JP6628168B2 - Information recording medium - Google Patents

Description

  The present invention relates to a technology for writing and storing information on a durable information recording medium, and in particular, a technology for recording information as a fine physical structure pattern by performing beam exposure and patterning on a substrate. About.

  Paper has been used for a long time as a medium for recording various information, and even today, much information is recorded on paper. On the other hand, with the development of industry, films for recording image information and record boards for recording sound information have been used. In recent years, with the spread of computers, media for recording digital data have been used. For example, magnetic recording media, optical recording media, semiconductor recording media, and the like have been used.

  The above-described information recording medium has a durability that does not hinder use depending on its use. For example, an information recording medium such as a paper print, a film, and a record board can be said to be a medium having sufficient durability on a time scale of several years. However, when viewed on a time scale of several decades, deterioration due to aging is inevitable, and the recorded information may be lost. In addition, there is a possibility of damage due to the action of water and heat as well as aging.

  In addition, magnetic recording media for computers, optical recording media, semiconductor recording media, and the like have durability that does not hinder the use of general electronic devices, but they have a time scale of several tens of years in the first place. It is not designed for permanent information storage because it has not been designed in consideration of its durability.

  On the other hand, Patent Literature 1 below discloses a method of recording information on a durable medium such as quartz glass while increasing the recording capacity. There is disclosed a method in which data is recorded in advance, and information is read out by using computer tomography technology while rotating the medium. Patent Document 2 discloses that in order to achieve the same object, a cylindrical recording medium is irradiated with an electromagnetic wave while changing an irradiation angle to measure a difference in transmittance. A method of reading information by utilizing the method is disclosed.

  Note that plate-shaped information recording media are classified into front and back, top and bottom, and right and left. There is a need to do. Therefore, a method has been proposed in which an identification mark indicating a direction for performing a correct reading process is provided on a medium. For example, in Patent Document 3 below, an identification mark having an uneven structure is provided in the lower right corner on the front side of a card-shaped information recording medium, so that even a visually impaired person can recognize the direction of the medium by touch. There has been disclosed a technique for enabling a card-shaped information recording medium to be inserted in an information reading device in a correct direction.

Japanese Patent No. 4991487 Japanese Patent No. 5286246 JP-A-9-269987

  As described above, information recording media that are currently generally used are designed in consideration of durability for several years to several tens of years, and therefore, have a long time scale of several hundred years to several thousand years. It is inappropriate for leaving information for future generations. For example, physically or chemically fragile information recording media such as paper, film, and record discs cannot be expected to have durability for a long period of several hundred to several thousand years. Of course, information recording media for computers, such as magnetic recording media, optical recording media, and semiconductor recording media, are also unsuitable for such uses.

  In human history, stone monuments exist as information recording media with a time scale of hundreds to thousands of years, but it is very difficult to record information with high integration on a stone slab. A stone bed is not suitable as a medium for recording a large amount of information such as digital data.

  On the other hand, if a method of three-dimensionally recording information inside a cylindrical quartz glass as a medium as in the techniques disclosed in the above-mentioned Patent Documents 1 and 2 is adopted, a considerably long-term durability can be obtained. An information recording method capable of achieving high integration while maintaining performance can be realized. However, at the time of reading, since it is necessary to extract information from cells three-dimensionally dispersed in the medium, it is necessary to perform Fourier transform processing or the like using the technique of computer tomography. In other words, even after a long time scale of hundreds to thousands of years, information cannot be read unless the same technique of computer tomography as in recording is inherited.

  Therefore, the inventor of the present application can record information with a high degree of integration while maintaining long-term durability in Japanese Patent Application No. 2014-059542 (hereinafter, referred to as a prior application), and furthermore, using a universal method. An information storage method and apparatus capable of reading information has been proposed, and a method and apparatus for reading original information from a medium in which information has been stored in such a method has been proposed. Hereinafter, the content of the proposal in the earlier application is referred to as the earlier application invention.

  In the invention of the prior application, the digital data to be stored is expressed as a graphic pattern, and is transferred onto a substrate by beam exposure using an electron beam or a laser beam. Then, by performing a patterning process on the substrate, data is recorded as a fine physical structure pattern. Therefore, information can be recorded with a high degree of integration while maintaining long-term durability. Moreover, since the graphic pattern transferred onto the substrate is itself a two-dimensional pattern, information can be read out by a universal method.

  However, even when beam exposure and patterning are performed using the same figure pattern, the physical structure actually formed on the substrate differs depending on the beam exposure and patterning method employed. For example, when a bit “0” and a bit “1” are separately recorded as a concavo-convex structure formed on a substrate, a convex portion becomes a bit “1” depending on a method of a beam exposure and patterning process to be adopted. The concave portion becomes a bit “1”.

  Specifically, at the time of beam exposure, the result of recording on the medium differs depending on whether the area indicating bit “0” is exposed or the area indicating bit “1” is exposed. Similarly, the result of recording on the medium varies depending on the patterning conditions such as whether a positive resist or a negative resist is used as the resist layer formed on the substrate. Therefore, with only the information of the data bits recorded on the information recording medium, the convex portion should be interpreted as bit "1" and read out, or the concave portion should be interpreted as bit "1" and read out. I can't tell what it is.

  Therefore, the present invention, by performing beam exposure and patterning processing on the substrate, when recording information as a fine physical structure pattern, it is also possible to record information indicating the data bit interpretation method together An object is to provide an information recording medium.

(1) A first aspect of the present invention is an information storage device for writing and storing digital data on an information recording medium,
A data input unit for inputting digital data to be stored;
A main information pattern generation unit that generates a main information pattern indicating information of individual data bits constituting the digital data;
A sub-information pattern generating unit that generates a sub-information pattern indicating a method of interpreting the data bits indicated by the main information pattern;
A drawing data generation unit that generates drawing data for drawing the main information pattern and the sub information pattern,
A beam exposure apparatus that performs beam exposure using an electron beam or a laser beam on a substrate serving as an information recording medium based on the drawing data,
By performing a patterning process on the substrate that has been exposed, a patterning apparatus that generates an information recording medium on which a physical structure pattern is formed in accordance with drawing data,
And
The main information pattern is composed of a first attribute main area and a second attribute main area, and a predetermined point corresponding to each data bit exists in the first attribute main area, or the second attribute main area. Depending on the presence or absence in the area, the binary information of each data bit is represented as a pattern,
The sub-information pattern includes a first identification mark having one or a plurality of closed areas for presenting first information including characters, numbers, symbols, graphics, or a part thereof, or a combination thereof; And a second identification mark having one or more closed regions for presenting second information composed of letters, numbers, symbols, figures, or a part thereof, or a combination thereof. So that
In the closed area forming the first identification mark, a band-shaped first attribute sub-area and a band-shaped second attribute sub-area extending in a direction parallel to the predetermined arrangement axis Z are orthogonal to the arrangement axis Z. In the closed region constituting the second identification mark, a band-shaped first attribute sub-region and a band-shaped second attribute sub-region extending in a direction parallel to the arrangement axis Z are arranged alternately in the direction. For a closed area that is alternately arranged in a direction orthogonal to the arrangement axis Z and that constitutes the first identification mark, the width of the first attribute sub-area is greater than the width of the second attribute sub-area. The width of the second attribute sub-region is set to be wider than the width of the first attribute sub-region for a closed region that is set to be wider and forms the second identification mark,
The drawing data generation unit performs drawing for exposing the first attribute main region and the first attribute sub-region, and not performing exposure for the second attribute main region and the second attribute sub-region. Data or drawing data for exposing the second attribute main region and the second attribute sub-region and exposing the first attribute main region and the first attribute sub-region is not stored. The width of the first attribute sub-region and the width of the first attribute sub-region are set to dimensions that can form a diffraction grating for visible light.

(2) According to a second aspect of the present invention, in the information storage device according to the first aspect,
The sub-information pattern generation unit is configured to generate a sub-information pattern in which the first identification mark and the second identification mark formed on the information recording medium have a size that can be visually observed.

(3) A third aspect of the present invention provides the information storage device according to the first or second aspect described above,
The sub-information pattern generation unit sets the width of the first attribute sub-region to be at least five times the width of the second attribute sub-region for the closed region forming the first identification mark, and performs the second identification. The closed area forming the mark is set such that the width of the second attribute sub-area is at least five times the width of the first attribute sub-area.

(4) According to a fourth aspect of the present invention, in the information storage device according to the above-described first to third aspects,
The sub-information pattern generation unit sets the width of the first attribute sub-region in the closed region constituting the first identification mark equal to the width of the second attribute sub-region in the closed region constituting the second identification mark. The width of the second attribute sub-region in the closed region forming the first identification mark is set to be equal to the width of the first attribute sub-region in the closed region forming the second identification mark. It is.

(5) The fifth aspect of the present invention is the information storage device according to the above-described first to fourth aspects,
The sub-information pattern generation unit is configured to generate a sub-information pattern in which a first identification mark and a second identification mark are arranged adjacent to each other.

(6) A sixth aspect of the present invention provides the information storage device according to the first to fourth aspects described above,
The sub-information pattern generation unit is configured to generate a sub-information pattern in which a closed area forming the first identification mark and a closed area forming the second identification mark are in contact with each other.

(7) According to a seventh aspect of the present invention, in the information storage device according to the above-described first to fourth aspects,
A sub-information pattern generation unit generates a sub-information pattern in which a second identification mark is embedded inside a first identification mark or a sub-information pattern in which a first identification mark is embedded inside a second identification mark. It is intended to be.

(8) An eighth aspect of the present invention is the information storage device according to the first to fourth aspects described above,
A sub-information pattern generation unit that generates a sub-information pattern having an auxiliary common identification mark in addition to the first identification mark and the second identification mark;
The auxiliary common identification mark is an identification mark having one or a plurality of closed areas for presenting auxiliary common information including characters, numbers, symbols, graphics, or a part thereof, or a combination thereof,
In the closed area constituting the auxiliary common identification mark, a band-shaped first attribute sub-area and a band-shaped second attribute sub-area extending in a direction parallel to the arrangement axis Z alternately in a direction orthogonal to the arrangement axis Z. And the difference between the width of the first attribute sub-region in the auxiliary common identification mark and the width of the second attribute sub-region is the first attribute sub-region in the first identification mark and the second identification mark. The difference is set to be smaller than the difference between the width of the region and the width of the second attribute sub-region.

(9) A ninth aspect of the present invention is the information storage device according to the eighth aspect described above,
The width of the first attribute sub-region and the width of the second attribute sub-region in the auxiliary common identification mark are set to be equal.

(10) The tenth aspect of the present invention is the information storage device according to the eighth or ninth aspect,
The combination of the first identification mark and the auxiliary common identification mark constitutes a mark indicating the first interpretation method of the data bit indicated by the main information pattern, and the mark of the second identification mark and the auxiliary common identification mark is formed. A mark indicating a second interpretation method of the data bit indicated by the main information pattern is configured by the combination.

(11) An eleventh aspect of the present invention is the information storage device according to the tenth aspect described above,
Three rectangles, a left rectangle, a center rectangle, and a right rectangle, are arranged adjacent to each other in the horizontal direction such that they are left, center, and right, respectively, and a lower rectangle is common below and adjacent to these three rectangles. And place
By forming the first identification mark by the center rectangle, configuring the second identification mark by the left rectangle and the right rectangle, and configuring the auxiliary common identification mark by the lower rectangle, the first mark indicating the character “convex” is formed. A chapter and a second mark indicating the character "concave" are configured.

(12) A twelfth aspect of the present invention is the information storage device according to the first to eleventh aspects,
Beam exposure apparatus has a function of performing beam exposure on the surface of the resist layer, for a substrate having a layer to be molded and a resist layer covering the same,
A patterning device is used to impregnate the substrate with a developing solution having a property of dissolving the exposed or unexposed portions of the resist layer, and perform a process of processing a part of the substrate as a remaining portion, and a remaining portion of the resist layer. And an etching processing section for performing etching on the layer to be molded as a mask.

(13) A thirteenth aspect of the present invention provides the information storage device according to the twelfth aspect,
The main information pattern generation unit converts one of the individual bits “1” and the individual bits “0” into an individual bit graphic composed of a closed area, and converts the area inside the bit graphic into the first bit graphic. Generating a main information pattern having an attribute main area and an external area as a second attribute main area;
A drawing data generation unit that performs exposure on the first attribute main area and the first attribute sub area and does not perform exposure on the second attribute main area and the second attribute sub area; It is designed to generate data.

(14) A fourteenth aspect of the present invention is the information storage device according to the first to thirteenth aspects,
The patterning device is configured to form a physical structure having a concavo-convex structure including a concave portion indicating one of a first attribute region and a second attribute region and a convex portion indicating the other.

(15) A fifteenth aspect of the present invention is the information storage device according to the fourteenth aspect,
The patterning device forms a physical structure having an additional layer made of a light-reflective material on the surface of the projection.

(16) A sixteenth aspect of the present invention is the information storage device according to the fourteenth aspect,
A patterning device forms a concave-convex structure on the upper surface by performing a patterning process on a substrate made of a light-transmitting material, and forms a physical structure having an additional layer made of a light-shielding material on the lower surface of the substrate. It was made.

(17) A seventeenth aspect of the present invention is the information storage device according to the fourteenth aspect,
A patterning device forms a concavo-convex structure by performing a patterning process on a substrate made of a light-transmitting material, and forms a physical structure having an additional layer made of a light-shielding material on the surface of the projection. It was done.

(18) An eighteenth aspect of the present invention is the information storage device according to the first to thirteenth aspects,
The patterning device is configured to form a physical structure having a network structure including a through hole indicating one of a first attribute region and a second attribute region and a non-hole portion indicating the other. .

(19) A nineteenth aspect of the present invention is the information storage device according to the eighteenth aspect,
A patterning apparatus forms a physical structure having an additional layer made of a light-reflective material on one surface of a non-hole portion.

(20) The twentieth aspect of the present invention is the information storage device according to the eighteenth aspect,
A patterning apparatus forms a net-like structure by performing a patterning process on a substrate made of a light-transmitting material, and forms a physical structure having an additional layer made of a light-shielding material on one surface of a non-hole portion. It was made.

(21) According to a twenty-first aspect of the present invention, in the information storage device according to the first to eleventh aspects,
The data input unit, the main information pattern generation unit, the sub information pattern generation unit, and the drawing data generation unit are configured by incorporating a program into a computer.

  (22) In a twenty-second aspect of the present invention, a computer is used as the data input unit, the main information pattern generation unit, the sub-information pattern generation unit, and the drawing data generation unit in the information storage device according to the first to eleventh aspects described above. It is a program that works.

(23) A twenty-third aspect of the present invention relates to an information storage method for writing and storing digital data on an information recording medium,
A data input step in which the computer inputs digital data to be stored;
A main information pattern generation step in which the computer generates a main information pattern indicating information of individual data bits constituting digital data;
A computer for generating a sub-information pattern indicating a method of interpreting the data bits indicated by the main information pattern;
A computer, a drawing data generating step of generating drawing data for drawing the main information pattern and the sub information pattern,
Based on the drawing data, on a substrate serving as an information recording medium, a beam exposure step of performing beam exposure using an electron beam or laser light,
By performing a patterning process on the exposed substrate, a patterning step of generating an information recording medium on which a physical structure pattern according to the drawing data is formed,
To do
The main information pattern is composed of a first attribute main area and a second attribute main area, and a predetermined point corresponding to each data bit exists in the first attribute main area, or the second attribute main area. It is a pattern in which the binary information of each data bit is expressed depending on whether it exists in the area or not,
The sub-information pattern includes a first identification mark having one or a plurality of closed areas for presenting first information including characters, numbers, symbols, graphics, or a part thereof, or a combination thereof; And a second identification mark having one or more closed regions for presenting second information composed of characters, numbers, symbols, graphics, or a part thereof, or a combination thereof. So that
In the closed area forming the first identification mark, a band-shaped first attribute sub-area and a band-shaped second attribute sub-area extending in a direction parallel to the predetermined arrangement axis Z are orthogonal to the arrangement axis Z. In the closed region constituting the second identification mark, a band-shaped first attribute sub-region and a band-shaped second attribute sub-region extending in a direction parallel to the arrangement axis Z are arranged alternately in the direction. For a closed area that is alternately arranged in a direction orthogonal to the arrangement axis Z and that constitutes the first identification mark, the width of the first attribute sub-area is greater than the width of the second attribute sub-area. The width of the second attribute sub-region is set to be wider than the width of the first attribute sub-region for the closed region constituting the second identification mark.
In the drawing data generation step, the first attribute main area and the first attribute sub area are exposed, and the second attribute main area and the second attribute sub area are not exposed. Data or drawing data for exposing the second attribute main region and the second attribute sub-region and exposing the first attribute main region and the first attribute sub-region is not stored. The width of the generated first attribute sub-region and the width of the second attribute sub-region is set so that the diffraction grating for visible light can be formed.

  According to the present invention, information of individual data bits constituting digital data to be stored is recorded as a main information pattern on a medium, and further indicates a method of interpreting the data bits indicated by the main information pattern. Information is recorded as a sub-information pattern on the same medium. Here, each information pattern is composed of a first attribute area and a second attribute area. For example, information is recorded on a substrate such that one attribute area is a convex part and the other attribute area is a concave part. Done. The sub-information pattern includes a pair of identification marks, and a diffraction grating in which band-like first attribute regions and band-like second attribute regions are alternately arranged is formed in each identification mark. .

  In addition, the magnitude relationship between the width of the band-shaped first attribute region formed in each identification mark and the width of the band-shaped second attribute region is reversed with respect to the pair of identification marks. Therefore, irrespective of the beam exposure and patterning method employed at the time of information recording, it is possible to recognize the correct interpretation method of the data bits recorded as the main information pattern by comparing the brightness of the pair of identification marks. it can.

  As described above, according to the present invention, when information is recorded as a fine physical structure pattern by performing beam exposure and patterning processing on a substrate, information indicating a data bit interpretation method is also recorded. It becomes possible to do.

