JPH04351763A - Information processing method and information processor - Google Patents

Abstract

PURPOSE:To judge a damage of probe to be capable of processing, and to improve reliability by reproducing the same place on a recording medium plural times by the probe, comparing and processing each other informations obtained in the different times, and confirming the condition of probe. CONSTITUTION:The recording is made by impressing a pulse voltage of a voltage impressing circuit 13 with the control of a control circuit 9 while scanning the recording medium 3 by the probe 5. The voltage of 1V is impressed between the probe 5 and a base electrode 2 of the medium 3, and the probe 5 is scanned by a fine adjusting mechanism 7 of X, Y, Z directions, then the reproduction is made while checking the current variation by a current amplifier circuit 15. At this time, the read-out information from a writing/reading circuit 10 is synchronized with a command timing signal of the circuit 9 and successively sent to a data preserving circuit 20 or 21 by the changeover of a switch 12 then compared by a comparator circuit 22. In this case, the same place on the medium 3 is scanned plural times, and the damage of probe is diagnosed by each data comparison processing. Thus, the reliability can be improved by means of judging in real time and issuing the command for error.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing method and an information processing apparatus that apply the principles of a scanning tunneling microscope.

0002

2. Description of the Related Art Various high-density recording methods have been known, and the representative ones are magnetic recording and optical recording. In magnetic recording, the recording length is determined by restrictions on devices such as magnetic heads used for recording and reproduction, and in this case, the limit is about 1 μm. In optical recording, the recording wavelength is limited by the beam diameter of the light used for recording and reproduction.
The limit is about 0.5 μm.

On the other hand, in recent years, a scanning tunneling microscope (hereinafter referred to as STM) has been developed [G. Binning e
tal. , Helvetica Physica A
cta, 55, 726 (1982)], the solid surface state can be measured with a horizontal resolution of several angstroms and a vertical resolution of
It is now possible to analyze with high resolution of angstroms or less.

[0004]Using this STM principle, recording and reproducing irregularities or changes in electronic state on the surface of a recording medium on the order of nanometers has been described, for example, in US Pat. , No. 161553.

[0005]

[Problem to be solved by the invention] However, STM
In a recording/reproducing device using a probe, the distance between the probe and the recording medium is close to each other, less than 1 nm, so the distance between the probe and the recording medium is controlled by strong impact, dust on the recording medium, or large structure of the substrate. For example, a response faster than the response frequency of electrical feedback sent to an actuator such as PZT or a displacement larger than the maximum displacement of the actuator may occur, making distance control impossible and causing the tip of the probe to touch the recording medium. may be damaged by contact with other objects, resulting in structural changes such as in multi-probes. If the recording/reproducing operation is continued with this damaged probe, there is a risk that the recorded information will be read in incorrectly and the information will be determined to be correct information.

An object of the present invention is to provide an information processing method and an information processing apparatus that can confirm whether the obtained information is correct information obtained with a normal probe.

[0007]

[Means for Solving the Problems] The present invention for achieving the above-mentioned object includes a method of moving a probe and a recording medium provided opposite to the probe relative to each other, and using the probe to record information on the recording medium. The information processing method for recording or reproducing information is characterized in that the probe reproduces the same location on the recording medium multiple times, and the obtained information from different times is compared and processed to confirm the state of the probe. It is an information processing method.

The present invention related to the above-mentioned specific invention provides an information processing apparatus that records or reproduces recorded information on a recording medium using the probe while relatively moving a probe and a recording medium provided opposite to the probe. , comprising a comparison means for reproducing the same part of the recording medium at least twice with the probe and comparing and determining information obtained at different times of reproduction, and confirming the state of the probe by comparison by the comparison means. This is an information processing device characterized by the following.

[0009]

