JP4458263B2 - Probe, recording apparatus and reproducing apparatus. - Google Patents

Description

  The present invention relates to a probe that records and reproduces polarization information recorded on a dielectric such as a ferroelectric recording medium and scans the surface of the medium, and a technical field of a recording apparatus and a reproducing apparatus using the probe.

  The inventors of the present application have proposed a technique of a recording / reproducing apparatus using a scanning nonlinear dielectric microscope (SNDM) that analyzes a dielectric recording medium at a nanoscale. In SNDM, by using a conductive cantilever (probe) provided with a minute probe at the tip used for AFM (Atomic Force Microscopy) or the like, it is possible to increase the measurement resolution to sub-nanometers. . In recent years, development of an ultra-high density recording / reproducing apparatus that records data on a recording medium having a recording layer made of a ferroelectric material by applying SNDM technology has been underway (see Patent Document 1).

  In such a recording / reproducing apparatus using SNDM, information is reproduced by detecting the positive / negative direction of the polarization of the recording medium. This is because the oscillation frequency of the LC oscillator including the high-frequency feedback amplifier including the L component, the conductive probe attached thereto, and the capacitance Cs of the ferroelectric material immediately below the probe is a nonlinear dielectric caused by the positive / negative distribution of polarization. This is performed by utilizing the change caused by the change ΔC in the minute capacity resulting from the magnitude of the rate. That is, the change in the positive / negative distribution of the polarization is detected as a change Δf in the oscillation frequency.

  Furthermore, in order to detect the difference between the positive and negative polarities, by applying an alternating electric field having a frequency sufficiently lower than the oscillation frequency, the oscillation frequency changes with the alternating electric field, and the oscillation frequency including the sign is The rate of change is determined by the nonlinear dielectric constant of the ferroelectric material directly below the probe. Then, the component resulting from the alternating electric field is FM-demodulated and extracted from the high-frequency signal of the LC transmitter that is FM (Frequency Modulation) modulated in accordance with the change of the minute capacitance ΔC accompanying the application of the alternating electric field. The recorded information recorded on the ferroelectric recording medium is reproduced.

JP 2003-085969 A

  In such a probe, when recording information is recorded on or reproduced from the dielectric recording medium, the probe needs to be in a state where it is in contact with or substantially in contact with the dielectric recording medium. On the other hand, when the probe is moved to a desired position on the dielectric recording medium, it is necessary that the probe is not in contact with the dielectric recording medium so that the surface of the dielectric recording medium is not damaged by the probe. There is. That is, it is necessary to drive the probe vertically with respect to the dielectric recording medium. At this time, it is conceivable to form an actuator circuit including a piezoelectric element on the probe. However, the probe generally has a minute structure, and it has a technical problem that it is difficult to form such an actuator circuit on the probe in nanometer order. Furthermore, since an actuator circuit is formed, there is a risk of crosstalk with the wiring for supplying an electric field necessary for recording / reproducing operation of recorded information, which may lead to deterioration of recording / reproducing quality. Has technical problems.

  The present invention has been made in view of the above-described problems, for example, and provides, for example, a probe capable of driving a probe in a vertical direction with respect to the surface of a medium, for example, and a recording apparatus and a reproducing apparatus using the probe The task is to do.

In order to solve the above-described problem, the probe according to claim 1 is a probe that scans the surface of a medium, and includes a head portion including a protrusion whose tip faces the medium, and at least a part of the head portion. A first electrode to be formed; and a second electrode for applying an electric field between the first electrode and the first electrode, when viewed from the normal direction of the surface, The head portion is arranged in another area except for the arranged one area, and the head portion has a height of the first electrode and a height of the second electrode with respect to the surface when the electric field is applied. It is possible to bend so that the difference is reduced.

  The operation and other advantages of the present invention will become apparent from the embodiments described below.

(Probe embodiment)
An embodiment according to the probe of the present invention is a probe that scans the surface of a medium, and includes a head part including a protrusion whose tip faces the medium, and a first electrode formed on at least a part of the head part. And a second electrode for applying an electric field between the first electrode and the first electrode.

  According to the embodiment of the probe of the present invention, when the electric field applied from the protrusion returns to the return electrode, for example, a change in dielectric constant on the recording surface of the dielectric recording medium can be detected as a change in capacitance. it can. That is, the information recorded on the dielectric recording medium can be suitably reproduced. Further, for example, information can be suitably recorded on the dielectric recording medium by applying an electric field to the dielectric recording medium from the protrusions.

  In particular, the probe according to the present embodiment further includes a first electrode formed on the head portion and a second electrode to which an electric field is applied between the first electrode. By applying an electric field between the first electrode and the second electrode, an electrostatic force is generated between the first electrode and the second electrode. That is, an attractive force is applied between the first electrode and the second electrode. At this time, since the first electrode is formed on the head portion, an attractive force is applied to the head portion by applying an attractive force to the first electrode. Accordingly, the head portion can be driven (that is, moved or curved).

  In particular, by considering the positions at which the first electrode and the second electrode are formed as will be described later, it is possible to drive the head portion, for example, in a direction substantially normal to the surface of the medium. In other words, for example, if the head portion is on the upper side of the medium, the head portion (particularly, the protrusion) can be driven in a generally vertical direction with respect to the surface of the medium. By driving the head portion in this way, it is possible to realize a state where the protrusion is in contact with the medium or a state where the protrusion is separated from the medium. That is, it is possible to drive the head unit to a suitable state as necessary.

  Since it is sufficient to form the first electrode and the second electrode in order to drive the head portion, the circuit configuration is relatively simple. For example, the head unit can be suitably driven without forming a relatively complicated drive circuit using a piezoelectric element or the like on the head unit.

  Furthermore, since a relatively simple circuit configuration is sufficient, the occurrence of crosstalk (floating capacitance) with other wirings can be reduced or suppressed. For this reason, it is possible to stabilize the recording operation and the reproducing operation.

  As a result, according to the embodiment of the probe of the present invention, the protrusion can be driven so as to come into contact with or away from the surface of the medium (that is, in the vertical direction with respect to the medium). In addition, the circuit configuration necessary for driving the probe can be made relatively easy.

  In one aspect of the embodiment of the probe of the present invention, the second electrode is formed on a side opposite to the side facing the medium with respect to a position where the first electrode is formed. The

  According to this aspect, for example, when the medium is below the first electrode (projection), the second electrode is formed on the first electrode. For this reason, it becomes possible to drive the head part in a generally vertical direction with respect to the surface of the medium.

  In another aspect of the embodiment of the probe of the present invention, at least a part of the head portion is curved in advance toward the side facing the medium.

  In another aspect of the embodiment of the probe according to the present invention, the head portion may be disposed on the surface such that a portion where the protrusion is formed is closer to the medium than a portion where the protrusion is not formed. And having a predetermined angle.

