JP4908364B2 - Probe array type storage device - Google Patents

Description

  The present invention relates to a storage apparatus including a recording / reproducing head using a plurality of probe arrays, and to correcting rotational deviation in a storage apparatus including a micro XY stage having two degrees of freedom with respect to movement in a plane (in the XY plane). Related to the mechanism.

  With the development of the information society, the demand for large capacity memory technology is increasing. In recent years, a scanning tunneling microscope (STM) capable of observing the surface of a conductive material with a resolution of nanometer or less has been developed. In addition, STM technology has been developed, and an atomic force microscope (AFM) and a near-field optical microscope (NFOM) that can observe the surface of an insulating material or the like with the same resolution as STM have been developed. A proposal has been made to realize a high-density memory by applying the principle such as STM, AFM, NFOM, etc., and performing recording / reproduction by accessing a recording medium on an atomic / molecular scale using a probe.

  Further, for the purpose of downsizing, an apparatus has been proposed in which a plurality of probe electrodes are formed on a semiconductor substrate, and a recording medium facing the same is displaced to perform recording and reproduction.

When recording is performed by scanning a recording medium with a probe array head having a plurality of probe electrodes, the direction in which recording is to be performed on the recording medium and the actual scanning direction of the probe electrodes must match. The same applies to reproduction by scanning the recording medium with the probe array head. However, due to temperature variation, aging deterioration, and the like, the elastic support portion that supports the recording medium is affected, and so-called “rotational deviation” may occur in the recording medium (recording medium). In this case, at the time of recording / reproduction, there is a problem that the direction in which recording or reproduction is to be performed on the recording medium does not coincide with the actual scanning direction of the probe electrode. For example, Patent Document 1 below describes that correction is performed by a rotation mechanism using a motor in order to solve this problem.
Patent No. 3042817

  However, the rotation mechanism using the motor of Patent Document 1 has a problem that the size of the entire apparatus becomes large and the power consumption required to drive the rotation mechanism cannot be kept low.

  The present invention has been made in view of such problems, and an object of the present invention is to provide a probe array type storage apparatus having a simple structure, a small size, and a rotation correction mechanism with low power consumption. .

  A probe array type storage apparatus according to an aspect of the present invention includes a recording medium for recording information, and a plurality of probe electrodes for writing to or reading from the recording medium, and a probe provided to face the recording medium An array, a first comb electrode actuator that relatively moves the recording medium and the probe array along a first direction parallel to a plane of the recording medium, and a first crossing the first direction. A plurality of second comb electrode actuators that move the recording medium and the probe array relative to each other along two directions and can be controlled independently from each other; and between the recording medium and the probe array Control means for controlling the driving of each of the plurality of second comb electrode actuators so as to eliminate the positional deviation.

  According to the present invention, it is possible to provide a probe array type storage apparatus having a simple structure, a small size, and a rotation correction mechanism with low power consumption.

  Hereinafter, a probe array type storage apparatus according to an embodiment of the present invention will be described with reference to the drawings.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a perspective view showing an outline of the internal structure of the probe array type storage apparatus. As shown in the figure, a probe array type storage apparatus according to an embodiment of the present invention includes a probe array 1 having a plurality of probe electrodes, a recording medium (recording medium) 2 for recording information, and a recording medium 2. Electrostatically driven comb electrode actuators 3a and 3b for driving the probe array 1 and the recording medium 2 relative to each other along at least two axial directions parallel to the surface, and an electrostatically driven comb electrode actuator 3a , 3b, elastic support portions (beams) 4a and 4b for supporting the recording medium 2 driven by the external frame 5 by using elasticity.

  In the two axial directions in which the probe array 1 and the recording medium 2 are relatively moved, the recording medium 2 is driven by the electrostatically driven comb electrode actuator 3a in the first axial direction. This first axial direction is referred to as “driving axis direction”. The other second axis direction is orthogonal to the drive axis direction, and this direction is referred to as a “control axis direction”. In the control axis direction, the drive of the recording medium 2 is performed by the electrostatic drive comb electrode actuator (control axis) 3b.