1 is a block diagram illustrating a basic configuration of an information storage device that can use the present invention. FIG. 2 is a schematic diagram illustrating an example of a specific information storage process by the information storage device illustrated in FIG. 1. FIG. 3 is an enlarged view of a unit recording graphic pattern R (U1) shown in FIG. 2. FIG. 2 is a side sectional view showing a specific process (a process using a positive resist as a resist layer 20) of an exposure step by a beam exposure apparatus 200 and a patterning step by a patterning apparatus 300 shown in FIG. Illustration of the inner structure is omitted). FIG. 2 is a side sectional view showing a variation of the information recording medium on which information has been written by the information storage device shown in FIG. 1 (only the cut surface is shown, and the inner structure is not shown). FIG. 2 is a block diagram showing a basic configuration of an information reading device for reading information from an information recording medium created by the information storage device shown in FIG. 1. FIG. 2 is a plan view showing a variation of an alignment mark used in the information storage device shown in FIG. FIG. 2 is a plan view showing a variation of an arrangement form of an alignment mark used in the information storage device shown in FIG. 1. FIG. 2 is a plan view showing another variation of the alignment mark used in the information storage device shown in FIG. FIG. 3 is a plan view showing another variation of the arrangement of the alignment marks used in the information storage device shown in FIG. 1. 2 is a flowchart showing a basic processing procedure of information storage processing executed by the information storage device shown in FIG. 1. 7 is a flowchart showing a basic processing procedure of information reading processing executed by the information reading device shown in FIG. 6. FIG. 4 is a side sectional view showing a general duplication method of an information recording medium having an uneven structure on a surface. FIG. 14 is a side sectional view showing a state in which a duplicate is created by the duplication method shown in FIG. 13. FIG. 9 is a plan view showing the relationship between an original M1 and a copy M2 of the original M1 when a method of recording a large “F” as an identification mark is used (hatching is for indicating an area). FIG. 5 is a side cross-sectional view showing another specific process (a process using a negative resist as the resist layer 20) different from the exposure step and the patterning step shown in FIG. 4 (only the cut surface is shown, and the inner structure is shown) Is omitted). FIG. 17 is a plan view showing a relationship between an original M3 created by the process shown in FIG. 16 and a copy M4 thereof (hatching is for indicating an area). 1 is a block diagram illustrating a basic configuration of an information storage device according to a basic embodiment of the present invention. FIG. 19 is a plan view showing an information recording medium M5 created by executing the process shown in FIG. 4 by the information storage device shown in FIG. 18 (hatching is for indicating an area). FIG. 19 is a plan view showing an information recording medium M6 created by executing the process shown in FIG. 16 by the information storage device shown in FIG. 18 (hatching is for indicating an area). 19 is a plan view showing an example of a drawing pattern P (E) created by the information storage device shown in FIG. FIG. 22 is a diagram illustrating an uneven structure of a medium M5 (“black concave medium” illustrated in FIG. 19) created by performing the process illustrated in FIG. 4 based on the drawing pattern P (E) illustrated in FIG. FIG. 22 is a diagram illustrating an uneven structure of a medium M6 (“black convex medium” illustrated in FIG. 20) created by executing the process illustrated in FIG. 16 based on the drawing pattern P (E) illustrated in FIG. FIG. 23 is an enlarged side sectional view of each uneven structure shown in the lower part of FIG. FIG. 24 is an enlarged side sectional view of each concave-convex structure shown in the lower part of FIG. 23. FIG. 2 is a plan view showing a basic example of the configuration and arrangement of identification marks used in the present invention. It is a top view which shows the modification of a structure and arrangement | positioning form of the identification mark used for this invention. It is a top view which shows another modification of the structure and arrangement | positioning form of the identification mark used for this invention. FIG. 29 is a plan view of a drawing pattern P (E) having an identification mark according to a modification shown in FIG. 28 (b). It is a top view showing a modification using an auxiliary common identification mark in addition to a 1st identification mark and a 2nd identification mark. FIG. 31 is a plan view showing an observation mode of each identification mark in the modification example shown in FIG. 30 (hatching is for indicating an area). FIG. 19 is a sectional side view showing a first variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only a cut surface is shown, and an inner structure is not shown). FIG. 19 is a side cross-sectional view showing a second variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only the cut surface is shown, and the inner structure is not shown). FIG. 19 is a sectional side view showing a third variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only the cut surface is shown, and the inner structure is not shown). FIG. 19 is a sectional side view showing a fourth variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only a cut surface is shown, and an inner structure is not shown). FIG. 19 is a side sectional view showing a fifth variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only the cut surface is shown, and the inner structure is not shown). FIG. 19 is a side sectional view showing a sixth variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only the cut surface is shown, and the inner structure is not shown). FIG. 19 is a side sectional view showing a seventh variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only the cut surface is shown, and the inner structure is not shown). FIG. 19 is a side sectional view showing an eighth variation of the information recording medium on which information has been written by the information storage device shown in FIG. 18 (only the cut surface is shown, and the inner structure is not shown). 19 is a flowchart showing a basic processing procedure of an information storage process executed by the information storage device shown in FIG. 18.

  Hereinafter, the present invention will be described based on an illustrated embodiment. As described above, the present invention presupposes a technique of recording information as a fine physical structure pattern by performing beam exposure and patterning processing on a substrate. One example of such a technique is described above. The invention is described in Japanese Patent Application No. 2014-059542. Since the content of the prior invention is not disclosed at the time of filing the present application, the prior invention will be described in §1 to §5 for convenience of explanation. The contents of §1 to §5 below and the contents of FIGS. 1 to 12 are the same as the contents of §1 to §5 of FIGS. Substantially the same.

<<<< §1. Basic embodiment of information storage device according to prior invention >>>>>
FIG. 1 is a block diagram showing a configuration of a basic embodiment of an information storage device according to the invention of the prior application. The information storage device according to this embodiment is a device that performs a function of writing and storing digital data on an information recording medium, and includes a storage processing computer 100, a beam exposure device 200, and a patterning device 300 as illustrated. .

  Here, the storage processing computer 100 executes a process of creating the drawing data E based on the digital data D to be stored. The beam exposure apparatus 200 is an apparatus that performs a beam exposure using an electron beam or a laser beam on a substrate S serving as an information recording medium based on the drawing data E. A drawing pattern is formed. The patterning device 300 forms a physical structure pattern according to the drawing data E by performing a patterning process on the exposed substrate S, and creates the information recording medium M. As a result, information corresponding to the digital data D is recorded on the information recording medium M as a physical structure pattern.

  As illustrated, the storage processing computer 100 includes a data input unit 110, a unit data generation unit 120, a unit bit matrix generation unit 130, a unit bit graphic pattern generation unit 140, a unit recording graphic pattern generation unit 150, a drawing data generation unit 160. Hereinafter, the functions of these units will be described in order. However, these units are actually realized by incorporating a dedicated program into a computer, and the storage processing computer 100 may be configured by installing a dedicated program into a general-purpose computer. it can.

  First, the data input unit 110 is a component having a function of inputting digital data D to be stored, and also has a function of temporarily storing the input digital data D. The digital data D to be stored may be in any form, such as document data, image data, and audio data.

  The unit data generation unit 120 is a component that generates a plurality of unit data by dividing the digital data D input by the data input unit 110 in units of a predetermined bit length. Here, for convenience of explanation, as shown in the upper part of FIG. 2, the following description will be made with an example where four sets of unit data are generated by dividing digital data D in units of bit length u. And the i-th unit data is indicated by a symbol Ui (in this example, i = 1 to 4). The terms bearing the phrase "unit" used in the following description indicate that each term is created for "one unit data".

  The bit lengths of the individual unit data Ui need not necessarily be equal, and a plurality of unit data having different bit lengths may be generated. However, in practice, it is preferable that the bit recording area Ab described later be an area having the same shape and the same area. For this purpose, a common bit length u is determined in advance, and all the unit data Ui have the same bit length u. It is preferable that the data has

  The common bit length u can be set to an arbitrary value. However, in practice, u = m × n is set so that a unit bit matrix of m rows and n columns can be formed. The generation unit 120 may divide the digital data into unit data composed of (m × n) bits. Here, for convenience of explanation, an example is shown in which u is set to 25 bits so that a unit bit matrix of 5 rows and 5 columns can be formed by setting m = n = 5. The value is preferably set to a larger value.) The first unit data U1 shown in FIG. 2 is unit data generated based on such settings, and is composed of 25-bit data.

  The unit data generation unit 120 may divide the input digital data D by dividing the input digital data D into u bits at a time, for example, and divide them into unit data U1, U2, U3,. In this case, unless the entire length of the digital data D is an integral multiple of the bit length u, the length of the last unit data is less than the bit length u. Therefore, when it is desired to make the lengths of all the unit data equal to the common bit length u, dummy bits are added to the end of the digital data D so that the entire length becomes an integral multiple of the bit length u. Adjust it.

  Note that the method of dividing the digital data D is not necessarily limited to a method of dividing the digital data D by a predetermined bit length u from the beginning. For example, when dividing into four, the first, fifth, ninth,. Are extracted as the first unit data U1, the second, sixth, tenth,..., And the second bit are extracted as the second unit data U2, and the third, seventh, eleventh,. .., And the fourth bit is extracted as the fourth unit data U4. It is also possible to take.

  The individual unit data Ui generated by the unit data generator 120 is provided to the unit bit matrix generator 130. The unit bit matrix generation unit 130 performs a process of generating a unit bit matrix B (Ui) by arranging the data bits constituting each unit data Ui in a two-dimensional matrix of m rows and n columns.

  In FIG. 2, the 25-bit data constituting the first unit data U1 is divided into five bits from the beginning, and is divided into "11101", "10110", "01001", "11001", and "10110". An example is shown in which groups are formed, and a unit bit matrix B (U1) composed of a matrix of 5 rows and 5 columns in which individual groups are arranged in one row is shown. Of course, the unit bit matrices B (U2), B (U3) and B (U4) are generated for the unit data U2, U3 and U4 in the same manner.

  The individual unit bit matrices B (Ui) thus generated by the unit bit matrix generation unit 130 are provided to the unit bit graphic pattern generation unit 140. The unit bit figure pattern generation unit 140 converts each unit bit matrix B (Ui) into a geometric pattern arranged in a predetermined bit recording area on a two-dimensional plane, thereby obtaining a unit bit figure pattern. A process for generating P (Ui) is performed.

  The middle part of FIG. 2 shows an example of a unit bit graphic pattern P (U1) created based on a unit bit matrix B (U1) composed of a matrix of 5 rows and 5 columns. In the case of this example, a square bit recording area Ab (area indicated by a broken line in the figure) is defined on a two-dimensional plane, and small square dots (hereinafter, referred to as bit figures) filled in black are arranged therein. Thus, a unit bit figure pattern P (U1) is formed.

  Here, each bit figure corresponds to the bit “1” constituting the unit bit matrix B (U1). In other words, within the bit recording area Ab, a matrix of 5 rows and 5 columns is defined corresponding to the unit bit matrix B (U1), and corresponds to the bit “1” in the unit bit matrix B (U1). The bit graphic is arranged only at the position, and nothing is arranged at the position corresponding to the bit “0”. Therefore, this unit bit figure pattern P (U1) expresses 25 bits of information forming the unit bit matrix B (U1) depending on the presence / absence of a bit figure at each position forming the matrix of 5 rows and 5 columns. Will be.

  Of course, each bit figure may be arranged corresponding to the bit “0” constituting the unit bit matrix B (U1). In this case, the bit figure is arranged only at the position corresponding to bit "0" in the unit bit matrix B (U1), and nothing is arranged at the position corresponding to bit "1". In short, the unit bit graphic pattern generation unit 140 converts one of the individual bits “1” and the individual bits “0” forming the unit bit matrix B (U1) into the individual bit graphic May be performed. In addition, the format of the data indicating each bit figure may be any format. For example, if one bit graphic is configured by a rectangle, the coordinate values of four vertices of each bit graphic (or the coordinate values of two diagonal vertices may be used) as the data indicating the unit bit graphic pattern P (U1). Data indicating the coordinate value of the center point (or the lower left corner point or the like) of each bit figure and data indicating the length of the vertical and horizontal sides of the bit figure having a common rectangular shape. Can also be used. Alternatively, when a circular bit figure is employed, data indicating the coordinate value of the center point of each bit figure and data indicating a common radius value can be used.

  Of course, the unit bit matrices B (U2), B (U3), B (U4) generated for the unit data U2, U3, U4 are also converted into geometric patterns by the same method, and the unit bit graphic pattern P (U2), P (U3) and P (U4) are generated. If the unit bit graphic patterns P (U1) to P (U4) thus generated are formed on a medium by any method, the information of the digital data D can be recorded on the medium. However, in the invention of the prior application, an alignment mark is added to each of the unit bit graphic patterns P (U1) to P (U4) in consideration of the convenience of the reading process performed later.

  The unit recording graphic pattern generation unit 150 is a component for adding the alignment mark. In this application, the unit recording graphic pattern P (Ui) with the alignment mark added thereto is converted into a unit recording graphic pattern. This is called a pattern R (Ui). As a result, the unit recording graphic pattern generation unit 150 adds the alignment mark to the unit bit graphic pattern P (Ui) generated by the unit bit graphic pattern generation unit 140, and generates the unit recording graphic pattern R (Ui). Processing will be performed.

  The middle part of FIG. 2 shows an example in which a cross-shaped alignment mark Q is added to the four outer corners of the unit bit graphic pattern P (U1) to generate a unit recording graphic pattern R (U1). Here, an area including the bit recording area Ab (dashed square) in which the unit bit figure pattern P (U1) is formed and the alignment marks Q arranged at the four outer corners is defined as the unit recording area Au ( (Dotted line square). The unit recording graphic pattern R (U1) is a graphic pattern formed in the unit recording area Au.

  The alignment mark Q is used for recognizing each bit recording area Ab in the reading process described in §3. Therefore, the alignment mark Q is arranged at a specific position with respect to the bit recording region Ab (in the illustrated example, at the four outer corners of the bit recording region Ab). In the illustrated example, an example using a cross-shaped alignment mark Q is shown. However, a figure that can be distinguished from a bit figure (in the illustrated example, a small black solid square) representing each bit. In this case, any shape may be used.

  In the illustrated example, the alignment mark Q is arranged outside the bit recording area Ab. However, the alignment mark Q can be arranged inside the bit recording area Ab. However, in the case where the alignment mark is arranged inside the bit recording area Ab, there is a possibility of interfering with the bit figure representing each bit. Therefore, in practice, as shown in the illustrated example, the alignment mark is located outside the bit recording area Ab. It is preferable to arrange Q. Variations in the shape and arrangement of the alignment mark Q will be described again in §4.

  When the unit recording graphic pattern generation unit 150 generates four sets of unit recording graphic patterns R (U1) to R (U4) in this manner, the drawing data generation unit 160 generates drawing data E for drawing these. Perform generation processing. Specifically, the drawing data generation unit 160 arranges four sets of unit recording areas R (U1) to R (U4) in a two-dimensional matrix as shown in the lower part of FIG. In the case of this example, a drawing pattern P (E) including all four sets of unit recording graphic patterns R (U1) to R (U4) is generated, and the drawing pattern P (E ) Is performed to generate drawing data E for drawing.

  The processing functions of the individual components of the storage processing computer 100 shown in FIG. 1 have been described above. The drawing data E thus generated is given to the beam exposure apparatus 200. The beam exposure apparatus 200 is an apparatus that performs beam exposure on the substrate S to be exposed based on the drawing data E, and includes an electron beam drawing apparatus for semiconductor photolithography and laser drawing used in various electronic device manufacturing processes. It can be configured using a device. When an electron beam lithography apparatus is used as the beam exposure apparatus 200, a pattern P (E) for writing is drawn on the surface of the substrate S to be exposed by an electron beam, and when a laser writing apparatus is used as the beam exposure apparatus 200, Then, the pattern P (E) for drawing is drawn on the surface of the substrate S to be exposed by the laser beam.

  In FIG. 2, for convenience of description, the outline of the bit recording area Ab is indicated by a broken line, and the outline of the unit recording area Au is indicated by a dashed line. ) Is not a component. The figure pattern actually drawn on the exposure target substrate S is a bit figure (in the example shown, a small black square) painted with individual bits and a cross-shaped alignment mark Q.

  As described above, the drawing data E is data used to be applied to the beam exposure apparatus 200 to draw the drawing pattern P (E) on the substrate S to be exposed. It must be dependent on the device 200. At present, when an arbitrary figure pattern is drawn using an electron beam drawing apparatus or a laser drawing apparatus used for general LSI design, drawing data in a vector format indicating an outline of the figure pattern is used. . Therefore, in practice, the drawing data generation unit 160 only needs to generate the drawing data E indicating the outline of each bit figure or alignment mark.

  FIG. 3 is an enlarged view of the unit recording graphic pattern R (U1) shown in FIG. FIG. 2 shows an example of a small square filled with black as a bit figure indicating the bit “1”. However, in the example shown in FIG. 3, each bit figure F is expressed as vector data indicating a square outline. Is done. Similarly, the alignment marks Q1 to Q4 arranged at the four corners are expressed as vector data indicating a cross-shaped outline. The beam exposure apparatus 200 performs a process of performing beam exposure on an inner portion of the outline based on the drawing data E indicating the outline of each bit figure F and the alignment marks Q1 to Q4. Accordingly, as shown in FIG. 2, a square or cross-shaped graphic pattern painted black is formed on the exposure target substrate S.

  FIG. 3 illustrates horizontal grid lines X1 to X7 arranged at equal intervals and vertical grid lines Y1 to Y7 arranged at equal intervals. Each of these grid lines plays a role in determining the arrangement position of each bit figure F and the alignment marks Q1 to Q4. That is, if each intersection of the horizontal grid lines X1 to X7 and the vertical grid lines Y1 to Y7 is referred to as a grid point L, each bit figure F or alignment mark Q1 to Q4 has one of the centers. Are arranged at the position of the lattice point L.

  For example, the alignment mark Q1 is arranged on a grid point where the grid lines X1 and Y1 intersect, the alignment mark Q2 is arranged on a grid point where the grid lines X1 and Y7 intersect, and the alignment mark Q3 is X7 and Y1 are arranged on a lattice point where they intersect, and the alignment mark Q4 is arranged on a lattice point where lattice lines X7 and Y7 intersect.

  Further, 25 grid points at which the five horizontal grid lines X2 to X6 and the five vertical grid lines Y2 to Y6 intersect each other are represented by a unit bit matrix B of 5 rows and 5 columns shown in the middle part of FIG. U1), a bit figure F is arranged at a lattice point position corresponding to bit “1” in the unit bit matrix B (U1) (as described above, a lattice point position corresponding to bit “0”) The bit figure F may be arranged at the same time.)

  In general terms, the unit bit graphic pattern generation unit 140 converts the individual bits forming the unit bit matrix B (Ui) having m rows and n columns into grid points arranged in a matrix of m rows and n columns. L, and a process of generating a unit bit figure pattern P (Ui) by arranging a bit figure F of a predetermined shape on a lattice point L corresponding to a bit “1” or a bit “0”.

  Of course, the figures included in the actual drawing data E, that is, the figures included in the drawing pattern P (E) are only the individual bit figures F and the individual alignment marks Q1 to Q4. The grid lines X1 to X7, Y1 to Y7, the outline (dashed line) of the bit recording area Ab, and the outline (dashed line) of the unit recording area Au are not actually drawn.

  Note that the drawing data E also includes information indicating the actual size of the drawing pattern P (E) to be drawn on the exposure target substrate S, and this actual size indicates the drawing accuracy of the beam exposure apparatus 200 used. It should be set in consideration of this.

  At present, a pattern having a size of about 40 nm can be stably formed on a substrate S in a patterning process using a high-precision electron beam lithography apparatus used for general LSI design. Therefore, if such an electron beam lithography apparatus is used as the beam exposure apparatus 200, the illustrated grid line interval (pitch of the grid points L) can be set to about 100 nm, and the bit figure F having a side of about 50 nm can be set. It is quite possible to form When such a fine figure pattern is drawn, actually, the bit figure F does not become an accurate square and the alignment marks Q1 to Q4 do not become an accurate cross, but there is no practical problem. .

  In the first place, the bit figure F only has to play the role of determining the binary state of whether there is a figure at the position of the lattice point L, and therefore the shape may be a rectangle, a circle, or an arbitrary shape. Also, since the alignment marks Q1 to Q4 need only play the role of indicating the position of the bit recording area Ab, any shape may be used as long as it can be distinguished from the bit figure F. Therefore, if an electron beam lithography system having a performance capable of stably forming a figure having a size of about 40 nm is used, the bit figure F can be arranged at a pitch of about 100 nm in length and width as described above. Thus, it is possible to record information with a high degree of integration.

  On the other hand, when the laser writing apparatus is used as the beam exposure apparatus 200, the spot diameter of the laser beam depends on the wavelength of the laser beam to be used, and its minimum value is almost equal to the wavelength. For example, when an ArF excimer laser is used, since the spot diameter is about 200 nm, the degree of integration of information recording is slightly reduced as compared with the case where an electron beam lithography apparatus is used. Information recording with the same degree of integration as the medium is possible.

  In the example shown in FIG. 3, the unit bit figure pattern P (U1) is a pattern arranged in a rectangular (square) bit recording area Ab, and alignment marks Q1 to Q4 are added thereto. The unit recording graphic pattern R (U1) formed by this operation is also a pattern arranged in the rectangular (square) unit recording area Au. In practicing the prior application, the bit recording area Ab and the unit recording area Au do not necessarily have to be rectangular areas, but as shown in the lower part of FIG. 2, a plurality of unit recording graphic patterns R (U1 Considering that the drawing pattern P (E) is generated by arranging the drawing patterns P (E4) to R (U4), it is efficient that both the bit recording area Ab and the unit recording area Au are rectangular areas.

  Therefore, in practice, the unit bit figure pattern generation unit 140 generates the unit bit figure pattern P (Ui) arranged in the rectangular bit recording area Ab, and the unit recording figure pattern generation unit 150 By adding the alignment marks Q1 to Q4 to the outside of the rectangular bit recording area Ab, the unit recording arranged in the rectangular unit recording area Au including the bit recording area Ab and the alignment marks Q1 to Q4 is performed. It is preferable to generate the graphic pattern R (Ui) for use. Then, the drawing data generation unit 160 arranges these rectangular unit recording areas Au in a two-dimensional matrix, thereby drawing a plurality of unit recording graphic patterns R (U1) to R (U4). The pattern P (E) is generated, and the drawing data E for drawing the drawing pattern P (E) can be generated.