  According to these aspects, it is possible to suitably drive the head portion substantially vertically with respect to the surface of the medium. In particular, even when the first electrode and the second electrode are not formed so as to be in a positional relationship along the normal of the surface of the medium (or the first electrode and the second electrode are on the surface of the medium). The head portion being curved in advance or being tilted with respect to the surface of the medium. Can be suitably driven substantially in the vertical direction with respect to the surface of the medium.

  In another aspect of the embodiment of the probe of the present invention, the second electrode does not contact the first electrode.

  According to this aspect, it is possible to cause a disadvantage that the first electrode and the second electrode come into contact with each other when the head unit is driven. Therefore, it is possible to prevent the head portion from being destroyed due to a large current flow or the occurrence of a pull-in phenomenon or the like.

  In another aspect of the embodiment of the probe of the present invention, when the electric field is not applied, the height of the first electrode with respect to the surface is different from the height of the second electrode.

  According to this aspect, at least when the electric field is not applied, the positional relationship between the first electrode and the second electrode is not substantially parallel to the surface. Accordingly, when an electric field is applied, a direction other than a direction parallel to the surface of the medium (that is, a direction intersecting with a predetermined angle with respect to the surface of the medium) between the first electrode and the second electrode. Static electricity is generated. Therefore, the head unit can be appropriately moved in the vertical direction with respect to the surface of the medium.

  When an electric field is applied, the first electrode and the second electrode may be in a positional relationship that is substantially parallel to the surface of the medium.

  In another aspect of the embodiment of the probe of the present invention, an electrostatic force is generated between the first electrode and the second electrode in a direction excluding a direction parallel to the surface by applying the electric field. The probe according to claim 1, wherein the second electrode is formed on the probe.

  According to this aspect, there is static electricity between the first electrode and the second electrode in a direction other than a direction parallel to the surface of the medium (that is, a direction intersecting with a predetermined angle with respect to the surface of the medium). Force is generated. Therefore, the head unit can be appropriately moved in the vertical direction with respect to the surface of the medium.

  Another aspect of the embodiment of the probe of the present invention includes a top plate for supporting the head unit, and the second electrode is formed on the top plate.

  According to this aspect, the top plate on which the second electrode is formed and the head portion on which the first electrode is formed can be manufactured in separate steps. That is, for example, even if there is a manufacturing mistake in the process of forming the second electrode, the top plate on which the second electrode is formed may be discarded, and the head part manufactured in another process may be discarded. It ’s enough. On the other hand, in a probe in which a drive circuit using a piezoelectric element or the like is integrally formed on the head portion, if there is a manufacturing error in one process, the entire probe needs to be discarded. For this reason, according to this aspect, the yield of the entire probe can be improved.

In the aspect of the probe including the top plate as described above, the distance between the joint portion of the top plate and the head portion and the first electrode is larger than the distance between the projection portion and the first electrode. As described above, the first electrode may be formed. According to this aspect, the head portion can be more easily driven by the lever principle.

  In another aspect of the embodiment of the probe of the present invention, at least a part of the head portion can be bent.

  According to this aspect, at least a part of this bendable can be driven (curved) suitably or locally by the electrostatic force applied between the first electrode and the second electrode.

  In another aspect of the embodiment of the probe of the present invention, the protrusion is formed such that the protrusion extends in the normal direction of the surface at least when the electric field is not applied.

  According to this aspect, for example, when the surface of the medium is not moved (for example, at the time of recording operation or reproducing operation), the protrusion can be extended in the normal direction of the surface of the medium. For example, if the tip of the protrusion has a substantially spherical cone or pyramid shape, the central axis of the protrusion intersects substantially perpendicularly to the surface of the medium. As a result, various suitable operations can be realized as described later.

  In another aspect of the embodiment of the probe of the present invention, the electric field is directly applied between the first electrode and the second electrode without passing through the medium.

  According to this aspect, an alternating electric field (or high-frequency electric field) applied between the protrusion and the return electrode described later at the time of data reproduction, or an electrode included in the protrusion and the dielectric recording medium described later at the time of data recording. An electric field can be suitably applied between the first electrode and the second electrode regardless of the electric field applied between the first electrode and the second electrode. Thereby, it becomes possible to drive a head part suitably.

  Another aspect of the embodiment of the probe of the present invention includes an electric field applying unit that applies the electric field.

  According to this aspect, the head unit can be suitably driven according to the operation of the electric field applying unit.

  In another aspect of the embodiment of the probe of the present invention, the first electrode and the second electrode are adjacent to each other.

  According to this aspect, the closer the first electrode and the second electrode are, the more electrostatic force can be applied between the first electrode and the second electrode. As a result, the head unit can be driven more quickly.

  In another aspect of the embodiment of the probe of the present invention, the head portion includes a conductive member.

  According to this aspect, since the electrostatic force is also applied between the head portion and the second electrode, the head portion can be suitably driven.

  In the case where the head portion has conductivity, the head portion can be moved against the surface of the medium by the electrostatic force generated between the second electrode and the head portion without providing the first electrode. It can be driven substantially in the vertical direction.

(Embodiment of recording apparatus)
An embodiment of the recording apparatus of the present invention is a recording apparatus for recording data on a dielectric recording medium, and includes the above-described embodiment of the probe of the present invention (including various aspects thereof), and the data Recording signal generation means for generating a corresponding recording signal.

  According to the embodiment of the recording apparatus of the present invention, data can be recorded based on the recording signal generated by the recording signal generating means while taking advantage of the above-described embodiment of the probe of the present invention. .

  Incidentally, in response to the various aspects of the embodiment of the probe of the present invention described above, the embodiment of the recording apparatus of the present invention can also adopt various aspects.

(Embodiment of playback device)
An embodiment according to the reproducing apparatus of the present invention is a reproducing apparatus for reproducing data recorded on a dielectric recording medium, and includes the above-described embodiment of the probe according to the present invention (including various aspects thereof), A high-frequency applying means for applying a high-frequency electric field to the dielectric recording medium; an oscillating means whose oscillation frequency changes according to a difference in capacitance corresponding to a nonlinear dielectric constant of the dielectric recording medium; and an oscillation signal from the oscillating means. And reproduction means for demodulating and reproducing the data.

  According to the embodiment of the reproducing apparatus of the present invention, a high frequency electric field is applied to the dielectric recording medium by the high frequency applying means, thereby causing a capacitance change corresponding to a change in the nonlinear dielectric constant of the dielectric recording medium. The oscillation frequency of the oscillation means changes. Then, the reproducing means demodulates and reproduces the oscillation signal corresponding to the change in the oscillation frequency by the oscillating means, thereby reproducing the data.

  Particularly in the present embodiment, data can be reproduced by taking advantage of the above-described embodiment of the probe of the present invention.

  Incidentally, in response to the various aspects of the embodiment of the probe of the present invention described above, the embodiment of the reproducing apparatus of the present invention can also adopt various aspects.

  Such an operation and other gains in this embodiment will be further clarified from examples described below.