  A portion composed of the recording medium 2, electrostatic drive comb electrode actuators 3a and 3b, and elastic support portions 4a and 4b is referred to as a “micro XY stage”. The micro XY stage has a degree of freedom in two directions with respect to movement in a plane (in the XY plane).

  The probe array 1 that performs writing and reading is arranged to face the recording medium 2. When recording or reproduction is performed by scanning the recording medium 2 using the probe array 1, the direction to be recorded or reproduced on the recording medium 2 and the scanning direction of the probe array 1 are made to coincide with each other. Thus, it is necessary to position each head (tip of each probe) of the probe array 1. However, the elastic support portions 4a and 4b that support the recording medium 2 are affected by temperature variations, aging deterioration, and the like, and a rotational deviation occurs between the relative positions of the recording medium 2 and the probe array 1, as shown in FIG. In some cases, the direction to be recorded on or reproduced from the recording medium 2 does not match the scanning direction of the probe array 1.

  Therefore, in the embodiment of the present invention, the electrostatic drive comb electrode actuator 3b responsible for the feed drive in the control axis direction is divided into at least two or more so that they can be driven independently from each other. By appropriately controlling each of the comb electrode actuators 3b, the recording medium 2 is rotated for correcting the rotational deviation by the driving force.

FIG. 3 shows the structure of each layer in the case where a micro XY stage including the recording medium 2, the elastic support portions 4a and 4b, and the electrostatic drive comb electrode actuators 3a and 3b is manufactured using an SOI substrate. This SOI substrate has a three-layer structure of an Si upper layer 6, a SiO ₂ layer (insulating layer) 7 and a Si lower layer 8. For the recording medium 2, it is necessary to form a film suitable for the recording medium on the Si upper layer 6. As can be seen from FIG. 3A, the electrostatic drive comb electrode actuator 3b is divided into electrostatic drive comb electrode actuators 3b _UL , 3b _UR , 3b _DL , and 3b _DR , respectively. Can be driven.

FIG. 4 is a diagram showing the structural relationship of the micro XY stage. The Si lower layer 8 and the SiO ₂ layer 7 constitute an electrostatic drive comb electrode actuator 3a for the drive shaft and an elastic support portion 4a for the drive shaft having a serpentine (meandering) shape. When driving is performed by the electrostatic drive comb electrode actuator 3a, the relative position of the movable portion 11 with respect to the fixed portions 9 and 10 changes along the drive axis direction as shown in FIG. Further, the Si upper layer 6 and the SiO ₂ layer 7 constitute the electrostatic drive comb electrode actuator 3b for the control shaft, the elastic support portion 4b for the control shaft having a serpentine shape, and the recording medium 2. ing. When driving is performed by the electrostatically driven comb electrode actuator 3b, the relative position of the movable portion 12 with respect to the fixed portion 11 changes along the control axis direction as shown in FIG. 4B. The electrostatic drive comb electrode actuator 3b for the control axis has a structure in which the fixed electrode portion is divided into 3b _UL , 3b _UR , 3b _DL , and 3b _DR .

FIG. 5 is a diagram showing an electrical relationship (the same potential) of the micro XY stage. As for the electrostatic drive comb electrode actuator 3b for the control shaft, the fixed electrode portion is divided into 3b _UL , 3b _UR , 3b _DL , 3b _DR as shown in FIG. Each part (hereinafter referred to as V _UL electrode, V _UR electrode, V _DL electrode, and V _DR electrode) can be driven by applying different voltages.

  FIG. 6 is a diagram for explaining the relationship between the voltages applied to the electrostatic drive comb electrode actuators 3b when the rotation correction is performed by the micro XY stage.

