

Here, probe 1 used in the recording/reproducing apparatus of this embodiment
I will explain about it.

As shown in FIG. 2, the probe 1 generates whiskers, which are needle-shaped single crystals, on the support 4 to form microprobe electrodes 3.
The manufacturing method will be explained with reference to FIG. 3.

First, a support 4 having a protrusion 4a is prepared by electrolytically polishing a 1 mmφ tungsten wire, and the support 4 is inserted into the coil-shaped heater 20 with the protrusion 4a protruding. Further, Cu, which is a whisker-forming material 22, is placed in the tungsten filament 21 placed above the projection 4a of the support 4 so as to be in contact with the tungsten filament 21.

Then, the support 4 and the whisker-forming material 22 described above are placed in a high vacuum (about 10 −9 mmHg), and the support 4 is heated with the heater 20 .

At this time, the temperature of the support 4 near the heater 20 is approximately 80°C.
At 0°C, the temperature near the protrusion 4a, which is the tip of the support 4, is approximately 600°C.
℃, and there is a temperature difference within the support 4.

Next, the tungsten filament 21 placed on the top of the support 4 was heated to about 1000°C, and Cu, which is the whisker-forming material 22 placed in contact with the tungsten filament 21, was heated for about 10 minutes. A whisker 3 is formed near the tip of the protrusion 4a of the support 4 which has a low temperature.
has grown.

Whiskers were grown on several supports under the same conditions, and the support 4 on which only one whisker had grown upward, as shown in the microprobe electrode 8i3 in FIG. 3, was selected as the probe 1. This whisker was approximately 5 nm thick and 10 μm long. Moreover, the shape was cylindrical or prismatic.

In this embodiment, in order to make it possible to write information even in the concave portions of a recording medium having concavities and convexities, the micro probe electrode 8i3 is attached to a whisker (whisker), which is a needle-like single crystal, as described above.
sker), and this whisker has the following characteristics.

・Whiskers are extremely thin and thick needle-like crystals.

- If the crystal conditions are adjusted, the diameter can be made within 5 to 20 nm, so the radius of curvature of the tip of the microprobe electrode also falls within half of this range.

・Many metals and insulators, including metals commonly used for electrodes such as Au, Pt, and W, become whiskers.

・Since whiskers are single crystals with significantly smaller lattice defects than ordinary single crystals, they have extremely high mechanical strength despite their elongated shape.

・Measures that easily contaminate the surface of the probe electrode, such as polishing, are not particularly required.

In order to investigate the performance of the recording/reproducing device described above, the recording medium 2 has a striated structure of unevenness on the recording layer 7 as shown in FIG. was used.

(1) Width of recess = 10 nm, depth of recess = 10 nm, width of protrusion = 1OnI11 (2) Width of recess = 20 nm, depth of recess = 10 nm
, Width of convex portion = 10 nm (3) Width of concave portion = 50 nm, Depth of concave portion = 20
nm, width of convex portion = 20 nm (4) width of concave portion = 10OnII11, depth of concave portion = 30
r+m, width of convex portion=5Or+m For the above four types of recording media 2, the XY stage 11
The micro-probe electrode 3 of the probe 1 is moved along the recess by controlling the fine-movement control mechanism 15, while at the same time keeping the distance between the tip of the micro-probe electrode 3 and the recording layer 7 constant (r+m order) using the fine-movement control mechanism 15. A recording pulse voltage was applied to the recording layer 7 to perform recording, and it was then examined whether accurate reproduction could be performed.

As a result, the recording/reproducing device using the microprobe electrode 3 described above can accurately record in the recesses of all the four types of recording media 2 described above, and can accurately record information recorded in the recesses. I found out that it can be played.

Note that the microprobe electrode 3 used in Example 1 was misoperated during use and hit the sample surface, resulting in the tip of the whisker being chipped.
When applied to the support 4, whiskers were regenerated from the remaining portions of the whiskers, and the whiskers could be used again as microprobe electrodes.