  As described above, according to the embodiment of the probe of the present invention, the head portion, the first electrode, and the second electrode are provided. Therefore, the protrusion can be driven so as to come into contact with or away from the surface of the medium (that is, in the vertical direction with respect to the surface of the medium). In addition, the circuit configuration necessary for driving the probe can be made relatively easy.

  Moreover, according to the embodiment of the recording apparatus of the present invention, the probe and the recording signal generating means are provided. Therefore, various benefits of the embodiment of the probe of the present invention can be enjoyed.

  Moreover, according to the embodiment of the reproducing apparatus of the present invention, the probe, the high frequency applying means, the oscillating means, and the reproducing means are provided. Therefore, various benefits of the embodiment of the probe of the present invention can be enjoyed, and as a result, data can be reproduced more stably.

  Embodiments according to the probe of the present invention will be described below with reference to the drawings.

(1) Embodiment of Probe First, an embodiment according to the probe of the present invention will be described with reference to FIGS.

(I) Probe Structure First, with reference to FIG. 1 and FIG. 2, the probe structure (that is, the basic configuration) according to the present embodiment will be described. Here, FIGS. 1 and 2 are cross-sectional views conceptually showing an example of the structure of the probe according to the present embodiment.

  As shown in FIG. 1A, a probe 100 according to this embodiment includes a diamond tip 110, a support member 130, a diamond tip 110, and a support member 130, which are specific examples of the “projection” in the present invention. And a top plate 140 for supporting.

  The diamond tip 110 has a thin and sharp tip so that an electric field is applied to the dielectric recording medium 20 (see FIG. 22) described later from the tip side during the recording / reproducing operation of the probe 100. The diamond tip 110 preferably has a substantially spherical shape with a radius of the tip portion of approximately 10 nm to 25 nm, for example. In particular, the diamond tip 110 has conductivity by doping boron or the like into diamond at the time of manufacture.

  Instead of the diamond tip 110, for example, boron nitride can be used. Alternatively, any member that is relatively hard and conductive can be used in place of the diamond tip 110.

  The support member 130 serves as a base for supporting the diamond tip 110. Since the support member 130 serves as a path for supplying a current to the diamond tip 110, it is preferable that the support member 130 has conductivity. For example, it is preferable to include silicon (or silicon doped with an impurity such as boron) or diamond (or diamond doped with an impurity such as boron). However, for example, when the electrode and the diamond tip 110 are directly connected via a wiring or the like, the support member 130 does not have to be a current path, and thus may not have conductivity. These members can be used.

  Further, as will be described later, the support member 130 constitutes a part of the resonance circuit 14 during reproduction as a part of the probe 100 (see FIG. 22). For this reason, it is more preferable to select a material according to the inductance of the support member 130 so that a desired resonance frequency can be obtained. Moreover, the vibration frequency of the probe 100 can be appropriately changed by selecting the material in this way.

  The diamond tip 110 and the support member 130 correspond to a specific example of “head portion” in the present invention.

  The top plate 140 includes, for example, glass or the like, and supports the entire probe 100. By moving the top plate 140, the probe 100 is moved during operation of a recording / reproducing apparatus (see FIG. 21) described later.

  Particularly in the probe 100 according to the present embodiment, the first electrode 121 is formed on the support member 130, and the second electrode 122 is formed on the top plate 140. The probe 100 further includes a first wiring 151 for supplying current to the first electrode 121 and a second wiring 152 for supplying current to the second electrode 122. These electrodes and wirings contain, for example, metals such as chromium, silver, copper, gold, platinum, or alloys thereof.

  When the first electrode 121 and the second electrode 122 are supplied with current, an electrostatic force (Coulomb force) that is an attractive force is applied between these electrodes, and the support member 130 is driven (that is, curved). Can do.

  In particular, as compared with the distance between the first electrode 121 and the dielectric recording medium 20, the distance between the second electrode 122 and the dielectric recording medium 20 is longer (or longer). Each of the first electrode 121 and the second electrode 122 is formed. In other words, the second electrode 122 is formed on the upper side of the first electrode 121 (that is, on the side far from the dielectric recording medium 20). For this reason, the electrostatic force between the first electrode 121 and the second electrode 122 is applied in a generally vertical direction (that is, a direction substantially normal to the recording surface of the dielectric recording medium 20) in FIG. Since the electrostatic force is an attractive force, the first electrode 121 and the second electrode 122 are pulled together, and as a result, the support member 130 moves away from the dielectric recording medium 20 as shown in FIG. To bend.

  In other words, the electrostatic force applied between the first electrode 121 and the second electrode 122 is a direction excluding the direction parallel to the recording surface of the dielectric recording medium 20 (for example, the normal direction of the recording surface, Each of the first electrode 121 and the second electrode 122 is formed on the support member 130 or the top plate 140 so as to be suitably added to a direction having an angle of less than 90 degrees with respect to the normal line.

  Because of having such a configuration, an electrostatic force is applied between the first electrode 121 and the second electrode 122 unless current is supplied to each of the first electrode 121 and the second electrode 122. In other words, the diamond tip 110 (particularly, its tip) is preferably in contact with or close to the recording surface of the dielectric recording medium 20. On the other hand, if current is supplied to each of the first electrode 121 and the second electrode 122, an electrostatic force as an attractive force is applied between the first electrode 121 and the second electrode 122, so that the diamond chip 110 performs dielectric recording. It moves away from the recording surface of the medium 20.

  Thus, when data is recorded on the dielectric recording medium 20 or data recorded on the dielectric recording medium 20 is reproduced, the diamond tip 110 is preferably in contact with the recording surface of the dielectric recording medium 20. Therefore, an appropriate recording operation and reproduction operation can be realized. On the other hand, when data is not recorded or reproduced, the probe 100 can be suitably moved on the dielectric recording medium 20 without contacting the recording surface of the dielectric recording medium 20.

  Furthermore, since it is sufficient to form electrodes and wirings having a desired shape on the support member 130 and the top plate 140, for example, compared with a configuration in which the support member 130 is driven (curved) by the operation of an actuator circuit using a piezoelectric element. Thus, a relatively simple configuration can be realized. Furthermore, since the configuration of the electrodes and wirings can be simplified, the degree of freedom in designing each electrode and each wiring can be improved, so that a current is supplied to each electrode and each wiring and the diamond chip 110. Therefore, it is possible to reduce or eliminate crosstalk that may occur between the wiring and the like.

  In addition, in order to bend the support member 130 suitably (especially in the normal direction of the dielectric recording medium 20) by applying an electrostatic force, the whole or at least a part of the support member 130 is shown in FIG. As shown, for example, it is preferable to bend in advance to the side facing the dielectric recording medium 20. In other words, the support member 130 is curved in advance so that the portion of the support member 130 where the diamond tip 110 is formed is closer to the dielectric recording medium 20 than the portion of the support member 130 where the diamond tip 110 is not formed. It is preferable. In order to bend the support member 130 in advance in this way, the support member is curved in advance by mechanical or physical processing (for example, polishing processing or cutting processing by a dicer or the like, processing by an electron beam, a laser, or the like). 130 may be formed, or the support member 130 may be formed using a formwork or the like capable of forming a support member 130 that is curved in advance. Alternatively, a member having a lattice constant different from that used for the support member 130 is formed on the support member 130, and a support member 130 that is curved in advance is formed by applying compressive stress or tensile stress to the support member 130. May be. For example, if the support member 130 contains silicon, tensile stress can be applied to the support member 130 by SiN formed in a temperature environment of approximately 600 ° C. or higher, while the support member 130 is formed in a temperature environment of approximately 600 ° C. or less. Compressive stress can be applied to the support member 130 by SiN.