  The size of the unit recording area Au may be set arbitrarily. For example, in the case of the example shown in FIG. 3, a unit recording area Au having a square of 50 μm on a side is defined, and bit patterns F are arranged at a pitch of about 100 nm in length and width, so that one unit recording area Au About 30 KB of information can be recorded. Therefore, for example, a square substrate having a side of about 150 mm is used as an information recording medium, and unit recording areas Au each having a square of 50 μm on a substrate are arranged in a two-dimensional matrix. As much as 270 GB of data can be recorded on one sheet.

<<<< §2. Formation of physical structure pattern on medium >>>>>
Here, the exposure process by the beam exposure apparatus 200 shown in FIG. 1 and the patterning process by the patterning apparatus 300 will be described in more detail. As described in §1, the beam exposure apparatus 200 is an apparatus that performs beam exposure using an electron beam or a laser beam on a substrate S serving as an information recording medium based on drawing data E. This is an apparatus for generating an information recording medium on which a physical structure pattern (drawing pattern P (E)) according to the drawing data E is formed by performing a patterning process on the exposed substrate S.

  In actuality, these apparatuses can be directly used as the apparatus for semiconductor lithography used in the LSI manufacturing process. In other words, the beam exposure process by the beam exposure device 200 and the patterning process by the patterning device 300 can be performed using a conventional general LSI manufacturing process as it is. However, drawing data used in manufacturing an LSI is data indicating a figure pattern for configuring each region of a semiconductor element such as a channel region, a gate region, a source region, a drain region, and a wiring region. On the other hand, the drawing data E used in the invention of the prior application is a bit figure F indicating a data bit “1” or “0” and data indicating a figure pattern for forming an alignment mark Q used at the time of reading. Become.

  FIG. 4 is a side sectional view showing a specific example of the exposure step by the beam exposure apparatus 200 and the patterning step by the patterning apparatus 300 shown in FIG. 1 (only the cut surface is shown, and the inner structure is not shown). First, an exposure target substrate S as shown in FIG. 4A is prepared. In the case of this example, the exposure target substrate S is composed of the layer to be molded 10 and the resist layer 20. Although an example using a single resist layer 20 is shown here, a resist layer composed of two or more layers may be used if necessary in a patterning step described later. Further, not only an organic film such as a resist but also an inorganic film (a so-called hard mask functioning as an etching stopper) such as a metal film may be used together.

  Here, the layer to be molded 10 is a layer to be molded in the patterning step, and is finally a part to be the information recording medium M on which digital data is recorded. As described above, the object of the invention of the prior application is to enable information recording while maintaining long-term durability. Therefore, the layer 10 to be molded is made of a substrate made of a material suitable for achieving such an object. You can use. Specifically, as a transparent material, a glass substrate, particularly a quartz glass substrate, is optimally used as the layer 10 to be molded. Of course, it is also possible to use an opaque material such as a silicon substrate as the molded layer 10. Inorganic materials such as a quartz glass substrate and a silicon substrate are hardly damaged by physical damage and hardly affected by chemical contamination, and are the most suitable materials to be used for the information recording medium in the prior invention.

  On the other hand, as the resist layer 20, a material suitable for patterning the layer to be molded 10 may be used. That is, a material whose composition is changed by exposure to an electron beam or a laser beam and has a property of functioning as a protective film in an etching step for the layer to be molded 10 may be used. Of course, a positive resist having the property of dissolving exposed portions during development may be used, or a negative resist having a property of dissolving non-exposed portions during development may be used.

  The shape and size of the exposure target substrate S may be arbitrary. At present, as a quartz glass substrate generally used as a photomask, a rectangular substrate having a standard size of 152 × 152 × 6.35 mm is often used. Further, as the silicon substrate, a disc-shaped wafer having a thickness of about 1 mm according to a standard such as a diameter of 6 inches, 8 inches, or 12 inches is often used. As the exposure target substrate S, a substrate in which these standard substrates are used as the molding target layer 10 and the resist layer 20 is formed on the upper surface thereof may be used.

  Hereinafter, for convenience of explanation, an example in which a quartz glass substrate is used as the molded layer 10 and a positive resist is used as the resist layer 20 will be described. Therefore, the exposure target substrate S shown in FIG. 4A is a substrate in which the positive resist layer 20 is formed on the quartz glass substrate 10. Of course, the invention of the prior application is not limited to such an embodiment.

  As a result, the beam exposure apparatus 200 shown in FIG. 1 performs beam exposure on the surface of the resist layer 20 on the exposure target substrate S having the layer to be molded 10 and the resist layer 20 covering the layer. FIG. 4B shows an exposure process by the beam exposure apparatus 200. As described in §1, the exposure by the beam exposure apparatus 200 is performed only on the inside of the bit figure F and the inside of the alignment mark Q. Therefore, the resist layer 20 is divided into an exposed part 21 and a non-exposed part 22 through an exposure process. Here, the chemical composition of the non-exposed portion 22 remains unchanged, but the chemical composition of the exposed portion 21 changes.

  The patterning device 300 is a device that performs patterning on the substrate S after such an exposure process has been completed, and has a developing unit 310 and an etching unit 320 as shown in FIG.

  The developing section 310 is provided with a developing solution having a property of dissolving the exposed portion 21 (when a positive resist is used) or the non-exposed portion 22 (when a negative resist is used) of the resist layer. A development process is performed in which S is impregnated to leave a part of the remaining portion. FIG. 4C shows a state in which such a development process is performed on the substrate S shown in FIG. 4B. In the embodiment shown here, since the positive resist is used, the exposed portion 21 is dissolved in the developing solution by the developing process, and the non-exposed portion 22 remains as the remaining portion 23.

  On the other hand, the etching processing unit 320 performs an etching process on the developed substrate S. In the case of the embodiment shown in FIG. 4C, the layer to be molded 10 is etched using the remaining portion 23 as a mask. Specifically, the substrate S shown in FIG. 4 (c) may be impregnated with an etchant having a higher corrosiveness to the molding layer 10 than a corrosiveness to the remaining portion 23 of the resist layer (of course, dry etching). For example, a method that does not impregnate the etching solution may be used.)

  FIG. 4D shows a state in which the etching processing by the etching processing unit 320 has been performed. The portion of the upper surface of the molding layer 10 that is covered with the remaining portion 23 serving as a mask is not corroded, but the exposed portion is corroded and a recess is formed. Thus, the molded layer 10 is processed into the molded layer 11 having the uneven structure formed on the upper surface. Thereafter, the etching processing section 320 has a processing function of peeling and removing the remaining portion 23 of the resist layer and cleaning and drying the layer 11 to be molded.

  Through such a process, finally, the processed layer 11 as shown in FIG. 4 (e) is obtained. The molding layer 11 thus obtained is nothing less than the information recording medium M1 on which digital data has been written by the information storage device according to the invention of the prior application. As shown in the figure, a physical uneven structure is formed on the upper surface of the information recording medium M1, and the bit “1” and the bit “0” are expressed by the concave portion C and the convex portion V. Therefore, by detecting whether the medium surface forms the concave portion C or the convex portion V at the position indicated by the thick dashed line in the figure (the position corresponding to the lattice point L shown in FIG. 3), Reading of the bit “1” and the bit “0” becomes possible.

  Of course, it is also possible to adopt a recording method in which the concave portion C is set to the bit “0” and the convex portion V is set to the bit “1”, contrary to the illustrated example. Which of the bits is "0" and which is the bit "1" is a matter determined according to the process described above. For example, in the case of the example described in §1, in the unit bit figure pattern generation unit 140, the bit figure F is arranged at the position of the lattice point L corresponding to the bit “1” of the unit bit matrix. If the bit figure F is arranged at the position of the lattice point L corresponding to the bit “0”, the bit information of the concave portion and the convex portion is reversed. Also, when a negative resist is used as the resist layer 20 instead of a positive resist, the relationship between the concave portions and the convex portions is reversed.

  The information recording medium M1 thus created has a feature that it has long-term durability, information is recorded with a high degree of integration, and information can be read out by a universal method.

  That is, when a material such as a quartz glass substrate or a silicon substrate is used for the layer 10 to be molded, deterioration due to aging, the action of water or heat, as compared with conventional information recording media such as paper, film, and record discs. It is less susceptible to damage due to damage, and can be durable on a semi-permanent time scale of hundreds of years, similar to ancient stone. Of course, the durability can be obtained for a much longer period than a magnetic recording medium, an optical recording medium, a semiconductor recording medium, etc., which are generally used as data recording media for computers. Therefore, the invention of the prior application is most suitable for use in preserving information such as an official document in which it is desirable to record information semipermanently.

  Further, as described in §1, the beam exposure apparatus 200 can perform fine exposure with an electron beam or a laser beam, and thus can record information with an extremely high degree of integration. For example, if a high-definition electron beam drawing apparatus is used, the bit figure F can be written at a pitch of about 100 nm, and the capacity of about 100 GB to 1 TB is applied to the above-described standard size photomask or silicon substrate. It is possible to save the information that you have.

  Furthermore, the information recording medium according to the invention of the prior application is characterized in that the binary information of the bit is directly recorded as a physical structure such as unevenness, so that the information can be read out by a universal method. That is, the above-mentioned Patent Documents 1 and 2 disclose a technique for recording information three-dimensionally in a cylindrical quartz glass as a medium, but the three-dimensionally recorded information is recorded in the medium. In order to read information, a dedicated reading device using computer tomography or the like is required, and special arithmetic processing such as Fourier transform processing is required. Therefore, for example, even if a cylindrical recording medium remains intact several hundred years later, information cannot be read unless the technology of a dedicated reading device is inherited.

  On the other hand, since the binary information of bits is directly recorded as a physical structure on the information recording medium created by the information storage device according to the prior invention, the recording surface is enlarged by some method and the image is recorded. If it can be recognized as, it is possible to read at least the bit information itself. In other words, although the information recording medium according to the prior application invention itself is a three-dimensional structure, the recording of the bit information is performed only two-dimensionally. Even if excavated hundreds or thousands of years later, bit information can be read out by a universal method.

  As described above, with the information storage device according to the prior application, the uneven structure including the concave portion indicating one of the bits “1” and the bit “0” and the convex portion indicating the other is formed on the surface of the quartz glass substrate or the silicon substrate. The example of forming the physical structure pattern having the above has been described. However, in implementing the invention of the prior application, the physical structure indicating the bit information is not necessarily limited to the concavo-convex structure. Therefore, some variations of the method of forming the physical structure on the medium will be described with reference to the side sectional view of FIG. 5 (only the cut surface is shown, and the inner structure is not shown).

  FIG. 5A shows a physical structure pattern having a network structure including a through-hole H indicating one of a bit “1” and a bit “0” and a non-hole N indicating the other by the patterning apparatus 300. It is a sectional side view which shows the example formed. In the illustrated net-like structure 12, a position indicated by a thick dashed line is a position corresponding to the lattice point L shown in FIG. 3, and the position is a through hole H or a non-hole portion N (a through hole is formed). Bit "1" and bit "0" as shown in the figure.

  As described above, in the case of the information recording medium shown in FIG. 5A, the bits are represented by the presence or absence of the through holes instead of the concavo-convex structure. Therefore, the medium itself constitutes a net-like structure. The basic principle of recording bit information at the position of point L is exactly the same as the basic embodiment shown in FIG. Of course, the bit “0” may be expressed by the through-hole H and the bit “1” may be expressed by the non-hole N. When the network structure 12 shown in FIG. 5A is used as the information recording medium M, in the etching step (FIG. 4D) by the etching processing section 320, the etching processing is continued until the lower surface of the layer 10 to be formed is reached. In this case, the through hole H may be formed.

  On the other hand, FIGS. 5B to 5D are side sectional views showing a modification in which an additional layer is formed on the surface of the concave portion C and / or the convex portion V of the information recording medium M1 shown in FIG. 4E. is there. In the case of the modification shown in FIG. 5B, the additional layer 31 is formed on both surfaces of the concave portion C and the convex portion V, and in the case of the modification shown in FIG. Only the additional layer 32 is formed, and in the case of the modification shown in FIG. 5D, the additional layer 33 is formed only on the surface of the concave portion C.

  As the additional layers 31, 32, and 33, light-reflective materials (for example, metals such as aluminum, nickel, titanium, silver, chromium, silicon, molybdenum, and platinum, alloys, oxides, and nitrides of these metals) Alternatively, a light-absorbing material (for example, a material formed of a compound such as a metal oxide or a nitride, such as chromium oxide or chromium nitride in the case of chromium) can be used. If an additional layer made of a light-reflective material is formed, the concave portion C and the convex portion V can be distinguished based on a difference in behavior of reflected light at the time of reading, and the additional layer made of a light-absorbing material can be distinguished. Is formed, the concave portion C and the convex portion V can be distinguished at the time of reading based on the difference in the light absorption mode. Therefore, by forming such an additional layer, an effect of making information reading easier can be obtained.

  Further, instead of forming another layer having a clear boundary surface like an additional layer, the same effect can be obtained by doping the surface of the concave portion C or the convex portion V with an impurity. For example, an information recording medium having a concavo-convex structure is made of quartz, and the surface thereof is doped with boron, phosphorus, rubidium, selenium, copper, or the like, and if the impurity concentration at the surface portion is changed, an additional layer is provided. Similarly, a light-reflecting property or a light-absorbing property can be given to the surface portion, and an effect of making information reading easier can be obtained. Specifically, in the case of the impurities described above, an effect of absorbing ultraviolet light is obtained when the concentration is about 100 ppm or more, and an effect of increasing the reflectance is obtained when the concentration is about 1000 ppm or more.

  In particular, if the additional layer 32 made of a light-reflective or light-absorbing material is formed only on the projection V as in the example shown in FIG. Since the difference between the light or the scattered light and the reflected light or the scattered light obtained from the convex portion V becomes remarkable, the bit “1” and the bit “0” can be easily distinguished. Similarly, as in the example shown in FIG. 5D, even when the additional layer 33 made of a light-reflective or light-absorbing material is formed only in the concave portion C, the readout obtained from the concave portion C at the time of reading is performed. The difference between the light or the scattered light and the reflected light or the scattered light obtained from the convex portion V becomes remarkable, so that the bit can be easily identified.

  As shown in FIG. 5B, in order to form the additional layer 31 on both the surface of the concave portion C and the surface of the convex portion V, after obtaining the information recording medium M1 shown in FIG. Further, a process of depositing the additional layer 31 on the entire upper surface of the recording medium may be performed. In order to obtain a structure in which the additional layer 32 is formed only on the surface of the convex portion V as in the example shown in FIG. 5C, instead of the exposure target substrate S shown in FIG. A substrate having a structure in which an additional layer is sandwiched between the molding layer 10 and the resist layer 20 may be used. In order to obtain a structure in which the additional layer 33 is formed only on the surface of the concave portion C as in the example shown in FIG. 5D, the resist layer is formed when the etching process shown in FIG. In such a state that the remaining portion 23 is left as it is, a process of depositing an additional layer on the entire upper surface is performed, and then the remaining portion 23 may be peeled and removed.

  On the other hand, the modification shown in FIG. 5E is one in which the molding layer 51 itself formed on the upper surface of the support layer 40 is made of a light reflecting or light absorbing material. For example, if the support layer 40 is formed of a quartz glass substrate, an additional layer made of aluminum is formed on the upper surface thereof, a resist layer is further formed on the upper surface thereof, and a process according to the process illustrated in FIG. 4 is performed. A structure as shown in FIG. 5 (e) can be obtained. In this case, in the etching process, a corrosive solution having corrosiveness to aluminum may be used. In this structure, since the surface of the concave portion C is made of quartz glass and the surface of the convex portion V is made of aluminum, the effect of easily identifying bits at the time of reading can be obtained.

  In practical use, when the modification shown in FIG. 5A is adopted, it is preferable that the net-like structure 12 is made of an opaque material. Then, the portion of the through hole H becomes a portion that transmits light, and the portion of the non-hole portion N becomes a portion that does not transmit light. Therefore, a remarkable difference can be recognized at the time of reading, which will be described later. Becomes easier.

  On the other hand, when the modifications shown in FIGS. 5 (c) to 5 (e) are adopted, the molded layer 11 or the support layer 40 is made of a transparent material, and the additional layers 32, 33, 51 are made of an opaque material. Is preferred. Then, the portion where the additional layer is not formed is a portion that transmits light, and the portion where the additional layer is formed is a portion that does not transmit light. The difference can be recognized, and the bit can be easily identified.

<<<< §3. Basic Embodiment of Information Reading Apparatus According to Invention of Prior Application >>>>>
In §1 and §2, the configuration and operation of the information storage device for storing information on the information recording medium have been described. Here, the configuration and operation of an information reading device used to read information recorded in this manner will be described.

  FIG. 6 is a block diagram showing a configuration of a basic embodiment of an information reading device according to the invention of the prior application. The information reading device according to this embodiment is a device that performs a function of reading digital data stored in the information recording medium M using the information storage device shown in FIG. Computer 500.

  Here, the image photographing apparatus 400 is a component that enlarges and photographs a photographing target area forming a part of the recording surface of the information recording medium M, and captures the obtained photographed image as image data. It has an image sensor 410, an enlargement optical system 420, and a scanning mechanism 430.

  The imaging element 410 can be configured by, for example, a CCD camera, and has a function of capturing an image in a predetermined imaging target area as digital image data. The magnifying optical system 420 is configured by an optical element such as a lens, and has a role of enlarging a predetermined imaging target region that forms a part of the recording surface of the information recording medium M and forming the enlarged image on the imaging surface of the imaging device 410. Fulfill. The scanning mechanism 430 performs a scanning process (changing a position and an angle) on the image sensor 410 and the magnifying optical system 420 so that the imaging target area sequentially moves on the recording surface of the information recording medium M. Fulfill.

  FIG. 5 shows a variation of the information recording medium M. However, in the case of the information recording medium M having the network structure 12 shown in FIG. The information can also be read out for, and both the upper and lower surfaces constitute the recording surface. On the other hand, as shown in FIGS. 4 (e) and 5 (b) to 5 (e), in the case of the information recording medium M having an uneven structure on the upper surface, the upper surface is a recording surface. Therefore, when the molded layer 11 or the support layer 40 is made of a transparent material, information can be read out by photographing from either the upper side or the lower side, but these are made of an opaque material. If so, it is necessary to shoot from above.

  As shown, the read processing computer 500 includes a captured image storage unit 510, a bit recording area recognition unit 520, a unit bit matrix recognition unit 530, a scan control unit 540, and a data restoration unit 550. Hereinafter, the functions of these units will be described in order. However, each of these units is actually a component realized by incorporating a dedicated program into a computer, and the reading processing computer 500 can be configured by installing a dedicated program into a general-purpose computer. it can.

  First, the captured image storage unit 510 is a component that stores a captured image captured by the image capturing device 400. That is, it has a function of storing, as digital image data, an image in a predetermined photographing target region photographed by the image sensor 410. As described above, the image capturing apparatus 400 is provided with the scanning mechanism 430, and the capturing target area sequentially moves on the recording surface of the information recording medium M. A captured image is obtained. The captured image storage unit 510 has a function of storing image data sequentially provided from the image sensor 410 in this way.

  On the other hand, the bit recording area recognizing unit 520 performs a process of recognizing each bit recording area Ab from the captured image stored in the captured image storage unit 510. In the prior application, as described with reference to FIG. 2, the digital data D to be stored is divided into a plurality of unit data U1, U2, U3,. Are recorded in the individual bit recording areas Ab as P (U2), P (U3),. Therefore, at the time of the reading process, first, after recognizing the individual bit recording area Ab, each bit constituting the unit data Ui is determined based on the individual unit bit graphic pattern P (Ui) recorded therein. Will be read.