By the way, the diameter of the grown whisker may not be as large as desired. However, if the diameter of the whisker is larger than the desired value, taking advantage of the fact that the whisker is a single crystal, the whisker can be melted faster or Under evaporation conditions, it can be reduced to the desired diameter.

Further, the shape of the tip of the whisker is not necessarily smooth, but in such a case, it is sufficient to take measures to make it smooth, such as by immersing only the tip in an electrolytic solution for a very short time or heating it to a high temperature.

As in this example, by forming the microprobe electrode with whiskers, which are needle-shaped single crystals, the microprobe electrode becomes extremely thin and has a thickness similar to that of the needle, so that the surface is uneven. Recording and reproduction can be performed accurately even on a certain recording medium, and the reliability of the recording/reproducing apparatus is improved. In addition, whiskers have high mechanical strength, so they have a long lifespan as microprobe electrodes, and
Even if the tip is accidentally cut off, regrowth is possible, which is economically advantageous. Furthermore, since the whiskers can be grown only in a predetermined region of the support, manufacturing of the microprobe electrode becomes easy.

[Example 2] Next, the second probe used in the recording/reproducing apparatus of the present invention will be described.
An example will be described with reference to FIG.

In the probe 51 of this embodiment, the support 54 is made of a single crystal of Ag, and the second part 52 has two crystal planes (1, 11).
It consists of four sides, two of which are (100).

The support 54 of this probe 51 was subjected to the same whisker growth operation as in Example 1 described above. However, this embodiment differs in that the evaporated whisker-forming material 22 is Ag and the heating temperature of the tungsten filament 21 is approximately 800°C. As a result of this operation, Ag whiskers having a <110> growth direction were epitaxially grown on the pointed end of the support 54 surrounded by two (111) planes and (100) planes. The grown whiskers had a thickness of about 10 nm and a length of 15 μm.

The probe 51 on which whiskers have grown as described above was incorporated as the probe 1 in the recording/reproducing apparatus shown in FIG. 1 in the same manner as in Example 1. Using the device created in this manner, recording was performed on four types of recording media with uneven portion shapes (1) to (4) in the same manner as in Example 1, and it was then examined whether accurate reproduction could be performed. .

As a result, when the probe 51 of this embodiment is used, recording media (2), (3), and (4) can be accurately recorded in the recesses of the recording media, and the information recorded in the recesses in parentheses can be recorded accurately. could be played accurately. However, regarding the recording medium (1), it was not possible to accurately record on the concave portions of the recording medium, and it was not possible to accurately record on the concave portions of the recording medium (1) using the probe 1 described in Example 1. The information could not be reproduced.

In addition, an attempt was made to regenerate whiskers in the same manner as in Example 1 with respect to the probe 51 produced in this example, and this was successful.

[Example 3] Next, the third example of the probe used in the recording/reproducing apparatus of the present invention will be described.
An example will be explained.

FIG. 6 shows the probe 61 of this embodiment.

The probe 61 of this embodiment is made of Si as shown in FIG.
A micro probe electrode 63 made of a whisker having an Au-Si alloy portion 65 at the tip is provided on a substrate 64.
The surfaces of the Si substrate 64 and the microprobe electrode 63 are made of Au.
- It is coated with a Pd layer 62 and has electrical conductivity.

In this example, in order to form a whisker as the above-mentioned micro probe voltage $463, v x= s ? j=(R
,5JAGNERand W,C,ELLIS: ^
PPLIED PHYSIGSLETTER54 (19
A whisker creation method called 86), 89) was used.

The principle of this VLS method is that Au-S is melted on a Si substrate.
When a droplet of i alloy is made and placed in an atmosphere of 5iC14, Si in the gas dissolves into the Au-Si droplet, resulting in a supersaturated state, and Si precipitates under the Au-Si droplet.
A whisker made of Si grows to lift the i-droplet.