  Note that the first electrode 121 and the first wiring 151 may be used as a wiring for supplying a current to the diamond chip 110 during a recording operation or a reproducing operation. Alternatively, if the support member 130 has conductivity, the support member may be used as the first electrode 121 or the first wiring 151.

  The first electrode 121 is preferably formed at a position closer to the diamond tip 110. In addition to this, it is preferable that the first electrode 121 is formed at a position further away from the joint portion between the support member 130 and the top plate 140. Thus, the lever principle makes it easier to drive (bend) the support member 130, and the state in which the diamond tip 110 is in contact with or away from the dielectric recording medium 20 can be realized relatively easily. That is, it is preferable that the distance between the joint portion of the support member 130 corresponding to the fulcrum and the top plate 140 and the distance between the first electrode 121 corresponding to the action point be larger.

  Further, the present invention is not limited to a single probe as shown in FIGS. 1A and 1B, and a similar configuration may be adopted for a multi-probe including a plurality of diamond tips 110 and a plurality of support members 130.

  Furthermore, the electrostatic force applied between the first electrode 121 and the second electrode 122 is controlled by adjusting the magnitude of the current supplied to each of the first electrode 121 and the second electrode 122, and the support member 130. You may comprise so that the degree of curvature of may be adjusted. In particular, in a multi-probe including a plurality of diamond chips 110 and a plurality of support members 130, in order to realize a stable recording / reproducing operation, each probe is arranged so that each diamond chip 110 is simultaneously brought into contact with the recording surface. It is difficult to form. Therefore, by adjusting the magnitude of the current supplied to each of the first electrode 121 and the second electrode 122 to adjust the degree of curvature of each of the plurality of support members 130, the height of each diamond tip 110 is increased. Can be adjusted. That is, it is possible to relatively easily make each of the plurality of diamond tips 110 simultaneously contact the recording surface.

  As shown in FIG. 2A, instead of (or in addition to) bending the support member 130 in advance, the support member 130 has a predetermined angle with respect to the recording surface of the dielectric recording medium 20 in advance. The support member 130 may be attached to the top plate 140 so as to have (that is, to have an inclination). Even in this configuration, the diamond tip 110 is in contact with the recording surface of the dielectric recording medium 20 as shown in FIG. 2B due to the electrostatic force applied between the first electrode 121 and the second electrode 122. It is possible to realize a state without any problems. In other words, the support member 130 can be driven (curved) substantially vertically with respect to the recording surface of the dielectric recording medium 20. Accordingly, the probe 100a shown in FIGS. 2 (a) and 2 (b) can enjoy the same benefits as the various benefits of the probe 100 shown in FIGS. 1 (a) and 1 (b).

(Ii) Modified Example of Probe Next, with reference to FIGS. 3 and 4, a modified example of the probe according to the present embodiment will be described. FIG. 3 is a sectional view conceptually showing a first modification of the structure of the probe according to the present embodiment. FIG. 4 is a conceptual view showing a second modification of the structure of the probe according to the present embodiment. FIG.

  As shown in FIG. 3A, in the probe 100b according to the first modification, the respective electrodes are formed so as to have a positional relationship such that the first electrode 121 and the second electrode do not contact each other. That is, in the probe 100b according to the first modification, the first electrode 121 and the second electrode 122 are in contact with each other even if the support member 130 is bent by the electrostatic force applied between the first electrode 121 and the second electrode 122. Never do.

  As a result, the support member 130 is bent, so that the first electrode 121 and the second electrode 122 are in contact with each other, and as a result, a large current flows between the two electrodes and the probe 100b is damaged. It becomes possible. Furthermore, it is possible to prevent the inconvenience that the first electrode 121 and the second electrode 122 are not separated from each other due to the pull-in phenomenon due to the contact between the first electrode 121 and the second electrode 122.

  Furthermore, since it is necessary to consider the problem of contact between the first electrode 121 and the second electrode 122, the first electrode 121 and the second electrode 122 can be brought closer to each other. For this reason, a larger (or stronger) electrostatic force can be applied between the first electrode 121 and the second electrode 122. Thereby, the support member 130 can be driven (curved) more quickly.

  In addition, based on the strength of the support member 130, the ease of bending, or the breaking strength, an electrostatic force that suitably curves the support member 130 is applied between the first electrode 121 and the second electrode 122. You may comprise so that the distance between the 1st electrode 121 and the 2nd electrode 122 may be adjusted. When no electrostatic force is applied between the first electrode 121 and the second electrode, a line connecting the first electrode 121 and the second electrode 122 is a dielectric as shown in FIG. It is preferable not to be parallel to the recording surface of the body recording medium 20 (that is, not to intersect the normal line of the recording surface of the dielectric recording medium 20 at 90 degrees (ie, at right angles)). According to this structure, the electrostatic force is applied between the first electrode 121 and the second electrode 122, so that the support member 130 is driven (curved) substantially vertically with respect to the recording surface of the dielectric recording medium. be able to.

  When an electrostatic force is applied between the first electrode 121 and the second electrode 122, as shown in FIG. 3B, the first electrode 121 and the second electrode 122 are subjected to dielectric recording. It may have a positional relationship parallel to the recording surface of the medium.

  As shown in FIG. 4A, in the probe 100c according to the second modification, the support member 130 is curved in two stages in advance. That is, the support member 130 has a portion that curves in advance in a direction facing the dielectric recording medium 20 and a portion that curves in advance in a direction opposite to the direction facing the dielectric recording medium 20.

  Accordingly, when a recording operation or a reproducing operation is performed (for example, when no electrostatic force is applied), the diamond chip 110 is placed on the recording surface of the dielectric recording medium 20 as shown in FIG. It can be extended in a substantially vertical direction (that is, a normal direction of the recording surface). Therefore, a sharp tip (for example, a substantially spherical tip) of the diamond tip 110 is suitably recorded on the dielectric without increasing the actual contact area between the tip of the diamond tip 100 and the recording surface of the dielectric recording medium 20. It becomes possible to contact the medium 20.

  When an electrostatic force is applied between the first electrode 121 and the second electrode 122, the support member 130 is further curved as shown in FIG. 4B, and the diamond chip 110 and the dielectric recording medium 20 are separated. . Therefore, the probe 100c according to the second modification can also enjoy the various benefits described above.