  As described in §2, the alignment mark Q and the bit figure F are recorded on the recording surface of the information recording medium M as a physical structure pattern such as an uneven structure and the presence or absence of a through hole. For this reason, the alignment mark Q, the bit figure F, or the contour thereof are expressed as a light / dark distribution on the captured image, and the position on the captured image is determined by using the existing pattern recognition technology. The alignment mark Q and the bit figure F can be recognized.

  First, recognition of each bit recording area Ab is performed by detecting the alignment mark Q. Since a figure different from the bit figure F is used for the alignment mark Q, the bit recording area recognizing unit 520 searches the captured image stored in the captured image storage unit 510 to perform the alignment. The mark Q can be detected. For example, in the example shown in the lower part of FIG. 2, the bit mark F is square, while the alignment mark Q is cross-shaped. It is possible to recognize the alignment mark Q and determine its position.

  Since the alignment mark Q is arranged at a specific position with respect to the bit recording area Ab, if the alignment mark Q can be recognized on the captured image, the position of the bit recording area Ab can be specified. . For example, if the captured image includes the unit recording graphic pattern R (U1) as shown in FIG. 3, if four alignment marks Q1 to Q4 can be recognized, the positions of the four alignment marks Q1 to Q4 can be recognized. A square bit recording area Ab having alignment marks Q1 to Q4 near four corners can be recognized.

  If the image photographing apparatus 400 has a function of photographing a photographing target area having a size that can include at least one unit recording area Au, four sets as shown in FIG. Can be recognized, and the bit recording area Ab can be recognized.

  Of course, if the shooting target area is set at a position straddling the unit recording area Au adjacent to each other, the four sets of alignment marks Q1 to Q4 indicating the position of the same bit recording area Ab cannot be correctly recognized. . In this case, the bit recording area recognizing unit 520 can recognize the positional deviation of the imaging target area based on the correlation between the recognized alignment marks, and thus reports the positional deviation to the scanning control unit 540. Is performed.

  Upon receiving such a report of the displacement, the scanning control unit 540 controls the image capturing apparatus 400 to adjust the displacement. Specifically, an instruction is given to the scanning mechanism 430 to move the imaging target area in a predetermined correction direction by a predetermined correction amount. By performing such adjustment, as shown in FIG. 3, it is possible to obtain a correct photographed image in which the alignment marks Q1 to Q4 are arranged at appropriate positions at the four corners, and the correct photographed image is obtained for the bit recording area Ab. The reading process can be performed. As described above, the first role of the scanning control unit 540 is an adjustment process for correcting the positional shift when the imaging target area is displaced from the unit recording area Au.

  The second role of the scanning control unit 540 is a scanning process for setting the next unit recording area Au as a new imaging target area after the imaging using one unit recording area Au as the imaging target area is completed. For example, in the case of the example shown in the lower part of FIG. 2, when the photographing of the unit recording area Au (U1) in which the unit recording graphic pattern R (U1) is recorded is completed, subsequently, the unit recording graphic pattern R ( It is necessary to take an image of the unit recording area Au (U2) in which U2) is recorded, and thereafter, further record the unit recording area Au (U3) in which the unit recording graphic pattern R (U3) is recorded. It is necessary to sequentially move the photographing target area and the unit recording area Au (U4) in which the recording graphic pattern R (U4) is recorded.

  After all, it can be said that the scanning control unit 540 is a component that performs control for changing the image capturing target area by the image capturing apparatus 400 so as to obtain captured images for all the bit recording areas to be read. This control can be performed by feedback control based on the detection result of the alignment mark Q by the bit recording area recognition unit 520, and the above-described fine adjustment can be performed even when a position shift occurs.

  When the bit recording area recognizing unit 520 recognizes the i-th bit recording area Ab (i) from the captured image, the information of the i-th bit recording area Ab (i) is sent to the unit bit matrix recognizing unit 530. Given. The unit bit matrix recognition unit 530 performs a process of recognizing the unit bit matrix based on the pattern in the bit recording area Ab (i). For example, in the case of the example shown in FIG. 3, based on the unit bit graphic pattern P (U1) recorded in the bit recording area Ab, a unit bit matrix B composed of five rows and five columns as shown in the middle part of FIG. (U1) can be recognized.

  In the example shown in FIG. 3, as described in §1, horizontal grid lines X1 to X7 arranged at equal intervals and vertical grid lines Y1 to Y7 arranged at equal intervals are defined. A grid point L is defined as each intersection, and the individual bit figures F and the alignment marks Q1 to Q4 are arranged so that the center thereof is located at any of the grid points L. Therefore, the recognition process of unit bit matrix B (U1) by unit bit matrix recognition unit 530 can be performed according to the following procedure.

  First, the horizontal grid lines X1 and X7 and the vertical grid lines Y1 and Y7 are recognized based on the center point positions of the four sets of alignment marks Q1 to Q4 recognized by the bit recording area recognition unit 520. Subsequently, the horizontal grid lines X2 to X6 are defined so as to equally divide the horizontal grid lines X1 and X7, and the vertical grid lines are equally divided between the vertical grid lines Y1 and Y7. Y2 to Y6 are defined. Then, 25 grid point positions where the horizontal grid lines X2 to X6 and the vertical grid lines Y2 to Y6 intersect are determined, and it is determined whether or not the bit figure F exists at each of these grid point positions. Processing may be performed. As described above, since the bit figure F can be recognized based on the light and dark distribution on the captured image, the bit “1” is associated with the grid point position where the bit figure F exists, and If a bit "0" is associated with, a unit bit matrix B (U1) having five rows and five columns shown in the middle part of FIG. 2 can be obtained.

  Based on the i-th unit bit graphic pattern P (Ui) thus recorded in the i-th bit recording area Ab (i), the unit bit matrix recognizing unit 530 generates the i-th unit bit matrix B A process for recognizing (Ui) is performed, and the result is provided to the data restoration unit 550. The unit bit matrix recognizing unit 530 repeatedly executes the unit bit matrix recognizing process on all the bit recording regions recognized by the bit recording region recognizing unit 520 in the same manner.

  The data restoring unit 550 generates the unit data Ui from the individual unit bit matrices B (Ui) recognized by the unit bit matrix recognizing unit 530 in this way, and synthesizes the individual unit data Ui to obtain the digital data to be saved. The data D is restored. For example, in the case of the example shown in FIG. 2, four sets of unit data U1 to U4 are generated from four sets of unit bit matrices B (U1) to B (U4), and these are connected to form the original digital data D. Will be restored.

  The basic embodiment of the information reading device according to the invention of the prior application has been described above with reference to the block diagram of FIG. 6, but the information reading from the information recording medium M created by the information storage device according to the invention of the prior application is described. Reading does not necessarily need to be performed using such an information reading device. For example, information can be read using an optical measuring instrument, a scanning electron microscope, an atomic force microscope, or the like.

  As described above, the information recording medium M created by the information storage device according to the invention of the prior application has the universal property that binary information of bits is directly recorded as a physical structure. If an image indicating the presence or absence of the bit figure F can be obtained by being enlarged by some method, the bit information can be read. Therefore, even when the information recording medium M is excavated several hundred years or thousands of years later, bit information can be read if any physical structure recognizing means exists at that time. Of course, if stored underground, foreign matter may adhere to the recording surface and become contaminated, but these foreign matter can be easily removed by washing. There is no problem in reading information.

  Regardless of which read method is adopted, it is possible to read in a non-contact state with respect to the information recording surface. (Even if an atomic force microscope is used, the non-contact mode can be used if the non-contact mode is used.) The recording surface is not physically damaged during the reading process, and even if the reading process is repeatedly performed, the information recording surface is not likely to be worn.

  When the information reading device shown in FIG. 6 is combined with the information storage device shown in FIG. 1, while reading information from a part of the recorded area of the information recording medium M, the information can be read from an unrecorded area adjacent to the recorded area. It becomes possible to store new information. Therefore, it is also possible to realize a write-once information storage device that sequentially records new information on one information recording medium. Of course, if a device that combines an information storage device and an information reading device is used, after performing a storage process of writing information on a medium using the information storage device, verification of the information stored using the information reading device is performed. It can be done and modified as needed.

<<<< §4. Variation of alignment mark >>>>>
In §3, the basic embodiment of the information reading device has been described. Therefore, here, in consideration of the convenience at the time of reading the information, variations of the alignment mark recorded at the time of storing the information will be described. While the bit figure F plays a role of indicating original information to be stored, the alignment mark Q is meta information used for positioning at the time of reading information.

  In the embodiment described so far, the unit recording graphic pattern generation unit 150, as illustrated in FIG. 3, for example, is located outside the four corners of the rectangular bit recording area Ab, and has a cross-shaped alignment mark Q1. The processing for generating a unit recording graphic pattern is performed by adding .about.Q4. These alignment marks Q1 to Q4 are used for alignment for the bit recording area recognition unit 520 in the information reading device shown in FIG. 6 to recognize the bit recording area Ab.

  However, the shape, arrangement position, and number of these alignment marks Q are not limited to the above-described embodiment. That is, the shape of the alignment mark Q may be any shape as long as it can be distinguished from the bit figure F. Further, the arrangement position does not necessarily need to be arranged outside the four corners of the bit recording area Ab, and may be arranged, for example, at the center position of the four sides of the bit recording area Ab. Further, the number of the alignment marks Q does not necessarily need to be four.

  FIG. 7 is a plan view showing a variation of the alignment mark Q used in the invention of the prior application. In each case, the dashed square indicates the bit recording area Ab (for convenience, the inside is hatched instead of drawing a bit figure), and the dashed-dotted square indicates the unit recording area Au. Are alignment marks Q.

  FIG. 7A shows an example in which the alignment marks Q11 and Q12 are arranged near the upper left corner and the upper right corner of the rectangular bit recording area Ab. If the direction connecting the center points of the two sets of alignment marks Q11 and Q12 is defined as the horizontal coordinate axis X, it is possible to indicate the direction of one coordinate axis regarding the arrangement of the bit recording area Ab. At the time of reading, the horizontal coordinate axis X can be recognized based on the two sets of alignment marks Q11 and Q12, and the vertical coordinate axis Y can be defined as an axis orthogonal to the horizontal coordinate axis X. As long as the bit recording area Ab has a correct rectangle, no problem occurs in the reading process of each bit. From this point of view, if two sets of alignment marks are added to one bit recording area Ab, practically, there is no problem in the reading process.

  Of course, alignment marks may be arranged near the upper left corner and near the lower left corner of the bit recording area Ab to define the vertical coordinate axis Y. In short, the unit recording graphic pattern generation unit 150 adds a total of two sets of alignment marks arranged near the outside of two corners that are not diagonal among the four corners of the rectangular bit recording area Ab. , A unit recording graphic pattern may be generated.

  On the other hand, FIG. 7 (b) shows a unit by adding a total of three sets of alignment marks Q21, Q22, Q23 arranged near the outer three corners of the four corners of the rectangular bit recording area Ab. This is an example of generating a recording graphic pattern. By using the three sets of alignment marks Q21, Q22, Q23 in this manner, both the horizontal coordinate axis X and the vertical coordinate axis Y can be defined as shown in the figure, and the accuracy of the read processing of each bit can be further improved. It is possible to increase.

  When three sets of alignment marks are used in this way, as shown in an example shown in FIG. 8, the arrangement of the three sets of alignment marks is different for unit recording graphic patterns adjacent to each other. Is preferred. FIG. 8 shows a state in which a plurality of unit recording areas Au are arranged in a two-dimensional matrix. Here, regarding the unit recording areas Au (11), Au (13), Au (22), Au (31) and Au (33), the arrangement mode shown in FIG. 7B (that is, only the lower right corner is missing). FIG. 7 (b) shows the unit recording areas Au (12), Au (21), Au (23), and Au (32). Three sets of alignment marks are arranged in an arrangement mode in which the arrangement mode is reversed left and right (that is, an arrangement mode in which only the lower left corner is missing).

  In short, for the arrangement of the unit recording areas Au, a row number i (i = 1, 2, 3,...) And a column number j (j = 1, 2, 3,...) When the unit recording area is expressed as Au (ij) as shown in the figure, in the first group in which (i + j) is an even number, as shown in FIG. For the second group in which (i + j) is an odd number, an arrangement in which the alignment mark is missing only in the lower left corner as shown in FIG. ing.

  In this way, if two arrangements are defined as the arrangement of the three sets of alignment marks and different arrangements are adopted for the unit recording graphic patterns vertically or horizontally adjacent to each other, the scanning controller When the 540 scans the imaging target area, it is possible to prevent an error that skips imaging of an adjacent unit recording area.

  For example, in the example illustrated in FIG. 8, the scanning control unit 540 first captures an image of the unit recording area Au (11) as a capturing target area, and then moves the capturing target area in the right direction in the figure to the right side. Assume that control is performed with the unit recording area Au (12) to be photographed as the photographing target area. Normally, if control is performed to move by the distance corresponding to the pitch of the unit recording area Au, the next shooting target area can be moved to the position of the unit recording area Au (12). However, if an error occurs in the moving distance due to some reason and the shooting target area moves to the position of the unit recording area Au (13), the reading process for the unit recording area Au (12) is skipped. Become.

  If such an arrangement as shown in FIG. 8 is adopted, it is possible to detect an error even if such a situation occurs. In other words, if the unit recording area Au (11) is photographed and then the unit recording area Au (12) is skipped and the unit recording area Au (13) is photographed, the arrangement of the alignment marks is the same. Therefore, it can be recognized that the unit recording area Au (12) has been skipped. Therefore, processing for returning the photographing target area to the left direction in the figure can be performed, and correction can be performed so that photographing of the unit recording area Au (12) is performed. Similar correction is possible when a skip in the vertical direction occurs.

  As a method for recognizing that such a skip has occurred, a method of preparing two types of arrangement modes or a method of changing the shape of the alignment mark can be adopted. For example, FIGS. 9A and 9B show an example of a variation in which the shape of the alignment mark is changed. In the example shown in FIG. 9A, the cross-shaped mark Q31, the triangular mark Q32, and the square mark Q33 are arranged at the positions shown in FIG. 9B, whereas the example shown in FIG. In this case, a circular mark Q41, a diamond-shaped mark Q42, and an X mark Q43 are arranged at the illustrated positions. If such two types of alignment marks are used alternately vertically and horizontally, it is possible to recognize that a skip has occurred, as in the example shown in FIG.

  FIG. 10 is a plan view showing another variation of the arrangement of the alignment marks in the invention of the prior application. In this variation, the alignment marks for the unit recording area Au (11) in the example shown in FIG. 8 are changed to the alignment marks shown in FIG. 9A. That is, among the unit recording areas Au arranged in a two-dimensional matrix, only the unit recording area Au (11) arranged in the first row and the first column differs in the shape of the alignment mark used. . This is because the unit recording area Au (11) arranged in the first row and the first column is set as a reference unit recording area to be read first, and this reference unit recording area is easily set at the time of reading processing. This is a consideration to enable identification.

  When the variation shown in FIG. 10 is adopted, the unit recording graphic pattern generation unit 150 sets a specific unit recording area as a reference unit recording area, and the reference unit recording area is different from other unit recording areas. What is necessary is just to generate a unit recording graphic pattern using different reference alignment marks. In the illustrated example, the reference alignment mark shown in FIG. 9A is used for the reference unit recording area Au (11), and the normal alignment marks shown in FIG. 8 are used for the other unit recording areas. Therefore, at the time of the reading process, the reference unit recording area Au (11) to be read first can be specified by first performing the process of searching for the reference positioning mark shown in FIG. 9A. .

  That is, if the image photographing device 400 in the information reading device shown in FIG. 6 has a function of photographing a photographing target region of a size that can include at least one unit recording region Au, the image shown in FIG. Since it becomes possible to search for the reference alignment mark, the scanning control unit 540 first takes an image of the area including the reference unit recording area Au (11) based on the reference alignment mark shown in FIG. What is necessary is just to perform control to adjust the image capturing target area to the image capturing apparatus 400 so that an image is obtained. When the reading of the correct bit information from the bit recording area Ab (11) in the reference unit recording area Au (11) is completed in this way, the scanning control unit 540 changes the shooting target area according to the arrangement pitch of the unit recording areas Au. What is necessary is just to perform the control which moves sequentially.

  Of course, also in this case, as described with reference to FIG. 8, even if an error occurs in which the unit recording area Au (13) is skipped due to some circumstances, the error can be recognized and corrected. Also, fine adjustment can be made even when a slight positional shift has occurred.

  As a method of indicating the reference unit recording area Au (11), instead of using a method using a reference alignment mark different from other unit recording areas, a bit recording area Ab () in the reference unit recording area Au (11) is used. In 11), a method of arranging a specific identification mark without arranging the bit figure F can be adopted. The bit recording area Ab is an area originally used for arranging the bit figure F and recording data to be stored, but if a unique identification mark is arranged only for the reference unit recording area. By confirming the unique identification mark, the reference unit recording area can be easily recognized.

  For example, if a large star is drawn in the area Au (11) shown in FIG. 8, it can be easily recognized that the area Au (11) is the reference unit recording area. In this case, although the original information is not recorded in the area Au (11), first, the position is adjusted with the reference unit recording area Au (11) as the first imaging target area, and then the imaging target area is adjusted. Scanning may be performed to sequentially move. If the size of the reference unit recording area Au is a visible size, in the case of the above example, it is also possible to visually confirm the star mark, and the position where the reference unit recording area Au (11) is the first photographing target area. It is also possible to perform the adjustment by a manual operation visually observed by an operator.

<<<< §5. Information storage method and information read method according to the invention of prior application >>>>>
Here, a basic processing procedure when the prior application invention is grasped as a method invention of an information storage method and an information reading method will be described.

  FIG. 11 is a flowchart showing a basic processing procedure of the information storage method according to the prior application invention. This procedure is an execution procedure of an information storage method of writing and storing digital data on an information recording medium. Steps S11 to S16 are executed by the storage processing computer 100 shown in FIG. 1, and step S17 is performed. 1 is a procedure executed by the beam exposure apparatus 200 shown in FIG. 1, and step S18 is a procedure executed by the patterning apparatus 300 shown in FIG.

  First, in step S11, a data input stage in which the storage processing computer 100 inputs digital data D to be stored is executed. In the following step S12, the storage processing computer 100 executes a unit data generation step of generating the plurality of unit data Ui by dividing the digital data D in units of a predetermined bit length. Then, in step S13, the storage processing computer 100 performs a unit bit matrix generation step of generating the unit bit matrix B (Ui) by arranging the data bits constituting the individual unit data Ui in a two-dimensional matrix. In step S14, the storage processing computer 100 converts the unit bit matrix B (Ui) into a geometric pattern arranged in a predetermined bit recording area Ab to convert the unit bit graphic pattern P ( The step of generating a unit bit graphic pattern for generating Ui) is performed.

  Subsequently, in step S15, the storage processing computer 100 adds the alignment mark Q to the unit bit graphic pattern P (Ui) to generate the unit recording graphic pattern R (Ui). A generation step is performed. Then, in step S16, a drawing data generation step is executed in which the storage processing computer 100 generates drawing data E for drawing the unit recording graphic pattern R (Ui).

  Finally, in step S17, a beam exposure step of performing beam exposure using an electron beam or a laser beam on the substrate S serving as an information recording medium is executed based on the drawing data E. In step S18, the exposure is performed. By performing a patterning process on the received substrate, a patterning step of generating an information recording medium M on which a physical structure pattern corresponding to the drawing data E is formed is executed.

  On the other hand, FIG. 12 is a flowchart showing a basic processing procedure of the information reading method according to the invention of the prior application. This procedure is an execution procedure of an information reading method for reading digital data stored in the information recording medium M according to the procedure shown in FIG. 11, and step S21 is a procedure executed by the image photographing apparatus 400 shown in FIG. Steps S22 to S27 are procedures executed by the computer 500 for reading processing shown in FIG.

  First, in step S21, an image photographing step of enlarging and photographing a photographing target area forming a part of the recording surface of the information recording medium M using the image photographing device 400 and capturing the obtained photographed image as image data is performed. Be executed. Then, in step S22, the read processing computer 500 executes a captured image storing step of storing the captured image, and in step S23, the read processing computer 500 performs position adjustment from the captured image stored in the captured image storage step. A bit recording area recognition step of recognizing each bit recording area Ab by detecting the mark is performed.