A method for producing a probe using the VLS method will be described below with reference to FIG.

First, a Si single-crystal Si substrate 64 is prepared as a support, and a resist layer 66 is formed by applying a resist onto the (i ii ) plane thereof. Next, holes 67 with a diameter of about 1 μm are opened in the resist layer 66 at intervals of 5111 m using an electron beam.
A very small amount of Au was deposited on top of the resist layer 66, and the resist layer 66 was peeled off from the Si substrate 64. The amount of Au deposited was 0.2 nm according to the thickness meter of the crystal resonator, but the amount of Au deposited was 0.2 nm.
The film was not as thin as that, but in fact, it was Au particles 68 with an average diameter of 20 nm, and one to several of these particles were deposited in the eight holes 67 of the resist layer 66.

Next, this Si substrate 64 was cut into 5II 1m square pieces and subjected to a high-resolution scanning electron microscope (Scanning Elect
The diameter is 1 when viewed with a ronMicroscope (SEM).
A Si substrate 64 on which only one Au particle 68 of about 0r+m was evaporated was selected. Put the Si substrate 64 into a furnace,
After melting the Au particles 68 at a high temperature of 1000°C, the temperature was raised to about 400°C and a mixed gas of 5iC14 and H2 was introduced.
Whiskers with an average thickness of about 10 nm grew. Finally, the surface of the Si substrate 64 on which whiskers were generated was coated with Au--Pd to a thickness of 5r+m by sputtering to form an Au--Pd layer 62 to provide conductivity, thereby forming the probe 61.

In this example, in order to make the whiskers made of a non-conductive material conductive, Au-Pd was coated on the whiskers by sputtering, but other materials such as Au and PT can be used. The method is not limited to sputtering, but also includes plating, vapor deposition, etc.

An example of the probe 61 created as described above! Similarly, it is incorporated as a probe in the recording/reproducing apparatus shown in FIG.
Recording was performed on the four types of recording media (4), and then it was examined whether accurate reproduction could be performed.

As a result, the recording/reproducing apparatus using the probe 61 of this embodiment has the following characteristics for recording media (2), (3), and (4):
It was possible to accurately record information in the recessed portions of the recording medium, and to reproduce the information recorded in the recessed portions accurately. However, regarding the recording medium (1), it was not possible to accurately record information in the recesses of the recording medium, and information that was accurately recorded in the recesses of the recording medium (]) using the probe l described in Example 1 could not be recorded accurately. I couldn't even play it.

[Comparative Example] Next, in order to compare with each of Examples 1 and 2.3 described above, tungsten with a diameter of 1 mm was electrolytically polished in the conventional manner and shaped as shown in Fig. 8. It was incorporated as the probe 1 of the recording/reproducing apparatus shown in the figure, and recording was performed on the recording media (1) to (4) in the same manner as in Example 1, and then it was examined whether accurate reproduction could be performed.

As a result, in the recording/reproducing device using the probe 'rL pole made in the comparative example, it was possible to accurately record in the recessed part of the recording medium (4), and to accurately record the information recorded in the recessed part. It has been played. However, the recording medium (1
), (2), and (3), it was not possible to accurately record on the concave portions of the recording medium, and the recording medium (1), (2), and (3) could not be recorded using the apparatus of Example 1. It was also not possible to reproduce the information accurately recorded in the recesses.

Here, Table 1 shows the investigation results of the recording and reproducing operations according to the above-mentioned Examples 1.2.3 and Comparative Example.