  The various probes described with reference to FIGS. 1 to 3 can also be configured such that the diamond tip 110 extends in a direction perpendicular to the recording surface of the dielectric recording medium 20 during the recording operation and the reproducing operation. preferable.

(Iii) Probe Manufacturing Method Next, a probe manufacturing method according to the present embodiment will be described with reference to FIGS. FIG. 5 to FIG. 20 are sectional views conceptually showing each step of the method for manufacturing the probe according to this example.

First, as shown in FIG. 5, an SOI substrate (Silicon On Insulator) 61 is prepared. In the SOI substrate 61, an insulating layer 63 is formed on a base layer 62, a silicon layer 64 is formed on the insulating layer 63, and the surface of the silicon layer 64 is a processed surface 65. The silicon layer 64 is made of single crystal silicon and has a thickness of about 3.5 micrometers, for example. The insulating layer 63 is made of SiO ₂ and has a thickness of approximately 0.2 micrometers, for example.

  In a later step, it is preferable to prepare an SOI substrate 61 on which a silicon dioxide film is formed along (or in parallel with) the (100 plane) in the crystal lattice structure. This is because, as will be described later, by performing anisotropic etching, a diamond-shaped tip 110 (or pyramid) shape is formed (see FIG. 10).

Next, a mold hole 70 for forming the diamond chip 110 is formed in a part of the SOI substrate 61 from the processing surface 65 side toward the bottom surface side of the base layer 62 (mold hole forming step: FIG. 6 to FIG. 9). Specifically, as shown in FIG. 6, first, cover layers 66 and 67 are formed on the processing surface 65 and the bottom surface of the base layer 62. The cover layers 66 and 67 are made of SiO ₂ , and each thickness is thicker than the insulating layer 63, and is about 1 micrometer, for example. The cover layers 66 and 67 are formed by, for example, a thermal oxidation method.

  Subsequently, as shown in FIG. 7, a resist 68 is formed on the cover layer 66. Subsequently, the cover layer 66 is etched using the resist 68 as a mask to form a hole 69 in a part of the cover layer 66 as shown in FIG. This etching is desirably performed by FAB (Fast Atom Beam), hydrofluoric acid (HF), or buffered hydrofluoric acid (BHF). Thereafter, the resist 68 is removed.

  Subsequently, anisotropic etching is performed on the silicon layer 64 using the cover layer 66 in which the hole 69 is formed as a mask. For this etching, for example, tetramethyl ammonium hydroxide (TMAH) is used. Subsequently, the insulating layer 63 is etched using the cover layer 66 as a mask. This etching is desirably performed by FAB or HF. At this time, a part of the surface side of the cover layer 66 is also removed. However, since the cover layer 66 is thicker than the insulating layer 63, the cover layer 66 is not completely removed. Subsequently, anisotropic etching is performed on the base layer 62 using the cover layer 66 as a mask. This etching may be performed using TMAH. Thereby, as shown in FIG. 9, the mold hole 70 for shape | molding a diamond chip is formed.

Next, diamond is grown while mixing impurities (for example, boron) in the mold hole 70, thereby forming the diamond chip 110 (chip forming process: FIG. 10). Hereinafter, a preferable example of the method for forming the diamond tip 110 will be described. First, a solution in which diamond powder having a particle size of the order of micrometers is mixed with methanol or benzene, and the SOI substrate 61 in which the mold hole 70 is formed is immersed in the solution. Then, for example, the SOI substrate 61 immersed in the solution is allowed to stand for about 4 hours while applying ultrasonic waves by an ultrasonic generator (ultrasonic cleaner). As a result, scratches that trigger diamond growth are formed in the mold hole 70 and the surface of the cover layer 66 that have been in contact with the solution. Subsequently, diamond is grown by hot filament chemical vapor deposition (HF-CVD). At this time, H ₂ and methane are supplied to the growth reactor at a molar ratio of 3% of methane. At the same time, a small amount of trimethoxyborane, which is a raw material for boron, which is a p-type impurity, is supplied (about two digits lower than the number of moles of methane). Note that the growth of diamond in this step is limited to the extent that diamond does not become a film. Subsequently, the cover layer 66 is etched using buffered hydrofluoric acid or diluted HF, and a part of the surface side of the cover layer 66 is removed. Thereby, diamond grains grown on the cover layer 66 are also removed together with a part of the cover layer 66. Subsequently, boron-doped diamond is grown in the mold hole 70 by HF-CVD to form a diamond chip 110 as shown in FIG. Thereafter, the cover layer 66 is removed by etching.

Next, in the silicon layer 64, an impurity (for example, boron) is implanted to form a low resistance layer. Specifically, as shown in FIG. 11, the SiO ₂ cover layer 72 is formed again on the processed surface 65. The cover layer 72 serves to prevent the surface of the silicon layer 64 from being damaged by ion implantation and heat treatment performed in the subsequent steps. Subsequently, as shown in FIG. 12, using an ion implantation apparatus, boron is implanted into the surface of the silicon layer 64, and as shown in FIG. 13, the depth from the surface of the silicon layer 64 to about 0.8 micrometer is obtained. A boron doped layer 74 (low resistance layer) is formed in the region. Subsequently, heat is applied to the silicon layer 64 to cause p-type in the boron doped layer 74. Subsequently, the cover layers 67 and 72 are removed by etching. Thereby, as shown in FIG. 14, the support member 130 is formed.

  Note that the above-described steps (particularly, the low-resistance layer forming step) are not necessarily performed when it is not necessary to impart conductivity to the support member 130. In addition, if a boron doped layer 74 having a predetermined shape is formed by performing, for example, a desired patterning in accordance with the above-described steps, for example, a strain detection circuit or a signal processing circuit using a piezoresistive element can be simultaneously formed. Can do.

  Subsequently, as shown in FIG. 15, a SiN layer is formed on a part of the support member 130. This SiN layer is formed to curve the support member 130 in advance. For example, when the support member 130 is curved in advance to the side facing the dielectric recording medium 20 as in the probe 100 shown in FIGS. 1A and 1B, SiN is used in a relatively low temperature environment. Form a layer. More specifically, the substrate that supports the SOI substrate or the like is heated to approximately less than 600 ° C., and the SiN layer is formed by, for example, plasma CVD. Since the SiN layer formed by heating the substrate so as to be approximately less than 600 ° C. exerts a compressive stress on the silicon, the support member is formed simultaneously with or subsequent to the removal of the base layer 62 and the insulating layer 63 described later. 130 curves to the side facing the dielectric recording medium 20.

  Subsequently, as illustrated in FIG. 16, the first electrode 121 and a part of the first wiring 151 are formed on the support member 130 by an evaporation method, a sputtering method, or the like.

  Next, the top plate 140 is formed from the glass substrate shown in FIG. First, as shown in FIGS. 18 and 19, the glass substrate is processed using a dicer, sandblast, femtosecond laser, or the like. Thereby, the top plate 140 is formed.