  In this bit recording area recognition step, if the bit recording area Ab has been successfully recognized, the process proceeds to step S25 via step S24. However, if the bit recording area Ab has failed to be recognized, If there is a shift and the complete bit recording area Ab is not included in the captured image, the process returns to step S21, and the image capturing step is executed again. At this time, a process of changing the shooting target area by the image shooting device is performed so that a correct shot image is obtained.

  In step S25, a unit bit matrix recognition step in which the reading computer 500 recognizes the unit bit matrix B (Ui) based on the pattern in the bit recording area Ab is executed. Such processing is repeatedly executed through step S26 until the recognition of all necessary areas is completed. That is, while controlling to change the shooting target area by the image shooting apparatus so that the reading processing computer 500 can obtain shot images for all the bit recording areas Ab to be read, the image shooting step of step S21 is performed. Is repeated.

  Finally, in step S27, the read processing computer 500 generates unit data Ui from the individual unit bit matrices B (Ui) recognized in the unit bit matrix recognition step of step S25, and combines the individual unit data Ui. As a result, a data restoration step of restoring the digital data D to be saved is executed.

<<<< §6. Problems concerning the interpretation of data bits >>>>>
Next, a problem concerning a method of interpreting data bits which occurs when information is recorded as a fine physical structure pattern on a medium as in the above-mentioned prior application invention will be described. FIG. 2 shows an example in which unit data U1 constituting the first 25 bits of digital data D to be recorded is recorded as a unit bit figure pattern P (U1) arranged in a bit recording area Ab. In the case of the illustrated example, 25-bit information forming the unit bit matrix B (U1) is represented by the presence / absence of a bit figure at each position forming the 5-row, 5-column matrix. In particular, in the case of the example shown here, the bit “1” is indicated when a small bit figure F painted black is arranged, and the bit “0” is indicated when it is not arranged.

  As shown in FIG. 1, when the drawing data E for drawing such a graphic pattern is generated by the storage processing computer 100, the exposure processing by the beam exposure apparatus 200 and the patterning processing by the patterning apparatus 300 are executed. , An information recording medium M on which digital data D is recorded is created. FIG. 4 shows an example of an exposure process and a patterning process for forming a pattern corresponding to the second row in the matrix of 5 rows and 5 columns constituting the unit bit graphic pattern P (U1) shown in FIG. It is shown.

  The information recording medium M1 shown in FIG. 4 (e) is a medium obtained through such processing, and for each arrangement position of the bit information, the concave portion C has the bit “1” and the convex portion V has the bit “0”. In the case of the illustrated example, it is possible to read 5-bit data “10110”. The data corresponds to the information in the second row of the unit bit matrix B (U1) shown in FIG. 2, and the recorded data has been correctly read. On the other hand, when the concave portion C is interpreted as a bit “0” and the convex portion V is interpreted as a bit “1” when reading the information recording medium M1, in the case of the example shown, 5-bit data “01001” is read. Therefore, correct reading cannot be performed.

  As described above, when the data is read, if the method of interpreting the individual data bits (in this example, which of the concave and convex portions is interpreted as bit “1” or bit “0”) is different, the bit value Is inverted, so that correct bit information intended at the time of recording cannot be read. Needless to say, the unit bit figure pattern P (U1) illustrated in FIG. 2 is actually recorded on the information recording medium M as an extremely fine uneven structure, so that even if the actual information recording medium M is visually observed, The pattern cannot be grasped with the naked eye (a very high magnification microscope or the like is required to observe the actual pattern).

  In consideration of such circumstances, it is preferable that some information indicating a data bit interpretation method be recorded together with the information recording medium M at the time of data recording. For example, in the case of the above example, if information such as a character string such as “the concave portion is bit“ 1 ”” is written in the information recording medium M in a form that can be visually observed at the time of data recording, At the time of reading, individual data bits can be interpreted in a correct manner based on the information. Of course, if the interpretation method always focuses on the bit “1”, the character “concave” may be simply written in a form that can be visually observed.

  Specifically, the operator who performs the information reading process using the information reading apparatus shown in FIG. 6 first visually observes the information recording medium M to be read and reads "the concave portion is bit" 1 "". After obtaining the information, the unit bit matrix recognizing unit 530 may be set to interpret the concave portion as the bit “1”. In this case, the unit bit matrix recognition unit 530 recognizes the unevenness of each grid point position from the photographed image, and the bit “1” is recorded for a concave portion and the bit “0” is recorded for a convex portion. And the data bits can be recognized. Of course, if the information “the convex portion is bit“ 1 ”” is recorded on the information recording medium M, the reverse setting is performed for the unit bit matrix recognizing unit 530. Recognition may be performed by interpreting that the bit is “1” and the bit “0” is recorded in the case of a concave portion.

  However, as a method of recording the interpretation method of data bits on the medium itself, as in the above example, a method of simply recording information such as “the concave portion is bit“ 1 ”” as it is, in practice, is not practical. , Not very good. The reason will be described below.

  The first reason is that when a medium is copied by a physical method, it cannot be properly handled. At present, information recording media such as CDs and DVDs on which music and images are recorded are distributed on the market as commercial mass-produced products. These mass-produced media are usually manufactured through a physical duplication process based on the master. In a copy manufactured by such a copying process, the concave-convex structure of the original plate is reversed.

  FIG. 13 is a side sectional view showing a general duplication method of an information recording medium having a concave-convex structure formed on a surface. An information recording medium M1 serving as an original and a duplication creation medium M0 are prepared. The process of pressing the medium M0 to transfer the uneven structure formed on the surface of the medium M1 to the surface of the medium M0 is shown. FIG. 14 is a side sectional view showing a state in which a duplicate is created by the duplication method shown in FIG. That is, the copy creation medium M0 shown in FIG. 13 is changed to the medium M2 (copy) shown in FIG. Since the concave / convex structure formed on the upper surface of the information recording medium M1 serving as the original is transferred to the lower surface of the copied information recording medium M2, the concave / convex relationship is reversed.

  Therefore, the correct interpretation of the data bits for the information recording medium M2 shown in FIG. 14 is the reverse of the interpretation of the data bits for the original information recording medium M1. Specifically, as shown in the figure, in the case of the medium M1, the concave portion should be interpreted as a bit “1” and the convex portion should be interpreted as “0”, whereas in the medium M2, the convex portion should be interpreted as a bit “1”. The recess must be interpreted as "0". In consideration of the fact that the interpretation method of the data bits is reversed by the duplication process, information indicating a unique interpretation method such as “a convex portion is bit“ 1 ”” is also recorded at the time of recording. Is not preferred.

  As described above, when a so-called “pattern inversion (reversal)” occurs, a method of recording an identification mark having an asymmetric shape has been known for a long time as a method of inviting the operator to do so. For example, when a printed material is generated by an optical process using a transparent document sheet, if the document sheet is set upside down, an inverted image is formed on the printed material. In order to prevent such an error, an identification mark having an asymmetric shape may be recorded on the document sheet. For example, if a large letter "F" is recorded as an identification mark and the original sheet is set upside down, the letter "F" becomes a reverse letter (mirror image letter). You can easily recognize what you have done.

  Therefore, even in the above-mentioned prior application, if a method of recording an identification mark having an asymmetric shape is adopted, even if the concave-convex structure of the original plate is reversed by the duplication process, the person who performs the reading operation will be able to read the irregularities. It is possible to evoke that reversal has occurred.

  FIG. 15 is a plan view showing the relationship between the original M1 and its copy M2 when the method of recording a large letter "F" as an identification mark is used (the hatching indicates an area. is there). FIG. 15A is a plan view (a diagram showing the uneven structure surface) of the information recording medium M1 serving as an original. The main recording area Aα shown by hatching and the sub recording area Aβ arranged at the upper left corner. Are shown.

  Here, the main recording area Aα is an area for recording information of individual data bits constituting digital data to be recorded. Specifically, a plurality of unit recording areas Au shown in FIG. This is the area recorded. In the case of the information recording medium M1 as an original, the convex portion V indicates a bit “0” and the concave portion C indicates a bit “1”. On the other hand, the sub-recording area Aβ is an area for recording the identification mark m1 having an asymmetric shape. In the illustrated example, a large “F” character that can be visually observed is recorded as the identification mark m1.

  On the other hand, FIG. 15B is a plan view of the information recording medium M2 duplicated by performing the pressing process shown in FIG. 13 using the information recording medium M1 shown in FIG. Figure). In other words, FIG. 15A is a top view of the medium M1 shown in FIG. 14, while FIG. 15B is a bottom view of the medium M2 shown in FIG. Therefore, the sub recording area Aβ arranged at the upper left corner in the plan view of FIG. 15A is arranged at the upper right corner in the plan view of FIG. The identification mark m1 indicating the character "" has been changed to an identification mark m2 indicating the back letter of "F" in FIG.

  In the medium M2 (replica) shown in FIG. 15B, the concave and convex structure is reversed with respect to the medium M1 (original) shown in FIG. C indicates bit “0”. Therefore, when reading digital data recorded in the main recording area Aα, in the case of reading from the information recording medium M1 as an original, the convex portion V is represented by bit “0” and the concave portion C is represented by bit “1”. In the case of reading from the duplicated information recording medium M2, the convex portion V must be interpreted as bit "1" and the concave portion C must be interpreted as bit "0". Of course, if the grandchild duplication is performed using the medium M2 shown in FIG. 15B, the same interpretation as the original M1 must be performed for the grandchild duplication obtained.

  As described above, even when duplication is repeated for many generations, which interpretation should be adopted for the data bits of each version can be recognized by the identification mark m1 or m2 recorded in the sub recording area Aβ. It is. That is, if the identification mark m1 indicating the normal character “F” is recorded, the concave portion C is interpreted as a bit “1”, and if the identification mark m2 indicating the back character of “F” is recorded, the concave portion C is interpreted. What is necessary is to interpret C as bit "0". Of course, a character string such as “the concave portion is bit“ 1 ”” may be used as the identification mark. In this case, if the character string “the concave portion is bit“ 1 ”” is described with a positive character, it is sufficient to interpret the concave portion as bit “1” literally. In other words, conversely, it is sufficient to interpret the concave portion as bit “0”.

  As described above, even when it is assumed that the medium is duplicated by the physical pressing process and the concave-convex structure of the original plate is reversed, a method of recording an identification mark having an asymmetric shape in the sub recording area Aβ is described. If it is adopted, it becomes possible to inform the operator who performs the reading operation of the correct interpretation method of the data bits.

  However, when the information is recorded as a fine physical structure pattern by performing beam exposure and patterning processing on the substrate as in the prior application, in the method of recording the identification mark having an asymmetric shape, There may be cases where the correct interpretation of data bits cannot always be conveyed. This is due to the following second reason.

  The second reason why it is not preferable to simply record the data bits such as “the concave portion is bit“ 1 ”” as it is on the medium is that beam exposure and patterning are performed using the same graphic pattern. This is because, even in this case, the physical structure actually formed on the substrate differs depending on the method of the beam exposure and the patterning treatment to be employed.

  For example, in the case of the beam exposure and patterning process illustrated in FIG. 4, the inside of a small black square (bit figure F indicating bit “1”) constituting the unit bit figure pattern P (U1) illustrated in FIG. 2 is exposed. In addition, a positive resist is used as the resist layer 20. As a result, in the information recording medium M1 shown in FIG. 4E, the bit “1” is expressed as the concave portion C, and the bit “0” is expressed as the convex portion V. However, when exposing the outside of a small black square or using a negative resist as the resist layer 20, the interpretation of the data bits for the concave portions C and the convex portions V on the generated information recording medium changes. come.

  FIG. 16 is a side cross-sectional view showing another specific process different from the exposure step and the patterning step shown in FIG. 4 (only the cut surface is shown, and the inner structure is not shown). That is, in the process shown in FIG. 16, there is no change in that the inside of the bit pattern F indicating the bit “1” is exposed, but a negative resist is used as the resist layer 20. Therefore, the exposure process shown in FIG. 16B still produces the exposed portion 21 and the non-exposed portion 22. However, when the developing process is performed, the non-exposed portion 22 is dissolved in the developing solution, and FIG. As shown in c), the exposed portion 21 remains as the remaining portion 24.

  Subsequently, when an etching process is performed, as shown in FIG. 16D, the portion of the upper surface of the layer 10 to be formed which is covered with the remaining portion 24 serving as a mask is not corroded, but is exposed. The part that is in the middle is subject to corrosion, and a recess is formed. Thus, the molded layer 10 is processed into the molded layer 13 having the uneven structure formed on the upper surface. By removing the remaining portion 24 from the molding layer 13 thus obtained, an information recording medium M3 is obtained as shown in FIG.

  Here, when comparing the information recording medium M1 shown in FIG. 4 (e) with the information recording medium M3 shown in FIG. 16 (e), it is clear that all of them are the media on which exactly the same data bit “10110” is recorded. In the former, the concave portion indicates the bit “1” and the convex portion indicates the bit “0”, whereas in the latter, the convex portion indicates the bit “1” and the concave portion indicates the bit “0”, and the data bit Is completely reversed.

  As described above, an example in which the interpretation method of the data bits for the concavo-convex structure formed on the medium is reversed depending on whether the positive resist or the negative resist is used as the resist layer 20 when performing the patterning process. As described above, when performing the beam exposure processing, the method of interpreting the data bits for the concavo-convex structure formed on the medium is also reversed depending on whether the inside of the bit figure F is exposed or the outside is exposed. Will be.

  This is because, even when the information storage medium shown in FIG. 1 is used to create the information recording medium M using exactly the same drawing data E, the conditions of the beam exposure processing in the beam exposure apparatus 200 and the conditions in the patterning apparatus 300 This means that the method of interpreting the data bits expressed by the concavo-convex structure formed on the information recording medium M finally obtained differs depending on the conditions of the patterning process.

  Therefore, as illustrated in FIG. 15A, drawing data E for recording an identification mark m1 having an asymmetric shape such as the character “F” is prepared in the sub-recording area Aβ. Even if the information recording medium M is created based on the drawing data E, it is not possible to recognize the correct data bit interpretation method using the identification mark at the time of reading. That is, as long as the same drawing data E is used, the sub-recording area is not limited to the case where it is created by the process shown in FIG. 4 (using a positive resist) or the case shown in FIG. 16 (using a negative resist). The identification mark m1 in Aβ is a regular character “F”.

  That is, when the medium M1 is formed by the process shown in FIG. 4, a medium M1 shown in FIG. 15A is obtained, and when the medium M3 is formed by the process shown in FIG. 16, the medium M3 shown in the plan view of FIG. can get. The identification mark m1 in the former sub-recording area Aβ is a regular letter “F”, and the identification mark m3 in the latter sub-recording area Aβ is also a regular letter “F”. However, in the former case, the protrusion V indicates the bit “0” and the recess C indicates the bit “1”, whereas in the latter, the protrusion V indicates the bit “1” and the recess C indicates the bit “0”. Is shown.

  On the other hand, FIG. 17B is a plan view of the medium M4 reproduced by the pressing process using the medium M3 shown in FIG. 17A as an original. Here, the identification mark m4 in the sub-recording area Aβ is the reverse letter of “F”, but the protrusion V indicates the bit “0” and the recess C indicates the bit “1”. As a result, although the medium M1 shown in FIG. 15A and the medium M4 shown in the medium 17 (b) have opposite relations of the normal characters and the back characters as the identification marks presented, the data bit interpretation method is used. Are common in that the convex portion V should be interpreted as a bit “0” and the concave portion C as a bit “1”. Similarly, the medium M2 shown in FIG. 15 (b) and the medium M3 shown in the medium 17 (a) have reverse relations of reverse characters and normal characters as the identification marks presented, but the interpretation of the data bits The method is common in that the convex portion V should be interpreted as a bit “1” and the concave portion C as a bit “0”.

  As described above, when information is recorded as a fine physical structure pattern by performing beam exposure and patterning processing on a substrate, a method of recording an identification mark having an asymmetrical shape requires a correct data bit. Can't tell how to interpret. The present invention proposes a new method for recording information indicating a method of interpreting data bits in order to address such a problem. Hereinafter, the new method will be described in detail from §7. Here, for convenience of explanation, an embodiment in which the new technique is applied to the prior application invention will be described. However, the present invention is not limited to the application to the information storage method according to the prior application invention, and is not limited to the substrate. This is a technique that can be widely applied to an information storage method of recording information as a fine physical structure pattern by performing beam exposure and patterning processing.

<<<< §7. Basic embodiment of information storage device according to the present invention >>>>>
FIG. 18 is a block diagram illustrating a basic configuration of an information storage device according to a basic embodiment of the present invention. The information storage device shown in FIG. 18 is a device including a storage processing computer 100 ′, a beam exposure device 200, and a patterning device 300, like the device shown in FIG. 1, and stores digital data D to be stored as information. It has a function of writing and storing on the recording medium M. Here, the beam exposure apparatus 200 and the patterning apparatus 300 are exactly the same components as those of the apparatus having the same reference numerals shown in FIG.

  On the other hand, the storage processing computer 100 'of the information storage device shown in FIG. 18 includes a data input unit 110, a main information pattern generation unit 170, a sub information pattern generation unit 180, and a drawing data generation unit 160'. Here, the data input unit 110 is exactly the same component as the data input unit 110 shown in FIG. 1 and plays a role of inputting digital data D to be stored.

  The main information pattern generation section 170 shown in FIG. 18 generates a main information pattern Pα indicating information of individual data bits constituting the input digital data D, and the sub information pattern generation section 180 A sub-information pattern Pβ indicating a method of interpreting the indicated data bit is generated. Then, the drawing data generating section 160 'generates drawing data E for drawing the main information pattern Pα and the sub information pattern Pβ.

  As shown in the figure, the main information pattern generation unit 170 includes a unit data generation unit 120, a unit bit matrix generation unit 130, a unit bit graphic pattern generation unit 140, and a unit recording graphic pattern generation unit 150. Each component is the same as each component indicated by the same reference numeral in FIG. Accordingly, the main information pattern Pα generated by the main information pattern generation unit 170 is, for example, an aggregate of the unit recording graphic patterns R (U1) as illustrated in FIG.

  On the other hand, the sub-information pattern Pβ generated by the sub-information pattern generation unit 180 is a pattern indicating a method of interpreting the data bits indicated by the main information pattern Pα, and is identified in FIG. 15 (a) and FIG. 17 (a). It performs the same function as the marks m1 and m3. However, as described later, the sub-information pattern Pβ used in the present invention is not constituted by a single identification mark, but is constituted by a pair of identification marks.

  The drawing data generation unit 160 ′ defines a main recording area Aα and a sub recording area Aβ on the drawing target surface, arranges the main information pattern Pα generated by the main information pattern generation unit 170 in the main recording area Aα, A composite pattern is generated by arranging the sub-information pattern Pβ generated by the sub-information pattern generation unit 180 in the recording area Aβ, and drawing data E for drawing the composite pattern is generated.

  Based on the drawing data E generated in this manner, the beam exposure apparatus 200 performs beam exposure using an electron beam or a laser beam on the substrate S serving as an information recording medium, and has a development processing unit 310 and an etching processing unit 320. The point that the patterning apparatus 300 performs the patterning process on the exposed substrate S to generate the information recording medium M on which the physical structure pattern corresponding to the drawing data E is formed is the information shown in FIG. Same as the storage device.

  That is, the beam exposure apparatus 200 performs beam exposure on the surface of the resist layer on the substrate having the layer to be formed and the resist layer covering the layer, and the development processing unit 310 The substrate is impregnated with a developing solution having a property of dissolving the part to process a part of the substrate as a remaining part, and the etching processing unit 320 performs etching on the layer to be formed using the remaining part of the resist layer as a mask. At this time, the beam exposure apparatus 200 may expose the inside of the bit figure F or may expose the outside. Further, as the resist layer, a positive resist or a negative resist may be used.

  After all, the difference between the information storage device according to the prior application shown in FIG. 1 and the information storage device according to the present invention shown in FIG. 18 is that the former storage processing computer 100 draws the main information pattern Pα. The data E is generated, whereas the latter storage processing computer 100 ′ generates the drawing data E for drawing a composite pattern in which the sub information pattern Pβ is added to the main information pattern Pα. .