[Operation] When reproducing information recorded on a recording medium, the information processing method and information processing apparatus having the above-described configuration scan the same location multiple times with a probe, and obtain the
The first scan information and the second and subsequent scan information are compared and reproduced.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail based on the illustrated embodiments. FIG. 1 is a configuration diagram of a recording/reproducing apparatus for explaining a first embodiment. A recording medium 3 formed on a substrate 1 and a base electrode 2 is placed on an XY direction coarse movement mechanism 4. A probe 5 is arranged above the recording medium 3, and the probe 5 is attached to a coarse movement mechanism 6 in the Z direction and a fine movement mechanism 7 in the XYZ directions. Reference numeral 8 denotes an interface for inputting and outputting write/read information, status information, control signals, address information, and error signals, and is connected to the control circuit 9, the write/read circuit 10, and the positioning circuit 11. The output of the control circuit 9 is the write/read circuit 10 and the positioning circuit 1.
1. Connected to switch 12. Further, the output of the write/read circuit 10 is supplied to a voltage application circuit 13 and a binarization processing circuit 14.
The voltage applying circuit 13 is connected to apply a pulsed voltage between the base electrode 2 and the probe 5 . The tunnel current flowing between the recording medium 3 and the probe 5 is amplified by a current amplification circuit 15, and is connected to a Z-direction drive circuit 17 and an XY-direction drive circuit 18 via a positioning circuit 11 and a servo circuit 16. The outputs of 17 and 18 are connected to the Z-direction coarse movement mechanism 6 and the XYZ-direction fine movement mechanism 7. In addition, the XY direction coarse movement mechanism 4 and the Z direction coarse movement mechanism 6
, the output of the XYZ direction fine movement mechanism 7 is connected to the positioning circuit 11 via a position detection circuit 19. Further, the output of the binarization processing circuit 14 is selectively connected to data storage circuits 20 and 21 by a switch 12, and these storage circuits 20 and 21 are selectively connected to each other.
, 21 are connected to the control circuit 9 via a comparison circuit 22.

[0011] The probe 5 is made of W, Pt, Pd, TiC, W.
It is manufactured from a conductive material such as C, and in this embodiment, Pd is deposited in a conical shape using a vacuum evaporation method. The recording medium 3 is a smooth substrate 1 obtained by cleaving mica (mica).
On a base electrode 2 on which gold (Au) is epitaxially grown, four layers of squarylium-bis-6-octylazulene having an electric memory effect are accumulated by the Langmuir-Prodgett method (LB method).

During operation, first, the probe 5 is separated from the recording medium 3 to avoid contact or collision with the recording medium 3, so the Z-direction coarse movement mechanism 6 and the XYZ-direction fine movement mechanism 7 bring the two closer together. The procedure is to apply a reading voltage of 1V between the probe 5 and the base electrode 2 of the recording medium 3 by the voltage application circuit 13, drive the Z-direction coarse movement mechanism 6 and the XYZ-direction fine movement mechanism 7, and amplify the current. probe 5 until the tunnel current detected by circuit 13 reaches 1 nA.
This is done by bringing the image closer to the recording medium 3. In this way, recording and reproduction can be performed by holding the coarse movement mechanism 6 in the Z direction and scanning the probe 5 over the recording medium 3 using the fine movement mechanism 7 in the XYZ directions.

When recording information, while scanning the recording area of the recording medium 3 with the probe 5, when the writing position is reached by a control signal from the control circuit 9, the voltage application circuit 13
This is performed by applying a pulse voltage with a pulse height of 3 V and a pulse width of 50 ns. This pulsed voltage is a voltage at which the recording medium 3 having an electric memory effect changes from an off (high resistance) state to an on (low resistance) state.

In the case of reproduction, while applying a voltage of 1V between the probe 5 and the base electrode 2 of the recording medium 3, the probe 5 is scanned over the recording area of the recording medium 3 using the XYZ direction fine movement mechanism 7. This is done by checking the current change in the current amplification circuit 15. Further, during this reproduction, probe damage diagnosis processing is also performed by comparing data.

In the comparison, the read information sent from the write/read circuit 10 is synchronized with the timing signal commanded from the control circuit 9, and is transferred to the data storage circuit 20 or 21 by switching the switch 12. The data are sequentially sent, the data are compared in the comparison circuit 22, the comparison circuit 22 determines whether the data is erroneous data or correct data, and a command is sent to the control circuit 9. Comparison information includes one-dimensional, two-dimensional, and three-dimensional information comparison, and in comparison of one-dimensional information, the same recorded location on the recording medium 3 is scanned multiple times with the probe 5 to obtain information. Compare round-trip data. FIG. 2 shows a schematic cross-sectional view of the scanning state of the probe 5 with respect to recorded data during reproduction, and D is recorded data on the recording medium 3 recorded by this recording method.

Further, FIG. 3 is a graph of the first scan information obtained from FIG. 2, and FIG. 4 is a graph of the second scan information. These Figures 3 and 4 are
The information sent from the write/read circuit 10 and processed by the binarization processing circuit 14 is expressed as a linear function of the position X, and this information corresponds to the outputs of the data storage circuits 20 and 21 in FIG.