  Subsequently, as shown in FIG. 20, another part of the second electrode 122, the second wiring 152, and the first wiring 151 is formed on the top plate 140. Here, these wirings or electrodes may be formed using, for example, a lift-off method. Note that the wiring and the electrode are not necessarily formed separately, and may be formed so that they are integrated.

  Subsequently, as shown in FIG. 21, the support member 130 and the top plate 140 are joined using a resin such as photosensitive polyimide. At this time, the first wiring 151 formed on the support member 130 and the first wiring 151 formed on the top plate 140 are electrically connected so that the support member 130 and the top are aligned with each other appropriately. It is preferable that the plate 140 is joined.

  Thereafter, etching is performed from the bottom side of the base layer 62 to remove the base layer 62 and the insulating layer 63. Specifically, the base layer 62 is etched by, for example, ICP-RIE, and the base layer 62 is removed. Subsequently, the insulating layer 63 is removed by etching the insulating layer 63 with buffered hydrofluoric acid (BHF), and then the whole is dried by supercritical drying. Thereby, the probe 100 etc. which concern on a present Example shown in FIG. 1 etc. can be manufactured.

  In particular, according to the manufacturing method described above, the diamond tip 110, the support member 130, and the top plate 140 can be distinguished and manufactured in separate steps. For this reason, the yield as the probe 100 whole can be improved.

(2) Embodiment of Recording / Reproducing Device Next, with reference to FIGS. 22 to 25, a recording / reproducing device using the probe according to the above-described embodiment will be described.

(I) Basic Configuration First, the basic configuration of the dielectric recording / reproducing apparatus in the example will be described with reference to FIG. FIG. 22 is a block diagram conceptually showing the basic structure of the dielectric recording / reproducing apparatus in the example.

  The dielectric recording / reproducing apparatus 1 includes a probe 100 that applies an electric field so that the tip of the diamond chip 110 faces the dielectric material 17 of the dielectric recording medium 20, and a high-frequency electric field for signal reproduction applied from the probe 100. The return electrode 12, the inductor L provided between the probe 100 and the return electrode 12, and the capacitance Cs of the part polarized corresponding to the recording information formed on the dielectric material 17 immediately below the inductor L and the probe 100. The oscillator 13 that oscillates at the resonance frequency determined by the above, the AC signal generator 21 for applying an alternating electric field for detecting the polarization state recorded on the dielectric material 17, and the polarization state are recorded on the dielectric material. A recording signal generator 22, a switch 23 for switching the output of the AC signal generator 21 and the recording signal generator 22, and HPF (High Pa s Filter) 24, a demodulator 30 that demodulates an FM signal modulated with a capacitance corresponding to the polarization state of the dielectric material 17 directly below the probe head 101, and a signal detector that detects data from the demodulated signal 34, a tracking error detection unit 35 that detects a tracking error signal from the demodulated signal, a drive circuit unit 40 that supplies current to each of the first electrode 121 and the second electrode 122 included in the probe 100, and the like. Is done.

  As the probe 100, the probe 100 according to this embodiment described above is used. The probe 100 is connected to the oscillator 13 via the HPF 24, and is connected to the AC signal generator 21 and the recording signal generator 22 via the HPF 24 and the switch 23. And it functions as an electrode for applying an electric field to the dielectric material 17. As the probe 100, for example, a needle-like one as shown in FIG. 1 or the like or a cantilever-like one is known as a specific shape.

  In this embodiment, the probe 100 (particularly, the diamond tip 110) may have a plurality of structures or a structure with only one probe. However, when a plurality of probes 100 are provided, it is preferable to provide a plurality of AC signal generators 21 corresponding to each probe 100. In addition, the signal detection unit 34 includes a plurality of signal detection units 34 so that the reproduction signals corresponding to the respective AC signal generators 21 can be discriminated, and each of the signal detection units 34 has each AC signal generator 21. It is preferable to obtain a reference signal and output a corresponding reproduction signal.

  The return electrode 12 is an electrode to which a high-frequency electric field (that is, a resonant electric field from the transmitter 13) applied from the probe 100 (particularly, the diamond head 110) to the dielectric material 17 returns, and is provided so as to surround the probe 100. It has been. If the high frequency electric field returns to the return electrode 12 without resistance, its shape and arrangement can be arbitrarily set.

  The inductor L is provided between the probe 10 and the return electrode 12, and is formed by, for example, a microstrip line. A resonance circuit 14 is configured including the inductor L and the capacitor Cs. The inductance of the inductor L is determined so that the resonance frequency becomes a value centered around about 1 GHz, for example.

  The oscillator 13 is an oscillator that oscillates at a resonance frequency determined by the inductor L and the capacitor Cs. The oscillation frequency changes corresponding to the change of the capacitance Cs, and therefore FM modulation is performed corresponding to the change of the capacitance Cs determined by the polarization region corresponding to the recorded data. By demodulating this FM modulation, the data recorded on the dielectric recording medium 20 can be read.

  As will be described in detail later, the resonance circuit 14 is constituted by the probe 100, the return electrode 12, the oscillator 13, the inductor L, the HPF 24, and the capacitance Cs in the dielectric material 17, and the FM signal amplified by the oscillator 13 is obtained. It is output to the demodulator 30.

  The AC signal generator 21 is a specific example of the “high frequency applying means” in the present invention, and applies an alternating electric field between the return electrode 12 and the electrode 16. Further, in a dielectric recording / reproducing apparatus including a plurality of probes 100, synchronization is performed using this frequency as a reference signal, and signals detected by the probe 10 are discriminated. The frequency is centered around about 5 kHz, and an alternating electric field is applied to a minute region of the dielectric material 17.

  The recording signal generator 22 generates a recording signal and supplies it to the probe 100 during recording. This signal is not limited to a digital signal but may be an analog signal. These signals include various signals such as audio information, video information, and digital data for computers. Also, the AC signal superimposed on the recording signal is for discriminating and reproducing the information of each probe as a reference signal at the time of signal reproduction.

  The switch 23 selects the output so that the signal from the AC signal generator 21 is supplied to the probe 100 during reproduction, while the signal from the recording signal generator 22 is supplied to the probe 100 during recording. This apparatus uses a mechanical relay or a semiconductor circuit, but it is preferable that a relay is used for an analog signal and a semiconductor circuit is used for a digital signal.

  The HPF 24 includes an inductor and a capacitor, and is used to configure a high-pass filter for cutting off the signal system so that signals from the AC signal generator 21 and the recording signal generator 22 do not interfere with the oscillation of the oscillator 13. The cutoff frequency is f = 1 / 2π√ {LC}. Here, L is the inductance of the inductor included in the HPF 24, and C is the capacitance of the capacitor included in the HPF 24. Since the frequency of the AC signal is about 5 KHz and the oscillation frequency of the oscillator 13 is about 1 GHz, separation is sufficiently performed by the primary LC filter. Further, a filter having a higher order may be used. However, since the number of elements increases, there is a possibility that the apparatus becomes large.