  Of course, the sub-information pattern generator 180 newly added in the latter is actually a component constructed by incorporating a program into the computer, and is a component of the storage processing computer 100 'shown in FIG. A certain data input unit 110, main information pattern generation unit 170, sub-information pattern generation unit 180, and drawing data generation unit 160 'can be configured by incorporating a dedicated application program into a general-purpose computer.

  Next, the sub information pattern Pβ generated by the sub information pattern generation unit 180 will be described. Here, first, the information recording medium M5 created by executing the process shown in FIG. 4 (the process using a positive resist as the resist layer 20) by the patterning device 300 in the information storage device shown in FIG. 19, and the information recording medium M6 created by executing the process shown in FIG. 16 (process using a negative resist as the resist layer 20) is shown in the plan view of FIG. 20 (both are hatched). Is for indicating the area).

  Both the medium M5 shown in FIG. 19 and the medium M6 shown in FIG. 20 are provided on the upper surface with a main recording area Aα indicated by hatching in the figure and a sub-recording area Aβ arranged in the upper left corner of the figure. ing. Here, the main recording area Aα is an area in which a main information pattern Pα indicating information of individual data bits constituting the digital data D to be stored is recorded, for example, a unit recording as illustrated in FIG. An area in which a set of graphic patterns R (Ui) for use (i = 1, 2, 3,...) Is recorded. On the other hand, the sub recording area Aβ is an area in which the sub information pattern Pβ indicating the interpretation method of each data bit recorded as the main information pattern Pα is recorded. An area Aβ1 and a second sub recording area Aβ2 are provided.

  As described above, the medium M5 shown in FIG. 19 is created by executing the process shown in FIG. 4, and the main information pattern Pα recorded in the main recording area Aα has the bit “0” And a concave / convex structure expressing the bit “1” by the concave portion C. On the other hand, the medium M6 shown in FIG. 20 is created by executing the process shown in FIG. 16, and the main information pattern Pα recorded in the main recording area Aα has a bit “ The concave / convex structure expresses “1” and expresses the bit “0” by the concave portion C.

  As described above, both the medium M5 shown in FIG. 19 and the medium M6 shown in FIG. 20 are media created based on the same main information pattern Pα, but in the patterning process performed by the patterning device 300, The use of a type resist and the use of a negative type resist, on the other hand, result in a difference in the interpretation of the data bits. The sub-information pattern Pβ recorded in the sub-recording area Aβ always plays the role of indicating the correct interpretation method even if such a difference in the interpretation method occurs.

  In the case of the illustrated example, the sub information pattern Pβ recorded in the sub recording area Aβ is recorded in the first identification mark m10 recorded in the first sub recording area Aβ1 and in the second sub recording area Aβ2. And a second identification mark m20. Specifically, the first identification mark m10 is configured by a closed area indicating a character “convex”, the second identification mark m20 is configured by a closed area indicating a character “concave”, From the viewpoint of whether the identification mark looks brighter, it functions as a sign indicating a correct interpretation method of the data bit.

  Here, for the sake of convenience, hatching with a mesh and hatching with a dot are performed in the closed area forming the two identification marks m10 and m20 in the figure, and the hatched area with the mesh is observed brighter than the hatched area with the dot. Shall be. Therefore, in the case of the medium M5 shown in FIG. 19, the second identification mark m20 indicating the character “concave” looks brighter than the first identification mark m10 indicating the character “convex”. In the case of the medium M6 shown in FIG. 7, the first identification mark m10 indicating the character “convex” looks brighter than the second identification mark m20 indicating the character “concave” (the reason for this is that See below).

  Moreover, in the embodiment shown here, if the character “concave” looks bright, the concave portion C is set to bit “1”, and if the character “convex” looks bright, the convex portion V is set to bit “1”. An interpretation method of “1” is shown. Therefore, the reading operator holding the medium M5 shown in FIG. 19 looks at the character “concave” brighter, so that when reading the individual data bits recorded in the main recording area Aα, the reading operator It can be recognized that the interpretation method of setting the bit to “1” should be adopted, and the reading operator holding the medium M6 shown in FIG. It can be recognized that an interpretation method in which the convex portion V is set to the bit “1” when reading the individual data bits described above should be adopted.

  When a copy is created by the pressing process described above, the concave and convex structure of the copy created using the medium M5 shown in FIG. 19 as an original becomes equivalent to that of the medium M6 shown in FIG. 20, and the medium M6 shown in FIG. Since the concave-convex structure of the duplicate created as described above is equivalent to that of the medium M5 shown in FIG. 19, the information recording medium created by the information storage device according to the present invention also has “convex” and “concave” Can be recognized based on the determination of which character looks brighter.

<<<< §8. Physical structure of a pair of identification marks >>>
Next, the physical structure of the first identification mark m10 and the second identification mark m20 will be described. The pair of identification marks m10 and m20 recorded in the sub-recording area Aβ must play a role in presenting a correct data bit interpretation method to the reading operator in the above-described method. Therefore, it has a structure closely related to the data bits recorded in the main recording area Aα. Therefore, first, let us consider the characteristics of the data bits recorded in the main recording area Aα.

  As described above, the main information pattern Pα generated by the main information pattern generation unit 170 is recorded in the main recording area Aα. The main information pattern Pα is, for example, an aggregate (i = 1, 2, 3,...) Of unit recording graphic patterns R (Ui) as illustrated in FIG. Here, considering the substance of the unit recording graphic pattern R (Ui), it can be seen that the pattern has a mixture of regions having two types of attributes.

  Specifically, in the case of the example shown in FIG. 2, the unit recording graphic pattern R (U1) is a pattern in which “black areas” and “white areas” are mixed in the unit recording area Au. Of course, in practice, the unit recording graphic pattern R (U1) is represented by vector data indicating the outline of the bit graphic F and the alignment marks Q1 to Q4 as shown in the example of FIG. The inside is a “black area” and the outside is a “white area”.

  The main information pattern generation unit 170 shown in FIG. 18 generates a pattern in which areas having two types of attributes, “black area” and “white area”, are mixed as the main information pattern Pα to be recorded in the main recording area Aα. Will do. Then, the beam exposure apparatus 200 performs the beam exposure processing on one of the areas having the two types of attributes, and the patterning apparatus 300 performs the patterning processing on the exposed substrate. Will be.

  FIG. 4 shows an example in which a beam exposure process is performed on the “black region” and a patterning process is performed using a positive resist as the resist layer 20. As a result, as shown in FIG. 4E, an information recording medium M1 is obtained in which the convex portion V represents the bit "0" and the concave portion C represents the bit "1". On the other hand, if a beam exposure process is performed on the “white region” and a patterning process is performed using a positive resist as the resist layer 20, the convex portion V has the bit “1” and the concave portion C has the bit “0”. Is obtained (equivalent to the information recording medium M3 shown in FIG. 16E).

  Similarly, FIG. 16 shows an example in which beam exposure processing is performed on the “black area” and patterning processing using a negative resist as the resist layer 20 is performed. As a result, as shown in FIG. 16E, an information recording medium M3 is obtained in which the convex portion V represents the bit "1" and the concave portion C represents the bit "0". On the other hand, if a beam exposure process is performed on the “white region” and a patterning process is performed using a negative resist as the resist layer 20, the convex portion V has the bit “0” and the concave portion C has the bit “1”. Is obtained (equivalent to the information recording medium M1 shown in FIG. 4E).

  As a general theory, if one of the above-described “black area” and “white area” is called a “first attribute main area” and the other is called a “second attribute main area”, the main information pattern Pα is Predetermined points (each grid point L in the case of the example shown in FIG. 3) constituted by the first attribute main area and the second attribute main area and corresponding to each data bit are located in the first attribute main area. It is a pattern expressing binary information of each data bit depending on whether it exists or exists in the second attribute main area.

  In the case of the embodiment described here, the main information pattern generation unit 170 determines whether one of the individual bits “1” and the individual bits “0” of the digital data D to be stored (the example in FIG. 2). In this case, the bit "1") is converted into an individual bit pattern F composed of a closed area, and a main information pattern in which an area inside the bit figure F is a first attribute main area and an external area is a second attribute main area. Pα will be generated. This main information pattern Pα is recorded in the main recording area Aα shown in FIGS. 19 and 20, as described above.

  On the other hand, the sub information pattern Pβ generated by the sub information pattern generation unit 180 has a pair of identification marks m10 and m20 recorded in the sub recording area Aβ as shown in FIGS. Here, the identification mark m10 is a mark composed of “convex” characters arranged in the first sub-recording area Aβ1, and is interpreted as “the convex portion is bit“ 1 ”” (the concave portion is naturally a bit “1”). "0"). Further, the identification mark m20 is a mark composed of characters of “concave” arranged in the second sub recording area Aβ2, and is interpreted as “concave is bit“ 1 ”” (of course, convex is bit “1”). 0 ").

  As described above, the reading operator understands the interpretation method indicated by the brighter mark among the pair of identification marks m10 and m20 as the correct data bit interpretation method.

  Next, the substance of the pair of identification marks m10 and m20 will be described with reference to FIG. FIG. 21 is a plan view showing an example of the drawing pattern P (E) created by the information storage device shown in FIG. Here, the drawing pattern P (E) is obtained by synthesizing the main information pattern Pα generated by the main information pattern generation unit 170 and the sub information pattern Pβ generated by the sub information pattern generation unit 180. This is a composite pattern to be obtained. The drawing data generation unit 160 ′ generates the drawing pattern P (E) by combining the main information pattern Pα and the sub information pattern Pβ, and then draws the drawing data P (E) for drawing the drawing pattern P (E). A process for generating E is performed.

  As described above, the main information pattern Pα to be recorded in the main recording area Aα is a pattern in which areas having two types of attributes, “black area” and “white area”, are mixed. Similarly, the sub-information pattern Pβ to be recorded is a pattern in which areas having two types of attributes, “black area” and “white area”, are mixed.

  The lower part of FIG. 21 shows an enlarged view (image in a circle) of each partial region of the drawing pattern P (E) shown in the upper part of FIG. That is, the image in the lower circle p1 is an enlarged view of the partial area p1 in the first identification mark m10 arranged in the first sub recording area Aβ1 shown in the upper row, and the image in the lower circle p2 is It is an enlarged view of the partial area p2 in the second identification mark m20 arranged in the second sub recording area Aβ2 shown in the upper part, and the image in the lower circle p3 is the partial area in the main recording area Aα shown in the upper part. It is an enlarged view of p3. 21. For convenience of illustration, the dimensional ratios of the respective parts in FIG. 21 are set ignoring the actual dimensional ratios. For example, the partial areas p1 to p3 indicated by small circles in the upper part are actually Is a very small area that cannot be observed.

  The enlarged image of the partial area p3 shown in the lower part of FIG. 21 shows a pattern constituting one unit recording area Au, and a "black area" (first attribute) showing the inside of each bit figure and alignment mark. (A main area G1) and a “white area” (a second attribute main area G2) indicating an external background portion (dashed lines and dashed lines in the drawing are auxiliary lines for indicating the arrangement, and the actual pattern). Are not the lines that make up). As described above, the main information pattern Pα to be recorded in the main recording area Aα is a mixed pattern of areas having two types of attributes, “black area” and “white area”. .

  On the other hand, as can be seen from the enlarged images of the partial areas p1 and p2 shown in the lower part of FIG. 21, the sub-information pattern Pβ to be recorded in the sub-recording area Aβ is also a “black area” (first attribute sub-area g1). A mixed pattern of areas having two types of attributes, “white area” (second attribute sub-area g2). Of course, while the main information pattern Pα is a pattern indicating individual bit figures and alignment marks, the sub-information pattern Pβ is a pattern indicating a pair of identification marks m10 and m20. Is different.

  That is, the pattern in the closed region forming the identification marks m10 and m20 forms a striped pattern of “black region” and “white region” as shown in the enlarged images of the partial regions p1 and p2. . This is because a diffraction grating for visible light is formed inside the identification marks m10 and m20 when the information is recorded on the medium M as an uneven structure. As a result, a pattern is formed in which the elongated strip-shaped “black area” and the elongated strip-shaped “white area” are alternately arranged in the closed area forming the identification marks m10 and m20.

  Each grating line forming this diffraction grating is set to be in a direction parallel to the common arrangement axis Z. The illustrated example is an example in which the arrangement axis Z is set as an axis extending in the vertical direction in the figure, and therefore, a stripe pattern extending in the vertical direction is formed in the partial regions p1 and p2. Of course, the orientation of the arrangement axis Z may be set to any direction.

  The important point here is that when comparing the striped pattern in the partial area p1 with the striped pattern in the partial area p2, the width W1 of the band forming the “black area” (the first attribute sub-area g1) and “ The point is that the magnitude relationship with the width W2 of the band constituting the "white region" (second attribute sub-region g2) is reversed between the two. Specifically, in the example shown in the drawing, W1> W2 is satisfied for the partial area p1 in the identification mark m10, whereas W1 <W2 is satisfied for the partial area p2 in the identification mark m20. . The difference in the magnitude relationship between the widths causes a difference in lightness and darkness during observation, and details thereof will be described later.

  Although only the patterns in the partial areas p1 and p2 surrounded by circles are illustrated in the drawing, the partial area p1 and the partial area p1 are, of course, all over the internal closed area of the “convex” character constituting the identification mark m10. A similar pattern is formed, and a pattern similar to the partial area p2 is formed over the entire inner closed area of the “concave” character constituting the identification mark m20. In other words, the inside of the “convex” character and the inside of the “concave” character are filled with stripes extending in the vertical direction in the figure.

  In the case of the embodiment shown here, the background part (the area outside the “convex” character) in the first sub recording area Aβ1 and the background part (the area outside the “concave” character) in the second sub recording area Aβ2 ) Is configured as a “white area” (second attribute sub-area g2), but these background parts may be configured as “black areas” (first attribute sub-area g1).

  Alternatively, a striped pattern (a pattern functioning as a diffraction grating on a medium) composed of a “black area” and a “white area” may be formed on these background portions. However, since it is necessary to make the configuration such that the outline of the “convex” character and the outline of the “concave” character can be recognized when the reading operator observes, the background portion also has a striped pattern (diffraction grating). When forming a pattern, it is necessary to change the direction or pitch of the pattern (diffraction grating) inside the identification mark so that the outline of the identification mark can be recognized during observation. Therefore, in practice, it is preferable to set the background portion as a “white region” or a “black region”.

  As a result, in both the main recording area Aα and the sub recording area Aβ, a pattern in which “black area” and “white area” are mixed is arranged, and the drawing pattern P (E) becomes It is an aggregate of a large number of closed regions belonging to one of these two types. In general terms, the main information pattern Pα arranged in the main recording area Aα is a mixture of the first attribute main area G1 (eg, “black area”) and the second attribute main area G2 (eg, “white area”). The sub information pattern Pβ arranged in the sub recording area Aβ is a mixed pattern of the first attribute sub area g1 (for example, “black area”) and the second attribute sub area g2 (for example, “white area”). Will be.

  Here, if the area of “first attribute” is an area where beam exposure is performed and the area of “second attribute” is an area where beam exposure is not performed, in the case of the above example, exposure is not performed for “black area”. Therefore, no exposure is performed for the “white area”. In other words, in this case, the drawing data generation unit 160 'performs exposure on the first attribute main area G1 and the first attribute sub area g1, and performs the second attribute main area G2 and the second attribute sub area g2. , The drawing data E for not performing the exposure is generated. Of course, conversely, the area of the “second attribute” may be set as the area where the beam exposure is performed, and the area of the “first attribute” may be set as the area where the beam exposure is not performed.

  As described above, the “first attribute” depends on which attribute region is to be subjected to beam exposure during the beam exposure process, or whether a positive or negative resist is used during the patterning process. Region becomes the convex portion V or the concave portion C on the medium M (in other words, whether the region of the “second attribute” becomes the concave portion C or the convex portion V on the medium M) Will change.

  However, the important point here is that if the first attribute main region G1 becomes the convex portion V on the final medium M, the first attribute sub region g1 also becomes the convex portion V, and the first attribute main region G1 Becomes the concave portion C, the first attribute sub-region g1 also becomes the concave portion C. Of course, if the second attribute main region G2 becomes the convex portion V, the second attribute sub-region g2 also becomes the convex portion V, and if the second attribute main region G2 becomes the concave portion C, the second attribute sub-region g2 also becomes the concave portion. Become C. This is a universal method that does not change regardless of which attribute exposure is performed during the beam exposure process, regardless of whether a positive or negative resist is used during the patterning process. Matters.

  Accordingly, in the medium M created based on the drawing pattern P (E) shown in FIG. 21 and the copy created by the pressing process using the medium M as an original, the partial areas p1 to p3 are shown. Either all "black areas" will be convex portions V and all "white regions" will be concave portions C (such a medium is called "black convex medium" for convenience), or all "black regions" will be concave portions. C, and all the “white areas” become the convex portions V (such a medium is referred to as a “black concave medium” for convenience). More specifically, the medium M1 shown in FIG. 4 (e) is called a “black convex medium”, the medium M2 shown in FIG. 14 is called a “black convex medium”, and the medium M3 shown in FIG. 16 (e) is called a “black convex medium”. Will be.

  In the case of this embodiment, since the drawing pattern P (E) represents the bit “1” by the bit figure F composed of the “black area”, when performing the reading process on the “black convex medium”, The interpretation method of “the convex portion is bit“ 1 ”” may be adopted, and the reading method of “black concave medium” may be the interpretation method of “concave portion is bit“ 1 ””. Therefore, the reading operator has only to recognize whether the target medium is a “black convex medium” or a “black concave medium”. As described above, the recognition can be performed based on the criterion “which of the pair of identification marks looks brighter”.

  For example, in the case of the example shown in FIG. 21, the first identification mark m10 composed of the character “convex” and the second identification mark m20 composed of the character “concave” are compared and observed. Is bright, the medium is determined to be a “black convex medium” and the interpretation method of “the convex portion is bit“ 1 ”” may be adopted. If the “concave” character looks brighter, The medium may be determined to be a “black concave medium” and an interpretation method of “the concave portion is a bit“ 1 ”” may be adopted. Hereinafter, the reason why it is possible to determine whether the medium is a “black convex medium” or a “black concave medium” by comparing such brightness will be described.

  FIG. 22 is a diagram showing an uneven structure of a medium M5 (“black concave medium” shown in FIG. 19) created by executing the process shown in FIG. 4 based on the drawing pattern P (E) shown in FIG. It is. The upper part is a plan view of the drawing pattern P (E) shown in FIG. 21, and the lower part is an enlarged side sectional view of each part of the medium M5 corresponding to each of the partial areas p1 to p3.

  The side sectional view of the partial areas p1 and p2 shown in the lower part of FIG. 22 shows that the “black area” (first attribute sub-area g1) in the enlarged image of the partial areas p1 and p2 shown in the lower part of FIG. FIG. 22 shows a concavo-convex structure of the medium M5 in which the “region” (the second attribute sub-region g2) is a convex portion. A side sectional view of the partial region p3 shown in the lower part of FIG. Regarding the position of the second row in the bit array of 5 rows and 5 columns in the enlarged image, the “black area” (first attribute main area G1) is a concave portion, and the “white area” (second attribute main area G2) is The uneven structure of the medium M5 as a convex portion is shown. The data bits recorded in the partial area p3 must be interpreted as "bits" 1 "for concave portions and" 0 "for convex portions when reading.

  On the other hand, FIG. 23 shows an uneven structure of a medium M6 (“black convex medium” shown in FIG. 20) created by executing the process shown in FIG. 16 based on the drawing pattern P (E) shown in FIG. FIG. The upper part is a plan view of the drawing pattern P (E) shown in FIG. 21, and the lower part is an enlarged side sectional view of each part of the medium M6 corresponding to each of the partial areas p1 to p3.

  The side sectional view of the partial areas p1 and p2 shown in the lower part of FIG. 23 is such that the “black area” (first attribute sub-area g1) in the enlarged image of the partial areas p1 and p2 shown in the lower part of FIG. FIG. 23 shows a concave-convex structure of the medium M6 with the “white region” (second attribute sub-region g2) as a concave portion. A side sectional view of the partial region p3 shown in the lower part of FIG. Regarding the position of the second row in the bit array of 5 rows and 5 columns in the enlarged image, the “black area” (first attribute main area G1) is a convex portion, and the “white area” (second attribute main area G2). 3 shows a concave-convex structure of the medium M6 having a concave portion. At the time of reading, the data bits recorded in the partial area p3 must be interpreted as "a convex portion is a bit" 1 "and a concave portion is a bit" 0 ".