Comparing FIGS. 3 and 4, the recorded data D written in FIG. 2 is 1 data, whereas in FIG. 4 it is 2 data. This can be presumed to be because the tip of the probe 5 was damaged by a strong impact from the outside, resulting in a structural change, such as in a multi-probe, as shown in FIG.

These comparisons are made in a comparison circuit 22. Here, since the data obtained in the first and second scans are not the same, the control circuit 9 determines that the probe 5 is damaged and sends an error signal to the host model through the interface 8 to confirm that the probe is damaged. You can know in real time.

Next, a comparative example of two-dimensional information will be explained.
6 and 7 show the output information of the binarization processing circuit 14 at the position (X
, Y) as a quadratic function. FIG. 6 is the first scan information, and FIG. 7 is the second scan information. This result also indicates that the probe 5 was damaged and its tip became a multi-probe. The comparison result is
When there is little information, it is the same as comparing one-dimensional information, but when multiple pieces of information exist randomly, the information is compared with two-dimensional information.
It is necessary to compare two-dimensional information captured as value image information.

In each of the above-described embodiments, when information is reproduced, by scanning the same location multiple times, it is possible to reproduce the information while constantly comparing and processing the information, and when the probe comes into contact with the medium during reproduction, Since a probe damage signal indicating that the probe has been damaged is sent, it is determined within the device through signal processing that the probe is no longer functioning properly in real time.

[0021] During these multiple scans, the data of the one-dimensional recorded information is often data obtained from multiple scans in the same direction, or reciprocating data, i.e., a comparison of data obtained from each reciprocating scan. It can also be processed.

[0022] Similar comparisons can also be made in the case of three-dimensional information, and furthermore, in the case of data comparison of two-dimensional and three-dimensional information, if the data is the same, the first data and the second data can be compared. The scanning direction, scanning start point, and scanning end point of the data do not necessarily have to match.

Furthermore, for example, the probe or the recording medium may be rotated by a predetermined angle after the first scan using a rotation mechanism (not shown) to perform the next scan.

[0024]

Effects of the Invention As explained above, the information processing method and information processing apparatus according to the present invention are capable of determining in real time that the tip of the probe has been damaged during recording and reproducing operations and sending an error command. possible and has high reliability.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of a recording/reproducing apparatus according to the present invention.

FIG. 2 is a schematic cross-sectional view of a scanning situation.

FIG. 3 is a graph diagram of the first scan result for one-dimensional information.

FIG. 4 is a graph of the second scan results.

FIG. 5 is a schematic cross-sectional view of a scanning situation.

FIG. 6 is a graph diagram of a first scan result for two-dimensional information.

FIG. 7 is a graph of the second scan results.

[Explanation of symbols]

2 Base electrode 3 Recording medium 4 XY coarse movement mechanism 5 Probe 6 Z direction coarse movement mechanism 7 XYZ direction fine movement mechanism 8 Interface 9 Control circuit 10 Write/read circuit 11 Positioning circuit 12 Switch 13 Voltage application circuit 14 Binarization processing circuit 15 Current amplification circuit 17 Z direction drive circuit 18 XY direction drive circuit 19 Position detection circuit 20, 21 Data storage circuit 22 Comparison circuit

Claims (5)

[Claims] 1. An information processing method for recording or reproducing recorded information on a recording medium using the probe while relatively moving a probe and a recording medium provided opposite to the probe, wherein the probe records or reproduces recorded information on the recording medium. An information processing method comprising: reproducing the same part a plurality of times, comparing and processing the information obtained at different times, and confirming the state of the probe. 2. The information processing method according to claim 1, wherein the obtained information is one-dimensional information. 3. The information processing method according to claim 1, wherein the obtained information is two-dimensional information. 4. The information processing method according to claim 1, wherein the obtained information is three-dimensional information. 5. An information processing apparatus that records or reproduces recorded information on the recording medium using the probe while relatively moving a probe and a recording medium provided facing the probe, wherein the probe records or reproduces recorded information on the recording medium. An information processing device characterized in that the information processing device is characterized in that it is equipped with a comparing means for reproducing the same part at least twice and comparing and determining the information obtained at different times of reproduction, and confirming the state of the probe by the comparison by the comparing means. .