  The demodulator 30 demodulates the oscillation frequency of the oscillator 13 that has been FM-modulated due to a minute change in the capacitance Cs, and restores the waveform corresponding to the polarized state of the portion traced by the probe 100. If the recorded data is digital “0” and “1” data, there are two types of frequencies to be modulated, and data can be easily reproduced by determining the frequencies.

  The signal detector 34 reproduces the recorded data from the signal demodulated by the demodulator 30. For example, a lock-in amplifier is used as the signal detector 34, and data is reproduced by performing synchronous detection based on the frequency of the alternating electric field of the AC signal generator 21. Of course, other phase detection means may be used.

  The tracking error detection unit 35 detects a tracking error signal for controlling the apparatus from the signal demodulated by the demodulator 30. The detected tracking error signal is input to the tracking mechanism and controlled.

  The drive circuit unit 40 is a specific example of the “electric field applying unit” in the present invention, and a current is supplied to the first electrode 121 and the second electrode 122 via the first wiring 151 and the second wiring 152 (not shown). It is configured to be able to supply. In particular, the current value and voltage value of the supplied current or the time and timing of supplying the current can be appropriately controlled.

  Next, an example of the dielectric recording medium 20 shown in FIG. 22 will be described with reference to FIG. FIG. 23 is a plan view and a cross-sectional view conceptually showing an example of the dielectric recording medium 20 used in this embodiment.

  As shown in FIG. 23A, the dielectric recording medium 20 is a disk-shaped dielectric recording medium, for example, a center hole 10 and an inner peripheral area 7 and a recording area concentrically with the center hole 10 from the inside. 8. An outer peripheral area 9 is provided. The center hole 10 is used when mounted on a spindle motor.

  The recording area 8 is an area for recording data, and has a track and a space between tracks, and an area for recording control information related to recording and reproduction is provided in the track and the space. Further, the inner peripheral area 7 and the outer peripheral area 8 are used for recognizing the inner peripheral position and the outer peripheral position of the dielectric recording medium 20, and information relating to data to be recorded, such as a title, its address, recording time, recording capacity, etc. Can also be used as a recording area. The above-described configuration is an example thereof, and other configurations such as a card form can be adopted.

  Further, as shown in FIG. 23B, the dielectric recording medium 20 is formed by laminating an electrode 16 on a substrate 15 and a dielectric material 17 on the electrode 16.

  The substrate 15 is, for example, Si (silicon), and is a material suitable for its strength, chemical stability, workability, and the like. The electrode 16 is for generating an electric field with the probe 100 (or the return electrode 12), and the polarization direction is determined by applying an electric field higher than the coercive electric field to the dielectric material 17. Recording is performed by determining the polarization direction corresponding to the data.

The dielectric material 17 is formed by, for example, a known technique such as sputtering of LiTaO ₃ that is a ferroelectric material on the electrode 16. Recording is performed on the Z plane of LiTaO ₃ in which the + plane and the − plane of polarization have a 180-degree domain relationship. Of course, other dielectric materials may be used. The dielectric material 17 forms minute polarization at a high speed by a data voltage applied simultaneously with a DC bias voltage.

  Further, the shape of the dielectric recording medium 20 includes, for example, a disk form and a card form. The relative position with respect to the probe 100 is moved by the rotation of the medium, or one of the probe 100 and the medium is moved linearly.

(Ii) Operation Principle Next, with reference to FIGS. 24 and 25, the operation principle of the dielectric recording / reproducing apparatus 1 in the example will be described. In the following description, some components of the dielectric recording / reproducing apparatus 1 shown in FIG. 22 are extracted and described.

(Recording operation)
First, the recording operation of the dielectric recording / reproducing apparatus in the example will be described with reference to FIG. FIG. 24 is a sectional view conceptually showing the information recording operation.

  As shown in FIG. 24, by applying an electric field higher than the coercive electric field of the dielectric material 17 between the probe 100 and the electrode 16, the dielectric material has a direction corresponding to the direction of the applied electric field and is polarized. . Then, predetermined information can be recorded by controlling the applied voltage and changing the direction of polarization. This utilizes the property that when an electric field exceeding the coercive electric field is applied to a dielectric (particularly a ferroelectric), the polarization direction is reversed and the polarization direction is maintained in a state.

  For example, it is assumed that when an electric field directed from the probe 100 to the electrode 16 is applied, the minute region becomes a downward polarization P, and when an electric field directed from the electrode 16 to the probe 100 is applied, the polarization becomes an upward polarization P. This corresponds to a state where information is recorded. When the probe 100 is operated in the direction indicated by the arrow, the detection voltage is output as a rectangular wave that swings up and down corresponding to the polarization P. This level changes depending on the degree of polarization of the polarization P, and recording as an analog signal is also possible.

  In this embodiment, in particular, the probe 100 according to the above-described embodiment is used. For this reason, an electrostatic force is applied between the first electrode 121 and the second electrode 122 by the current supplied from the drive circuit unit 40. As a result, the support member 130 can be driven (curved) substantially in the normal direction of the recording surface of the dielectric recording medium 20. Accordingly, when data is recorded on the dielectric recording medium 20, the diamond chip 110 is preferably in contact with the recording surface of the dielectric recording medium 20, so that an appropriate recording operation can be realized. On the other hand, when data is not recorded, the probe 100 can be suitably moved on the dielectric recording medium 20 without contacting the recording surface of the dielectric recording medium 20.

(Playback operation)
Next, with reference to FIG. 25, the reproducing operation of the dielectric recording / reproducing apparatus 1 in the example will be explained. FIG. 25 is a cross-sectional view conceptually showing the information reproducing operation.

  The nonlinear dielectric constant of the dielectric changes corresponding to the polarization direction of the dielectric. The nonlinear dielectric constant of the dielectric can be detected as a difference in capacitance or a change in capacitance when an electric field is applied to the dielectric. Therefore, by applying an electric field to the dielectric material and detecting a difference in capacitance Cs or a change in capacitance Cs in a certain minute region of the dielectric material at that time, it is recorded as the direction of polarization of the dielectric material. It is possible to read and play back the data.

  Specifically, first, as shown in FIG. 25, an alternating electric field from an AC signal generator 21 (not shown) is applied between the electrode 16 and the probe 100. This alternating electric field has an electric field strength that does not exceed the coercive electric field of the dielectric material 17, and has a frequency of, for example, about 5 kHz. The alternating electric field is generated primarily to allow identification of the difference in capacitance change corresponding to the polarization direction of the dielectric material 17. Note that an electric field may be formed in the dielectric material 17 by applying a DC bias voltage instead of the alternating electric field. When such an alternating electric field is applied, an electric field is generated in the dielectric material 17 of the dielectric recording medium 20.