  Subsequently, regarding the black concave medium M5 shown in FIGS. 19 and 22, when comparing and observing the pair of identification marks m10 and m20, consider which one looks brighter. FIGS. 24A to 24C are enlarged side sectional views of the concavo-convex structure of each of the partial regions p1 to p3 of the black concave medium M5 shown in the lower part of FIG. Here, in the case where the upper surface of the dark concave medium M5 is irradiated with illumination light from an obliquely upper left direction, the behavior after the reflection of the illumination light will be described.

  First, as shown in FIG. 24A, consider the partial area p1 (that is, the internal area of the first identification mark m10). In the figure, the illumination light L1 applied to the “black area” (first attribute sub-area g1) serving as the concave portion and the “white area” (second attribute sub-area g2) serving as the convex portion are applied. An example of the behavior of each of the reflected illumination lights L2 after reflection is depicted by a dashed line. That is, the illumination light L1 incident on the concave portion collides with the side surface of the convex portion after reflection, whereas the illumination light L2 incident on the convex portion is directed upward as it is after reflection.

  Of course, even if the illumination light is incident on the concave portion, there is light that goes upward as it is after reflection, but in general, the probability that the illumination light incident on the concave portion is observed from above is low. This is because, as shown in FIGS. 4 (d) and 16 (d), in a patterning process for forming a concave-convex structure on the upper surface of the medium, a concave portion is formed by etching. This is because the side surface forms a rough corrosion surface.

  That is, in FIG. 24 (a), the bottom surface of the concave portion where the illumination light L1 is incident and the side surface of the convex portion where the reflected light is directed from the concave surface are all rough corrosion surfaces, and the corroded surface was irradiated. Light is extinguished by scattering, and the probability of being observed upward is reduced. On the other hand, the upper surface of the convex portion on which the illumination light L2 is incident is not corroded because it is protected by the resist layer. Therefore, the probability that the illumination light L2 is observed upward after being reflected by the upper surface of the convex portion is high.

  Here, in the partial area p1 shown in FIG. 24A, as shown in FIG. 21, the width W1 of the "black area" (the first attribute sub-area g1) is larger than the "white area" (the second attribute sub-area g2). ) Is larger than the width W2. Therefore, the ratio of the ratio of the incident light L1 to the concave portion (black region) that is not likely to be observed upward after reflection is higher than the ratio of the incident light L2 to the convex portion (white region) that is likely to be observed upward after reflection. And when viewed from above, it is generally darker.

  On the other hand, in the partial region p2 shown in FIG. 24B, as shown in FIG. 21, the width W1 of the "black region" (first attribute sub-region g1) is larger than the "white region" (second attribute sub-region g2). Is smaller than the width W2. Therefore, the ratio of the incident light L3 to the convex portion (white region) that is likely to be observed upward after reflection is higher than the ratio of the incident light L4 to the concave portion (black region) that is not likely to be observed upward after reflection. And when viewed from above, it is observed bright overall.

  After all, when observing the black concave medium M5 shown in FIG. 19 from above, the second identification mark m20 (partial area p2) indicating the character “concave” for the reason described with reference to FIGS. 24 (a) and 24 (b). ) Is observed brighter than the first identification mark m10 (partial region p1) indicating the character “convex”. Accordingly, the reading operator can recognize that the target medium is a “black concave medium”, and as shown in FIG. 24 (c), regarding the data bits recorded in the main recording area Aα, Correct reading processing employing the interpretation method of "1" can be performed.

  Next, with respect to the black convex medium M6 shown in FIGS. 20 and 23, when comparing and observing the pair of identification marks m10 and m20, consider which one looks brighter. FIGS. 25A to 25C are enlarged side sectional views of the concavo-convex structure of each of the partial regions p1 to p3 of the black convex medium M6 shown in the lower part of FIG. Also in this case, when the illumination light is irradiated on the upper surface of the black convex medium M6 from an obliquely upper left direction, the behavior after the reflection of the illumination light will be described.

  First, as shown in FIG. 25A, the “black region” (first attribute sub-region g1), which is a convex portion, is irradiated with respect to the partial region p1 (ie, the inner region of the first identification mark m10). Considering the behavior of the reflected illumination light L5 and the illumination light L6 applied to the “white area” (second attribute sub-area g2) serving as a concave portion, as described above, the illumination light L5 becomes Since the upper surface of the incident convex portion is not corroded, the illumination light L5 is likely to be observed upward after being reflected by the upper surface of the convex portion. On the other hand, since the concave portion where the illumination light L6 is incident is a corroded surface, the illumination light L6 is diffused on the corroded surface, and the probability of being observed upward is low.

  Here, in the partial area p1 shown in FIG. 25A, as shown in FIG. 21, the width W1 of the "black area" (first attribute sub-area g1) is larger than that of the "white area" (second attribute sub-area g2). ) Is larger than the width W2. Therefore, the ratio of the incident light L5 to the convex portion (black region) that is likely to be observed upward after reflection is higher than the ratio of the incident light L6 to the concave portion (white region) that is not likely to be observed upward after reflection. And when viewed from above, it is observed bright overall.

  On the other hand, in the partial area p2 shown in FIG. 25B, as shown in FIG. 21, the width W1 of the "black area" (the first attribute sub-area g1) is larger than the "white area" (the second attribute sub-area g2). Is smaller than the width W2. Therefore, the ratio of the incident light L7 to the concave portion (white region) that is more likely not to be observed upward after reflection is higher than the ratio of the incident light L8 to the convex portion (black region) that is more likely to be observed upward after reflection. And when viewed from above, it is observed as dark overall.

  After all, when observing the black convex medium M6 shown in FIG. 20 from above, the first identification mark m10 (partial region p1) indicating the character “convex” for the reason described with reference to FIGS. 25 (a) and 25 (b). ) Is observed brighter than the second identification mark m20 (partial region p2) indicating the character “concave”. Therefore, the reading operator can recognize that the target medium is a “black convex medium”, and as shown in FIG. 25C, the “convex convex part” of the data bits recorded in the main recording area Aα. Can be correctly read out using the interpretation method of "1".

  An advantage of the present invention is that if the drawing data E for drawing the drawing pattern P (E) as illustrated in the upper part of FIG. 21 is created by the storage processing computer 100 ', then the drawing data E No matter what kind of beam exposure processing or patterning processing is performed based on the above, by comparing the lightness and darkness of the pair of identification marks m10 and m20 formed on the final medium, the correct data bit is always obtained. The point is that an interpretation method (whether a convex portion is interpreted as a bit “1” or a concave portion is interpreted as a bit “1”) can be recognized.

  In other words, the first attribute area (areas g1 and G1) shown as “black area” in the lower part of FIG. 21 and the second attribute area (areas g2 and G2) shown as “white area” In general, one of them is a convex part and the other is a concave part. However, regardless of which one is a convex part and which is a concave part, correct data can be obtained by comparing the brightness of a pair of identification marks m10 and m20. It can recognize how to interpret the bits. This applies not only to a medium created based on the drawing data E, but also to a copy made by the pressing process using the medium as an original.

  As described above, since the striped uneven structure formed inside the identification marks m10 and m20 on the medium actually forms a diffraction grating, light observed by the reading operator is generated by the diffraction grating. That is, diffracted light. Therefore, the reading operator who has obtained the “black concave medium” shown in FIG. 19 or the “black convex medium” shown in FIG. 20 displays the “convex” character and the “concave” in the sub recording area Aβ at the upper left corner. The character "" is observed, and it is determined whether a convex portion is interpreted as a bit "1" or a concave portion is interpreted as a bit "1" depending on which character looks brighter (more clearly visible). be able to.

  Of course, when observing the “convex” and “concave” characters, the absolute brightness of these characters differs depending on the lighting environment and also depends on the direction in which the medium is held. However, since the directions of the diffraction gratings formed inside the “convex” and “concave” characters are in the same direction (direction parallel to the arrangement axis Z shown in FIG. 21), the “convex” character The phenomenon that either one looks bright has universality as long as it is compared with the character “concave”, and a correct data bit interpretation method is always presented.

  As described above, according to the present invention, when information is recorded as a fine physical structure pattern by performing beam exposure and patterning processing on a substrate, information indicating a data bit interpretation method is also recorded. It becomes possible to do.

<<<< §9. Specific form and variation of identification mark >>>
After all, the characteristics of the identification marks m10 and m20 described in §8 are summarized as follows. First, as shown in the example of FIG. 21, a band-shaped first attribute sub-region g1 extending in a direction parallel to a predetermined arrangement axis Z is provided in a closed region constituting the first identification mark m10. The band-shaped second attribute sub-regions g2 are alternately arranged in the direction orthogonal to the arrangement axis Z, and are parallel to the same arrangement axis Z in the closed region forming the second identification mark m20. The band-shaped first attribute sub-regions g1 and the band-shaped second attribute sub-regions g2 extending in different directions are alternately arranged in a direction orthogonal to the arrangement axis Z.

  Moreover, for the closed area constituting the first identification mark m10, the width W1 of the first attribute sub-area g1 is set to be wider than the width W2 of the second attribute sub-area g2, and the second identification mark m20 Is set such that the width W2 of the second attribute sub-region g2 is wider than the width W1 of the first attribute sub-region g1.

  On the other hand, the main information pattern generation unit 170 generates a main information pattern Pα in which the first attribute main area G1 and the second attribute main area G2 are mixed, as exemplified in the partial area p3 of FIG. The drawing data generation unit 160 ′ creates a combined pattern by combining the main information pattern Pα and the sub information pattern Pβ created in this way, and performs processing for generating drawing data E for drawing the combined pattern. Become.

  At this time, the drawing data generation unit 160 ′ performs exposure on the first attribute main area G1 and the first attribute sub area g1, and performs exposure on the second attribute main area G2 and the second attribute sub area g2. Exposure is performed on the drawing data E or the second attribute main area G2 and the second attribute sub-area g2 to prevent the first attribute main area G1 and the first attribute sub-area g1 from being performed. And the width of the first attribute sub-region g1 and the second attribute sub-region g2 is set to a dimension capable of forming a diffraction grating for visible light. To set.

  The upper part of FIG. 21 shows an example of a drawing pattern P (E) for drawing on a medium, and the lower part shows an enlarged view of the partial regions p1 to p3. Inside the identification marks m10 and m20, as shown as partial regions p1 and p2, a band-shaped “black region” (first attribute sub-region g1) and a band-shaped “white region” (second attribute sub-region) g2) are formed alternately. As described above, on the medium, this striped pattern is formed as a concavo-convex structure functioning as a diffraction grating, and the reading operator makes the pair of identification marks m10 as a “convex” character and a “concave” character that shine. , M20.

  Therefore, the width W1 of the “black region” (first attribute sub-region g1) and the width W2 of the “white region” (second attribute sub-region g2) formed on the actual medium are determined by the diffraction grating for visible light. It is necessary to set the width to be set.

  On the other hand, the difference between the width W1 and the width W2 causes a difference in brightness between the two identification marks m10 and m20 when compared and observed, so that the function as the diffraction grating is not impaired in practical use. It is preferable to set as large as possible. The inventor of the present application performed an experiment in which various dimensions were set as the width W1 and the width W2 to create an actual medium. When the ratio between the width W1 and the width W2 was set to be 5 times or more, It was found that the contrast difference between the two identification marks m10 and m20 can be remarkably recognized regardless of the lighting environment and the observation environment.

  Therefore, in practice, the sub-information pattern generation unit 180 determines that the width W1 of the first attribute sub-region g1 is five times the width W2 of the second attribute sub-region g2 for the closed region forming the first identification mark m10. This is set so that the width W2 of the second attribute sub-region g2 is at least five times the width W1 of the first attribute sub-region g1 for the closed region constituting the second identification mark m20. (In the example shown in FIG. 21, the dimensional ratio does not satisfy such a condition for convenience of illustration.)

  In addition, in order to make the brightness of the “convex” character when observing the “black convex medium” and the brightness of the “concave” character when observing the “black concave medium” as similar as possible. The sub-information pattern generation unit 180 determines that the width W1 of the first attribute sub-region g1 in the closed region constituting the first identification mark m10 and the second attribute sub-region in the closed region constituting the second identification mark m20. The width W2 of the region g2 is set to be equal, and the second attribute in the closed region constituting the first identification mark m10 is the width W2 of the sub-region g2 and the first attribute in the closed region constituting the second identification mark m20. It is preferable to set the width W1 of the sub-region g1 to be equal.

  In other words, in the example shown in FIG. 21, the width W1 of the black region g1 in the partial region p1 is equal to the width W2 of the white region g2 in the partial region p2, and the width of the white region g2 in the partial region p1. What is necessary is just to set so that W2 and width W1 of black area g1 in partial area p2 become equal. If such settings are made, the “black convex medium” and the “black concave medium” created based on the drawing pattern P (E) shown in FIG. Observing in the direction of “), the brightness of the“ convex ”character on the“ black-convex medium ”and the brightness of the“ concave ”character on the“ black-concave medium ”are equal, creating a uniform medium. Will be possible.

  Here, for reference, a dimension value of each part of the identification mark for which a good observation result is obtained by an experiment performed by the inventor of the present application is described as an example. First, in the partial area p1 shown in FIG. 21 (that is, in the first identification mark m10), the width W1 of the first attribute sub-area g1 is 1.8 μm, and the width W2 of the second attribute sub-area g2 = 0. It was 2 μm. On the other hand, in the partial region p2 (that is, in the second identification mark m20), the width W1 of the first attribute sub-region g1 was set to 0.2 μm, and the width W2 of the second attribute sub-region g2 was set to 1.8 μm. In any case, the length in the longitudinal direction of each band-shaped region is a size obtained by extending both ends thereof until reaching the outline of each identification mark.

  When the above dimensions are adopted, the grating line pitch of the diffraction grating eventually becomes 2 μm, which is a dimension that causes a sufficient diffraction phenomenon with respect to visible light. In the above embodiment, each bit figure F recorded in the main recording area Aα is a square having a side of 0.1 μm, and the step of the concave-convex structure formed on the medium is set to 0.2 μm.

  It is preferable that the first identification mark m10 and the second identification mark m20 formed on the information recording medium have a size that can be visually observed. Of course, even a small mark that is difficult to observe with the naked eye can be observed using a magnifying glass or the like. However, in practice, a reading operator holding a medium reads the medium as a “black convex medium”. It is preferable to be able to immediately recognize whether the mark is a black-and-white medium by visually observing the mark. Therefore, the sub-information pattern generation unit 180 generates a sub-information pattern in which the first identification mark m10 and the second identification mark m20 formed on the information recording medium have a size that can be visually observed. Is preferred. In the above embodiment, each of the identification marks m10 and m20 is set to have a size of about 3 mm in length and width on the medium.

  Next, some variations of the identification mark used in the present invention will be described. FIG. 26 is a plan view showing the configuration and arrangement of the identification marks in the basic embodiment described so far. Actually, the drawing pattern P (E) is composed of a main information pattern Pα recorded in the main recording area Aα and a sub information pattern Pβ recorded in the sub recording area Aβ. Only the pattern Pβ is shown. The sub-information pattern Pβ is a pattern having a first identification mark m10 indicating a “convex” character and a first identification mark m20 indicating a “concave” character. The interpretation method of the data bits recorded in the main recording area Aα is recognized depending on which of the marks looks bright.

  In practicing the present invention, the positions of the first identification mark m10 and the second identification mark m20 on the medium are not particularly limited. Therefore, for example, the first identification mark m10 may be arranged at the upper left corner of the medium, and the second identification mark m20 may be arranged at the lower right corner. However, in practice, it is not preferable to arrange these two identification marks apart from each other. This is because the reading operator needs to compare and observe the two identification marks m10 and m20 and compare the brightness. In order to compare the brightness by comparing and observing the two identification marks, it is preferable to arrange the two adjacently.

  As in the example shown in FIG. 26, if the letters “convex” and “concave” are arranged right and left next to each other, the reading operator can easily compare the brightness. Therefore, in practical use, it is preferable that the sub-information pattern generation unit 180 generate the sub-information pattern Pβ in which the first identification mark m10 and the second identification mark m20 are arranged adjacent to each other.

  Further, in order to further facilitate comparison observation, it is also possible to generate a sub-information pattern Pβ in which the closed region forming the first identification mark and the closed region forming the second identification mark are in contact with each other. is there. FIG. 27A shows an example in which a “convex” character and a “concave” character are arranged vertically adjacent to each other, and are arranged so that the respective closed regions are in contact with each other. Since the closed area forming the first identification mark m11 and the closed area forming the second identification mark m21 are in contact with each other across the boundary line, the reading operator further compares the brightness of the two. It can be done easily. In the case of the illustrated example, the first identification mark m11 is a “convex” character, and the second identification mark m21 is a “concave” character. By inverting the top and bottom and fitting it on the upper part of the "convex" character, the identification mark that is integrated as a whole has been successfully formed.

  On the other hand, FIG. 27B shows an example in which a “concave” character is arranged so as to be embedded inside a “convex” character. Since the “concave” character is in contact with the “convex” character with its contour line as a boundary, the reading operator can more easily compare the brightness of the two. As described above, the sub-information pattern Pβ in which the second identification mark m22 is embedded inside the first identification mark m12 may be generated. On the contrary, the first information mark P22 may be generated inside the second identification mark m22. The sub-information pattern Pβ in which the identification mark m12 is embedded may be generated. In any case, since the external identification mark comes into contact with the entire contour of the identification mark embedded therein as a boundary, an effect of facilitating comparison observation can be obtained.

  In the embodiments described so far, a mark designed with a “convex” character is used as a first identification mark, and a mark designed with a “concave” character is used as a second identification mark. Of course, the identification marks used in practicing the present invention are not limited to marks using these characters. The first identification mark is a mark indicating the first interpretation method for the data bits recorded in the main recording area Aα, and the second identification mark is a mark indicating the second interpretation method. Any mark can be used as long as the person can recognize either interpretation method based on these identification marks.

  For example, the character “A” may be used as the first identification mark, and the character “O” may be used as the second identification mark. In this case, for example, in a medium in which the character “A” looks bright, the convex portion is interpreted as a bit “1”, and in a concave portion, the medium is interpreted as bit “0”. If an agreement is made to interpret "0" and the concave portion as a bit "1", and the agreement is transmitted to the reading operator, the reading operator can make the brightness of the character "A / Otsu" clear. With this determination, it is possible to recognize a correct data bit interpretation method.

  Of course, the identification mark does not necessarily need to be a character, but may be a mark such as a number, a symbol, or a figure. In addition, each identification mark does not necessarily need to be constituted by a single closed area, and may be constituted by a plurality of closed areas. FIG. 28A is a plan view showing an example of an identification mark formed by a figure. Moreover, in this example, each identification mark is constituted by a plurality of closed areas.

  That is, the first identification mark m13 shown on the left side of FIG. 28A is a mark formed by combining two sets of closed areas m13a and m13b each formed of a triangle, and is a design reminiscent of a “convex” character. It has become. On the other hand, the second identification mark m23 shown on the right side of FIG. 28B is a mark formed by combining three sets of closed areas m23a, m23b, and m23c each having a rectangular shape, and is a “concave” mark. It has a design reminiscent of letters.

  Even when each of the identification marks is constituted by a plurality of closed areas in this manner, a stripe pattern as illustrated in the partial area p1 of FIG. 21 is formed in the closed areas m13a and m13b, and the closed areas m23a, m23b, and m23c are formed. If a stripe pattern as illustrated in the partial area p2 of FIG. 21 is formed in the inside, the first identification mark m13 is recognized as one mark as a whole, and the second identification mark m23 is also Is recognized as one mark, and a correct data bit interpretation method can be recognized by comparing the brightness of both.