A control unit (not shown) performs control for the rotation correction, for example in order to rotate the recording medium 2 in the counterclockwise direction, by applying further added a constant voltage to V _UR electrode and V _DL electrode, the actuator driving the To be done. By increasing the applied voltage, the electrostatically driven comb electrode actuators of the _VUR electrode and the _VDL electrode are attracted more, and this becomes a rotational force. In FIG. 6, this is shown as (V _UL , V _UR , V _DR , V _DL ) = (0, 1, 1, 0). Note that the same result can be obtained even if driving is performed by further reducing the constant voltage from the _VUL electrode and the _VDR electrode.

Similarly, when rotating the recording medium 2 clockwise, the control unit further applies a constant voltage to the V _UL electrode and the V _DR electrode. In FIG. 6, this is shown as (V _UL , V _UR , V _DR , V _DL ) = (1, 0, 0, 1). Note that the same result can be obtained even if driving is performed by further reducing and applying a constant voltage from the _VUR electrode and the _VDL electrode.

In addition, in order to translate the recording medium 2 in the control axis direction, the control unit drives the V _UL electrode and the V _UR electrode, or the V _DL electrode and the V _DR electrode by further applying a constant voltage, or further reduces the constant voltage. Drive.

  It should be noted that the detection of the occurrence of rotational deviation and the amount of deviation may be performed by an arbitrary configuration. For example, it may be performed by detecting a change in the area of the overlapping area between the probe array 1 and the recording medium 2 using a capacitance sensor arranged at a predetermined position (for example, Patent Document 1).

  Alternatively, detection by a thermal displacement sensor described in a reference (M.A. Lantz, G.K. Binnig, M. Despont and Drechsler, "A micromechanical thermal displacement sensor with nanometer resolution", IBM Zurich Research Laboratory) may be performed.

  When the occurrence of rotation deviation is detected, rotation correction is executed by controlling the rotation mechanism of this embodiment until the amount of rotation deviation becomes zero.

  Alternatively, the control unit may perform appropriate rotation correction based on feedback information for positioning between the probe array 1 and the recording medium 2.

  Therefore, when the rotational deviation occurs in the relative position between the recording medium 2 and the probe array 1 and the direction in which recording or reproduction is to be performed on the recording medium 2 and the scanning direction of the probe array 1 do not match, the divided control is performed. The recording medium 2 can be rotationally driven by individually applying voltage to the electrostatic drive comb electrode actuator 3b for the shaft, and thus rotation correction can be performed. In addition, the rotation mechanism of the present embodiment has an advantage that it has a simpler structure and is smaller than a rotation mechanism using a motor or the like, and is small in power consumption.

  In the present embodiment, the recording medium 2 is elastically supported and driven by an actuator. However, since the purpose is to move the recording medium 2 and the probe array 1 relative to each other, the recording medium 2 is not driven. Alternatively, the probe array 1 may be elastically supported and driven. Further, not only for the control axis but also for the electrostatic drive comb electrode actuator 3a for the drive axis, it may be divided so that it can be driven independently.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG. The second embodiment relates to a modification of the first embodiment described with reference to FIGS.

  FIG. 7 is a diagram for explaining the relationship of the voltage applied to each electrostatically driven comb electrode actuator 3b when the rotation correction is performed by the micro XY stage. The second embodiment has a structure in which the fixed electrode portion of the electrostatic drive comb electrode actuator 3b for the control axis is divided into three, and can be driven by applying different voltages to the respective electrodes. .

For example, when the control unit (not shown) rotates the recording medium 2 counterclockwise, it is driven by further applying a constant voltage to the _VUR electrode and the _VDL electrode. In FIG. 7, this is shown as (V _UL , V _UC , V _UR , V _DL , V _DC , V _DR ) = (0, 0, 1, 1, 0, 0). Note that the same result can be obtained even if driving is performed by reducing a constant voltage applied from the V _UR electrode and the V _DL electrode.