Table 1 ○: Introducing combinations that could be recorded and reproduced accurately ×: Combinations that could not be recorded or reproduced accurately (1): Width of recess = 10
nm, depth of recess = 10 nm, width of protrusion = 10 nm (2): Width of recess = 20 nm, depth of recess = 10r++
n, Width of convex portion = 10 nm (3): Width of concave portion = 50 nn+, Depth of concave portion = 2
0 nm, width of convex portion = 20 nm (4): Width of concave portion =]00r+n+, depth of concave portion = 3
0 nm, width of convex portion = 50 nm [Effects of the Invention] As explained above, according to the present invention, since the tip portion is formed continuously to the probe shaft portion with a small cross-sectional area change rate, the tip portion of the microprobe electrode is In the vicinity of the tip, the shapes of the portions located within the height of the unevenness of the recording medium are approximately equal, and there is no possibility of contacting or coming very close to the recording medium at any location other than the tip. This makes it possible to accurately record and reproduce information even on a recording medium that has unevenness.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the recording/reproducing apparatus of the present invention, FIG. 2 is a sectional view of a probe incorporated in the recording/reproducing apparatus of the present invention, and FIG. 3 is a cross-sectional view of the probe shown in FIG. 2. FIG. 4 is a perspective view showing an example of the shape of a recording medium; FIG. 5 is a perspective view showing a second embodiment of a probe incorporated in the recording/re-dressing value of the present invention; FIG. 6 shows the third probe incorporated in the recording/reproducing apparatus of the present invention.
FIG. 7 is a cross-sectional view showing an embodiment, FIG. 7 is a view for explaining a method of manufacturing the probe shown in FIG. 6, and FIG. 8 is a cross-sectional view showing a conventional probe. Note that the arrows in FIGS. 2 and 8 indicate positions on the probe where current flows from the probe to the recording medium. 1.51.61--Probe, 2...Recording medium, 3.53.63--Minute probe electrode, 4.54...
-Support, 5...Substrate, 6-One-substrate electrode, 7...Recording layer, 8...Pedestal part, 9...Coarse movement mechanism,
10--Coarse movement mechanism drive circuit, 11-XY S-F-S,
12-pulse power supply, 13--probe current amplifier, 14--servo circuit, 15--fine movement control mechanism,
16...XY scan drive circuit, 17...Microcomputer-18...Display device, 20-...Heater 21.
...Tungsten filament, 22...Whisker forming material, 52-...Crystal plane, 62 =-A u -P d
layer, 64--Si substrate, 65--Au-Si alloy part, 66-- resist layer, 67-- hole, 68--Au particle.

Claims (7)

[Claims] (1) A microprobe electrode, a writing voltage applying means for applying a voltage to a recording medium having an electric memory effect via the microprobe electrode, and a reading means for reading a change in the amount of current flowing through the recording medium. , recording and reproducing information on the recording medium by scanning the microprobe electrode over the recording medium while maintaining a predetermined distance between the tip of the microprobe electrode and the recording medium;
In a recording/reproducing device using a microprobe electrode, the microprobe electrode has a cross-sectional area change rate of 5 nm or more continuously along the axial direction of the microprobe electrode.
0% or less, and the tip portion is formed at the end of the probe shaft,
Recording/reproducing device using micro probe electrodes. (2) The area change rate of the cross section of the microprobe electrode is 100 nm or more continuously along the axial direction of the microprobe electrode.
2. The recording/reproducing device using a microprobe electrode according to claim 1, wherein the probe shaft portion within % is cylindrical or prismatic. (3) A recording/reproducing device using a microprobe electrode according to claim 1 or 2, wherein the cross-sectional diameter or span of the probe shaft portion of the microprobe electrode is 1 nm to 1 μm. (4) A recording/reproducing device using a microprobe electrode according to claim 1, 2 or 3, wherein the microprobe electrode is formed of a single crystal. (5) A recording/reproducing device using a microprobe electrode according to claim 1, 2, 3 or 4, wherein the microprobe electrode is crystal-grown on a support. (6) A recording/reproducing device using a microprobe electrode according to claim 5, wherein the microprobe electrode is crystal-grown by providing a temperature gradient on the support. (7) The microprobe electrode according to claim 5, wherein the microprobe electrode is formed by growing crystals on the open portion of a support that is partially opened and covered with a resist layer. Recording/playback device used.