  Next, the probe 100 is moved closer to the recording surface until the distance between the tip of the probe 100 and the recording surface becomes a very small distance on the nano order. In this state, the oscillator 13 is driven. In order to detect the capacitance Cs of the dielectric material 17 immediately below the probe 100 with high accuracy, the probe 100 is preferably brought into contact with the surface of the dielectric material 17, that is, the recording surface. However, in order to read the data recorded on the dielectric material 17 at high speed, it is necessary to relatively move the probe 100 on the dielectric recording medium 20 at high speed. Therefore, considering the feasibility of such high-speed movement and the prevention of damage due to collision / friction between the probe 100 and the dielectric recording medium 20, the probe 100 is substantially regarded as contact rather than contacting the recording surface. It is better to bring the probe 100 as close to the recording surface as possible.

  The oscillator 13 oscillates at the resonance frequency of the resonance circuit including the capacitor Cs and the inductor L related to the dielectric material 17 immediately below the probe 100 as constituent factors. As described above, this resonance frequency has a center frequency of about 1 GHz.

  Here, the return electrode 12 and the probe 100 constitute a part of the oscillation circuit 14 by the oscillator 13. A high frequency signal of about 1 GHz applied from the probe 100 to the dielectric material 17 passes through the dielectric material 17 and returns to the return electrode 12 as indicated by a dotted arrow in FIG. By providing the return electrode 12 in the vicinity of the probe 100 and shortening the feedback path of the oscillation circuit including the oscillator 13, it is possible to reduce noise (for example, stray capacitance component) from entering the oscillation circuit.

  In other words, the change in the capacitance Cs corresponding to the nonlinear dielectric constant of the dielectric material 17 is minute, and in order to detect this, it is necessary to employ a detection method having high detection accuracy. Although the detection method using FM modulation can generally obtain high detection accuracy, it is necessary to further improve detection accuracy in order to enable detection of a minute capacitance change corresponding to the nonlinear dielectric constant of the dielectric material 17. There is. Therefore, the dielectric recording / reproducing apparatus 1 according to the present embodiment (that is, the recording / reproducing apparatus using the SNDM principle) arranges the return electrode 12 in the vicinity of the probe 100 and shortens the feedback path of the oscillation circuit as much as possible. Yes. Thereby, extremely high detection accuracy can be obtained, and a minute capacitance change corresponding to the nonlinear dielectric constant of the dielectric can be detected.

  After driving the oscillator 13, the probe 100 is moved on the dielectric recording medium 20 in a direction parallel to the recording surface. Then, due to the movement, the domain of the dielectric material 17 immediately below the probe 100 changes, and the capacitance Cs changes whenever the polarization direction changes. When the capacitance Cs changes, the resonance frequency, that is, the oscillation frequency of the oscillator 13 changes. As a result, the oscillator 13 outputs an FM-modulated signal based on the change in the capacitance Cs.

  This FM signal is frequency-voltage converted by the demodulator 30. As a result, the change in the capacitance Cs is converted into a voltage magnitude. The change in the capacitance Cs corresponds to the nonlinear dielectric constant of the dielectric material 17, and this nonlinear dielectric constant corresponds to the polarization direction of the dielectric material 17, and this polarization direction is the data recorded in the dielectric material 17. Correspond. Therefore, the signal obtained from the demodulator 30 is a signal whose voltage changes corresponding to the data recorded on the dielectric recording medium 20. Further, the signal obtained from the demodulator 30 is supplied to the signal detection unit 34 and, for example, synchronously detected, the data recorded on the dielectric recording medium 20 is extracted.

  At this time, in the signal detection unit 34, the AC signal generated by the AC signal generator 21 is used as a reference signal. Thereby, for example, even if the signal obtained from the demodulator 30 contains a lot of noise or the data to be extracted is weak, the data is extracted with high accuracy by synchronizing with the reference signal as described later. It becomes possible.

  In this embodiment, in particular, the probe 100 according to the above-described embodiment is used. For this reason, when reproducing the data recorded on the dielectric recording medium 20, the diamond chip 110 is preferably in contact with the recording surface of the dielectric recording medium 20, so that an appropriate reproducing operation can be realized. On the other hand, when data is not recorded, the probe 100 can be suitably moved on the dielectric recording medium 20 without contacting the recording surface of the dielectric recording medium 20.

  In the above-described embodiments, the dielectric material 17 is used for the recording layer. From the viewpoint of nonlinear dielectric constant and spontaneous polarization, the dielectric material 17 is preferably a ferroelectric material.

  In the above-described embodiment, the example in which the probe 100 is used as a dielectric recording medium has been described. However, the usage of the probe 100 is not limited to this. For example, data is recorded on various recording media or recorded on various recording media. It can also be used in a recording / reproducing apparatus that reproduces recorded data, or various microscopes such as AFM.

  In addition, the present invention can be appropriately changed without departing from the gist or the idea of the invention that can be read from the claims and the entire specification, and the probe, recording apparatus, and reproducing apparatus accompanying such a change are also included in the present invention. It is included in the technical idea of the invention.

It is the side view and top view which show one specific example of the Example which concerns on the probe of this invention notionally. It is a top view which shows notionally the other specific example of the Example which concerns on the probe of this invention. It is a top view which shows notionally the other specific example of the Example which concerns on the probe of this invention. It is a top view which shows notionally the specific advantage of the probe which concerns on a comparative example. It is sectional drawing which shows notionally one process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is sectional drawing which shows notionally the other process of the manufacturing method of the Example which concerns on the probe of this invention. It is a block diagram which shows notionally the basic composition of the Example concerning the dielectric recording / reproducing apparatus which employ | adopts the Example concerning the probe of this invention. 2A and 2B are a plan view and a cross-sectional view conceptually showing a dielectric recording medium used for reproduction of the dielectric recording / reproducing apparatus in the example. It is sectional drawing which shows notionally recording operation | movement of the dielectric recording / reproducing apparatus based on an Example. It is sectional drawing which shows notionally the reproducing operation of the dielectric recording / reproducing apparatus based on an Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Dielectric recording / reproducing apparatus 13 ... Oscillator 14 ... Resonant circuit 16 ... Electrode 17 ... Dielectric material 20 ... Dielectric recording medium 21 ... AC signal generator 22. ..Recording signal generator 40 ... Drive circuit unit 100 ... Probe 110 ... Diamond tip 121 ... First electrode 122 ... Second electrode 130 ... Support member 140 ... Top plate

Claims (4)

A probe for scanning the surface of a medium,
A head portion including a protrusion having a tip facing the medium;
A first electrode formed on at least a part of the head portion;
A second electrode for applying an electric field between the first electrode and
The first electrode is disposed in another region excluding one region where the second electrode is disposed as viewed from the normal direction of the surface,
The head portion is bendable so that a difference between a height of the first electrode and a height of the second electrode with respect to the surface decreases when the electric field is applied. probe. 2. The probe according to claim 1, wherein when the electric field is applied to the head unit, a difference between a height of the first electrode and a height of the second electrode is eliminated.   By applying the electric field, the second electrode is formed so that an electrostatic force having a component in a direction parallel to the surface of the medium is generated between the first electrode and the second electrode. The probe according to claim 1 or 2, characterized in that:   The probe according to claim 3, wherein a component of the electrostatic force parallel to the surface of the medium is larger than a component perpendicular to the surface of the medium.

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