Similarly, in order to rotate the recording medium 2 clockwise, a constant voltage is further applied to the V _UL electrode and the V _DR electrode. In FIG. 7, this is shown as (V _UL , V _UC , V _UR , V _DL , V _DC , V _DR ) = (1, 0, 0, 0, 0, 1). Note that the same result can be obtained even if driving is performed by reducing the constant voltage applied from the V _UL electrode and the V _DR electrode.

Also, when translating in the control axis direction, a constant voltage is further applied to the V _UC electrode, V _UR electrode, V _UC electrode, V _UL electrode, V _DC electrode, or V _DR electrode, V _DC electrode, and V _DL electrode. In addition, the driving may be performed or the constant voltage may be further reduced.

  Thus, in the second embodiment in which the fixed electrode portion of the electrostatic drive comb electrode actuator 3b for the control axis is divided into three, the electrostatic drive comb electrode actuator for rotation and the electrostatic for translation Since the driving comb electrode actuator can be divided, it can be expected that the controllability is good.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

The perspective view which shows the outline of the internal structure of a probe array type storage apparatus Diagram for explaining rotational deviation in probe scanning direction The figure which shows the structure of each layer in the case of producing a microXY stage with an SOI substrate The figure which shows the structural relationship of the micro XY stage The figure which shows the electrical relationship (same electric potential) of a microXY stage The figure for demonstrating the relationship of the voltage applied to each electrostatic drive comb electrode actuator in the case of performing rotation correction with a micro XY stage The figure for demonstrating the relationship of the applied voltage to each electrostatic drive comb-tooth electrode actuator in the case of performing rotation correction by the micro XY stage according to the second embodiment of the present invention.

Explanation of symbols

1 ... Probe array;
2 ... Recording medium (recording medium);
3a: electrostatic drive comb electrode actuator (drive shaft);
3b: Electrostatically driven comb electrode actuator (control axis);
4a: elastic support (beam) (drive shaft);
4b ... elastic support part (beam) (control axis);
5 ... External frame

Claims (6)

A recording medium for recording information;
A plurality of probe electrodes for writing to or reading from the recording medium, and a probe array provided facing the recording medium;
A first comb electrode actuator having electrodes facing each other and relatively moving the recording medium and the probe array along a first direction parallel to a plane of the recording medium;
A plurality of electrodes are arranged on each of two sides facing each other across the center of the recording medium or the probe array, which are arranged in a plane on the z axis different from the plane on which the first comb electrode actuator is arranged. many have a first second along said direction of the recording medium and the second multiple of the probe array Ru is relatively moved comb electrodes actuator intersecting direction,
Control means for controlling the driving of each of the plurality of second comb electrode actuators so as to eliminate the positional deviation between the recording medium and the probe array ;
The direction of the electrode of the first comb electrode actuator intersects the direction of the electrode of the second comb electrode actuator,
A probe array type storage device capable of relatively rotating the recording medium and the probe array .   The probe array type storage apparatus according to claim 1, wherein the control unit performs control so that the recording medium and the probe array rotate relatively.   The probe array type storage apparatus according to claim 1, wherein the control unit performs control so that the recording medium and the probe array move relatively in parallel.   4. The probe array type storage apparatus according to claim 1, wherein the control unit obtains the displacement amount based on feedback information for positioning between the probe array and the recording medium. 5.   By controlling a pair of second comb electrode actuators in a positional relationship facing each other across the center of the recording medium or the probe array among the plurality of second comb electrode actuators, 3. The probe array type storage apparatus according to claim 2, wherein a rotational force for rotating the probe array relatively is obtained. The plurality of second comb electrode actuators include a left comb electrode actuator, a center comb electrode actuator, and a right side on one of two sides facing each other across the center of the recording medium or the probe array. The comb electrode actuator is divided into
The left and right comb electrode actuators are used to relatively rotate the recording medium and the probe array, and the center comb electrode actuator is configured to relatively parallel the recording medium and the probe array. The probe array type storage apparatus according to claim 1, which is used for movement.

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