  In addition, the identification mark does not necessarily need to be configured by a single character, a number, a symbol, or a graphic, and may be configured by a combination of these. For example, if an identification mark is formed by a combination of a plurality of characters, a sentence can be formed by the identification mark. FIG. 28B shows an example of an identification mark constituting such a sentence. More specifically, in the case of the example shown in FIG. 28B, a sentence consisting of a character string “a convex portion is bit“ 1 ”” forms the first identification mark m14, and “a concave portion is a bit”. A sentence consisting of a character string “1” is a second identification mark m24.

  FIG. 29 is a plan view of the drawing pattern P (E) having the identification marks m14 and m24 according to the modification shown in FIG. In the case of this example, a sentence is recorded in two sub-rows in a sub-recording area Aβ provided in the upper left corner of the drawing pattern P (E). The upper sentence is a first identification mark m14 of “a convex portion is bit“ 1 ””, and the lower sentence is a second identification mark m24 of “a concave portion is bit“ 1 ”.” . Of course, a stripe pattern as illustrated in the partial area p1 of FIG. 21 is formed inside each character of the upper sentence constituting the first identification mark m14, and the lower row constituting the second identification mark m24. Inside each character of the text, a striped pattern as illustrated in the partial area p2 of FIG. 21 is formed.

  Therefore, if the medium created based on the drawing pattern P (E) is a “black convex medium”, the first identification mark m14 will be observed brighter, and the “black concave medium” will be observed. If so, the second identification mark m24 is observed brighter. After all, the reading operator observes the sub-recording area Aβ of the hand-held medium, and if the sentence “the convex portion is bit“ 1 ”” looks bright, it is recorded in the main recording area Aα. For the data bits, the read process of interpreting the convex portion as bit “1” may be performed, and if the text “the concave portion is bit“ 1 ”” looks bright, the concave portion is interpreted as bit “1”. What is necessary is just to carry out the reading process. FIG. 29 shows the latter observation mode.

  In short, the sub-information pattern Pβ used in the present invention is the first information (one of the two data bit interpretation methods) consisting of characters, numbers, symbols, figures, a part thereof, or a combination thereof. (Indicating information), a first identification mark having one or a plurality of closed areas, and second information (characters, numerals, symbols, graphics, a part thereof, or a combination thereof) composed of a character, a numeral, a symbol, a graphic, or a combination thereof Any pattern may be used as long as it has a second identification mark having one or more closed areas for presenting information indicating the other of the interpretation methods).

  Finally, another variation of the identification mark forming the sub-information pattern will be described with reference to FIG. FIG. 30 is a plan view showing a modification in which an auxiliary common identification mark is further used as a sub information pattern in addition to the first identification mark and the second identification mark.

  The sub information pattern shown in the upper part of FIG. 30 is configured by a total of four sets of rectangles arranged in two rows above and below. That is, a square central rectangle m15 is arranged in the center of the upper row, a square left rectangle m25a is arranged on the left, and a square right rectangle m25b is arranged on the right. In the lower row, a rectangular lower rectangle m30 having a horizontal width corresponding to the total width of the three groups of rectangles is arranged. In other words, three rectangles, a left rectangle m25a, a center rectangle m15, and a right rectangle m25b, are arranged laterally adjacent to each other such that they are left, center, and right, respectively. A figure in which the lower rectangle m30 is arranged so as to be adjacent in common is shown.

  Here, the center rectangle m15 constitutes a first identification mark, and a combination of the left rectangle m25a and the right rectangle m25b constitutes a second identification mark. The feature of this variation is that a lower rectangle m30 constituting the auxiliary common identification mark is further provided. The auxiliary common identification mark m30 is what should be called a third identification mark, and has optical characteristics different from those of the first identification mark and the second identification mark.

  The lower part of FIG. 30 shows an enlarged view (image within a circle) of each partial area of the sub-information pattern shown in the upper part of FIG. That is, the image in the lower circle p1 is an enlarged view of the partial area p1 in the central rectangle m15 constituting the first identification mark shown in the upper row, and the image in the lower circle p2 is the second picture shown in the upper row. 5 is an enlarged view of a partial area p2 in the left rectangle m25a constituting the identification mark (the same is true for an enlarged view of the partial area in the right rectangle m25b), and the image in the lower circle p3 is the auxiliary common identification mark shown in the upper row. 31 is an enlarged view of a partial area p3 in the lower rectangle m30 constituting (the dimensional ratio of each part is set ignoring the actual dimensional ratio also in FIG. 30).

  Inside the partial areas p1, p2, and p3 shown in the lower part of FIG. 30, elongated black "black areas" and elongated white "white areas" are alternately arranged as in the example described above. Thus, on the medium M, it functions as a diffraction grating for visible light. As in the embodiment described with reference to FIG. 21, each of the grating lines forming these diffraction gratings is set to be in a direction parallel to the common arrangement axis Z. The illustrated example is an example in which the arrangement axis Z is set as an axis extending in the vertical direction in the figure, and therefore, a stripe pattern extending in the vertical direction is formed in the partial regions p1, p2, and p3. Of course, the orientation of the arrangement axis Z may be set to any direction.

  The enlarged view of the partial areas p1 and p2 shown in FIG. 30 is exactly the same as the enlarged view of the partial areas p1 and p2 shown in FIG. That is, when the stripe pattern in the partial area p1 forming the first identification mark is compared with the stripe pattern in the partial area p2 forming the second identification mark, a “black area” (first attribute sub-area g1) is obtained. Is smaller than the width W1 of the band constituting the “white area” (second attribute sub-area g2). Specifically, in the example shown in the drawing, W1> W2 is satisfied for the partial region p1, whereas W1 <W2 is satisfied for the partial region p2. As described above, the difference in the magnitude relationship between the widths causes the difference in lightness and darkness during observation.

  On the other hand, with respect to the striped pattern in the partial area p3 forming the auxiliary common identification mark, in this embodiment, the width W1 of the band forming the “black area” (the first attribute sub-area g1) and the “white area” ( The width W2 of the band constituting the second attribute sub-region g2) is set to be equal. As a result, W1> W2 is set for the first identification mark, W1 <W2 is set for the second identification mark, and W1 = W2 is set for the auxiliary common identification mark.

  As described above, even when the information recording medium M is generated using the drawing data having the same sub-information pattern as illustrated in FIG. 30, the black area is convex due to the difference in the beam exposure and the patterning processing. It is different whether it is a certain “black convex medium” or a “black concave medium” in which the black area is concave. Therefore, in the case of the information recording medium M created by the information storage device according to the present invention, by observing this sub-information pattern, the first black area (first attribute sub-area g1) occupies a larger area. Is determined to be a “black convex medium” when the identification mark looks bright, and when the second identification mark occupying a larger area of the “white area” (second attribute sub-area g2) looks bright, The point that can be determined as a “black concave medium” is as described above.

  The important point of the embodiment shown in FIG. 30 is that the first identification mark m15 and the second identification mark at the time of observation depend on whether the actual medium M is a “black convex medium” or a “black concave medium”. Although the light / dark relationship with m25 (m25a and m25b) is reversed, the brightness of the auxiliary common identification mark m30 is always the brightness of the first identification mark m15 and the brightness of the second identification mark m25. It is an intermediate point. In particular, in the case of the embodiment shown in FIG. 30, since the setting of W1 = W2 is made for the auxiliary common identification mark m30, the actual medium M depends on whether the medium is a “black convex medium” or a “black concave medium”. There is no difference in the brightness of the auxiliary common identification mark m30.

  The role of the auxiliary common identification mark m30 is that, in the case of a “black convex medium” in which the first identification mark m15 is observed brighter than the second identification mark m25, the auxiliary identification mark m30 is simultaneously observed with the first identification mark m15. , To constitute a first mark indicating that the medium is a “black convex medium”, and the “black concave medium” in which the second identification mark m25 is observed brighter than the first identification mark m15. In the case of "medium", a second mark indicating that the medium is a "black concave medium" is formed by simultaneous observation with the second identification mark m25.

  Such a role will be described with reference to a specific embodiment of FIG. FIG. 31 is a plan view showing an observation mode of each identification mark in the modification shown in FIG. In FIG. 31, three types of hatching are applied to each area. The hatched area by the mesh is observed bright, the hatched area by the dot is observed dark, and the hatched area by the diagonal line has an intermediate brightness. Indicates that it is observed.

  FIG. 31 (a) shows the observation mode of the “black convex medium”, in which the first identification mark m15 is bright, the second identification mark m25 is dark, and the auxiliary common identification mark m30 has intermediate brightness. To be observed. Therefore, the observer's eyes recognize the bright first identification mark m15 and the auxiliary common identification mark m30 of intermediate brightness as one fused mark. Specifically, the observer grasps the first mark indicating the character “convex” as shown by a thick frame in the figure and recognizes the medium M as a “black convex medium”. it can. In other words, this sub-information pattern indicates a method of interpreting that “the convex portion is bit“ 1 ””.

  On the other hand, FIG. 31B shows an observation mode of the “black concave medium”, in which the second identification mark m25 is bright, the first identification mark m15 is dark, and the auxiliary common identification mark m30 is medium bright. Observed by Therefore, the observer's eyes recognize the bright second identification mark m25 and the auxiliary common identification mark m30 of intermediate brightness as one fused mark. Specifically, the observer grasps the second mark indicating the character “concave” as shown by a thick frame in the figure, and recognizes the medium M as a “black concave medium”. it can. In other words, this sub-information pattern indicates an interpretation method that “the concave portion is bit“ 1 ””.

  After all, when the variation illustrated in FIG. 30 is implemented, the sub-information pattern generation unit 180 includes, in addition to the first identification mark m15 and the second identification mark m25, a sub-information having an auxiliary common identification mark m30. What is necessary is just to have the function of generating a pattern. Here, the auxiliary common identification mark m30 is an identification mark having one or a plurality of closed areas for presenting auxiliary common information composed of characters, numbers, symbols, graphics, or a part thereof, or a combination thereof. I just need.

  The important point here is that, within the closed area constituting the auxiliary common identification mark m30, as shown as a partial area p3 in FIG. 30, the arrangement axis Z (in the case of the illustrated example, the vertical axis in the figure) The band-shaped first attribute sub-regions g1 and the band-shaped second attribute sub-regions g2 extending in the parallel direction are alternately arranged in a direction orthogonal to the arrangement axis Z (in the example shown, the left-right direction). That is, on the actual medium M, a diffraction grating for visible light is formed.

  In the case of the embodiment shown in FIG. 30, the width W1 of the first attribute sub-region g1 and the width W2 of the second attribute sub-region g2 in the auxiliary common identification mark m30 are set to be equal. As described above, this is a consideration for preventing a difference in the brightness of the auxiliary common identification mark m30 from occurring depending on whether the actual medium M is a “black convex medium” or a “black concave medium”. However, in the auxiliary common identification mark m30, it is not always necessary to set W1 = W2, and a slight difference may occur between the two.

  The important point is that the difference between the width W1 of the first attribute sub-region g1 and the width W2 of the second attribute sub-region g2 in the auxiliary common identification mark m30 is the same as the difference between the first identification mark m15 and the second identification mark m25. The point is that the difference is set to be smaller than the difference between the width W1 of the one attribute sub-region g1 and the width W2 of the second attribute sub-region g2. With such a setting, the brightness of the auxiliary common identification mark m30 is equal to the brightness of the first identification mark m15, regardless of whether the actual medium M is a “black convex medium” or a “black concave medium”. And the brightness of the second identification mark m25, the brightness can be observed as an intermediate brightness, so that any medium can serve as an auxiliary mark commonly observed.

  A feature of the embodiment shown in FIG. 30 is that a first mark (indicating a first interpretation method of data bits indicated by a main information pattern) is provided by a combination of a first identification mark m15 and an auxiliary common identification mark m30. And a combination of the second identification mark m25 and the auxiliary common identification mark m30, the second identification mark indicating the second interpretation method of the data bit indicated by the main information pattern. This is a point where a mark (a mark indicating the character “concave”) is formed. That is, a sub-information pattern is formed by four sets of rectangles shown in the upper part of FIG. 30, a first identification mark is formed by a central rectangle m15, a second identification mark is formed by a left rectangle m25a and a right rectangle m25b, and an auxiliary common pattern is formed by a lower rectangle m30. Since the identification marks are respectively formed, the first mark indicating the character “convex” and the second mark indicating the character “concave” can be displayed.

  Of course, theoretically, the first identification mark (mark consisting of a single square) composed of the central rectangle m15 can be observed brightly without providing the auxiliary common identification mark m30, or the left rectangle m25a and the right rectangle m25a can be observed. The method of interpreting the data bits can be indicated depending on whether the second identification mark (a mark formed of a pair of squares) composed of the rectangle m25b can be observed brightly. However, as shown in FIG. 31, if the auxiliary common identification mark m30 is added, the first mark indicating the character “convex” and the second mark indicating the character “concave” can be displayed. The information pattern becomes a mark directly indicating whether the “bit“ 1 ”” is a convex portion or a concave portion, so that the observer can more intuitively recognize the data bit interpretation method.

  It is not always necessary to use the characters “convex” and “concave” as the first mark and the second mark. For example, in FIG. 28 (b), a first identification mark m14 of “a convex portion is bit“ 1 ”” and a second identification mark m24 of “a concave portion is bit“ 1 ”” are used. Although the above embodiment is shown, it is also possible to use the auxiliary common identification mark described above in this embodiment. More specifically, for example, the portion of “the convex portion” is the first identification mark, the portion of the “recess portion” is the second identification mark, and the portion of “bit“ 1 ”” is the auxiliary common identification. Can be a mark.

<<<< §10. Variations in the structure of the information recording medium >>>
In §2, several variations of the structure of the information recording medium created by the information storage device according to the invention of the prior application are described with reference to FIG. Here, variations of the structure of the information recording medium created by the information storage device according to the present invention will be described.

  In the case of the embodiments described in §7 and §8, the patterning device 300 causes the first attribute area (the first attribute main area G1 and the first attribute sub area g1) and the second attribute area (the second attribute main area). A physical structure having a concavo-convex structure including a concave portion C indicating one of G2 and the second attribute sub-region g2) and a convex portion V indicating the other is formed. On the other hand, FIG. 5C shows, as a variation of the invention of the prior application, a modified example in which the additional layer 32 is formed on the surface of the convex portion V in the physical structure having such an uneven structure. Thus, the modification in which the additional layer is formed on the surface of the convex portion V is also effective in the present invention.

  32 to 35 are side sectional views showing various variations of the information recording medium on which information has been written by the information storage device shown in FIG. 18, and FIG. The lower section (b) shows a side section of the partial area p2 on which the second identification mark m20 is recorded. Is not shown).

  The feature of the modification shown in FIG. 32 is that an additional layer 61 is further provided on the surface of the convex portion of the substrate 60 after the processing for forming the uneven structure on the upper surface. Here, a layer made of a light reflective material is used as the additional layer 61. In order to create a physical structure as shown in FIG. 32, the patterning apparatus 300 may be provided with a function of forming an additional layer 61 made of a light-reflective material on the surface of the convex portion of the layer 60 to be molded. Good.

  As described above, when the additional layer 61 made of a light-reflective material is formed on the surface of the convex portion, when the first identification mark m10 and the second identification mark m20 are compared, the brightness of both is reduced. The difference can be made more remarkable, and an effect of facilitating observation by the reading operator can be obtained. FIGS. 32 (a) and 32 (b) show the structure of the “black concave medium” as in the case of the medium M5 shown in FIG. 24. The light beam L9 incident on the convex portion is reflected upward and observed. Most of the light beam L10 incident on the concave portion is scattered and disappears. Therefore, the first identification mark m10 (FIG. 32A) in which the occupied area of the concave portion is larger than the occupied area of the convex portion looks dark, and the occupied area of the convex portion is larger than the occupied area of the concave portion. The second identification mark m20 (FIG. 32 (b)) looks bright.

  At this time, if the additional layer 61 made of a light-reflective material is formed on the surface of the convex portion, the reflectance of the light beam L9 incident on the convex portion can be improved, so that the second identification mark m20 (FIG. 32 (b)) can be made brighter. Therefore, comparison observation by the reading operator can be made easier.

  In the case of a medium employing the structure according to the modification shown in FIG. 32, the width of the first attribute sub-region g1 (recess) in the partial region p1 (FIG. 32 (a)) is W1 = 19 μm, and the second attribute sub-region g1 is The width of the region g2 (convex portion) is W2 = 1 μm, the width of the first attribute sub-region g1 (concave portion) in the partial region p2 (FIG. 32 (b)) is W1 = 1 μm, and the width of the second attribute sub-region g2 (convex portion) ) Was set such that the width of W2 was 19 μm and the grid line pitch was 20 μm, and when observed from above, both identification marks m10 and m20 could be confirmed in good condition by reflected diffraction light. .

  On the other hand, in a modification shown in FIG. 33, the patterning apparatus 300 performs a patterning process on a substrate 65 made of a light-transmitting material, thereby forming a concavo-convex structure on the surface (the upper surface in the drawing) of the substrate 65. Further, in this example, an additional layer 66 made of a light-shielding material is formed on the back surface (the lower surface in the figure) of the substrate 65. In the case of the medium composed of the substrate 65, the point of recognizing each identification mark by observing the reflected light of the illumination light irradiated from above is still the same, but the substrate 65 is made of a translucent material. Therefore, if the illumination light L11 from the rear surface is transmitted upward, it may adversely affect the observation of the identification mark.

  In the structure shown in FIG. 33, the additional layer 66 made of a light-shielding material formed on the back surface of the substrate 65 allows the illumination light L11 from such a back surface to pass upward and adversely affect the observation of the identification mark. Performs a function that prevents things. When the substrate 65 is made of a non-light-transmitting material, it is not necessary to provide the additional layer 66 on the back surface. However, when the substrate 65 is made of a light-transmitting material, the light-shielding It is preferable to provide an additional layer 66 made of a material.

  In each of the embodiments described so far, each of the identification marks is observed by observing from above the reflected light on the upper surface of the illumination light irradiated from above for the medium having the uneven structure formed on the upper surface. However, in the case of a medium using a substrate 65 made of a translucent material, as shown in an example shown in FIG. 34, the transmitted light from the upper surface of the illumination light applied to the lower surface from below is transmitted upward. It is also possible to recognize each identification mark by observing from.

  In FIG. 34, light rays L12 and L13 transmitted from below to above the light-transmitting substrate 65 are drawn by alternate long and short dash lines. The light ray L12 is light that passes through the convex portion V and goes upward. , The light beam L13 is light that passes through the concave portion C and travels upward. Theoretically, unless the substrate 65 is a completely transparent material having 100% translucency, a part of the transmitted light is attenuated while traveling through the substrate 65, so that when viewed from above, the projected portion V Is slightly lower than the intensity of the light beam L13 transmitted through the concave portion C. Therefore, in the case of the illustrated example, the first identification mark m10 (FIG. 34A) in which the occupied area of the concave portion C is larger than the occupied area of the convex portion V looks slightly brighter, and the occupied area of the convex portion V The second identification mark m20 (FIG. 34B), which is larger than the area occupied by the concave portion C, looks slightly darker.

  However, in the case of the configuration shown in FIG. 34, since the difference between the brightness of the two identification marks observed by the transmitted light is very small, the function as the identification mark according to the present invention is not sufficient in practical use. Can not. Therefore, in practice, it is preferable to form an additional layer 67 made of a light-shielding material on the upper surface of the convex portion of the substrate 65 as in the example shown in FIG. In order to form a medium having the structure shown in FIG. 35, the patterning device 300 performs a patterning process on the substrate 65 made of a light-transmitting material, thereby forming an uneven structure on the upper surface thereof. What is necessary is just to perform the process which forms the additional layer 67 which consists of a light-shielding material on the surface of the convex part V.

  In the case of the medium shown in FIG. 35, the light beam L13 that is going to pass through the concave portion C is transmitted upward and is observed as it is, but the light beam L12 that is going to pass through the convex portion V is a light-shielding material. Is not obstructed by the additional layer 67 made of Therefore, in the case of the illustrated example, the first identification mark m10 (FIG. 35 (a)) in which the occupied area of the concave portion C is larger than the occupied area of the convex portion V looks bright, and the occupied area of the convex portion V is bright. The second identification mark m20 (FIG. 35 (b)), which is wider than the area occupied by the concave portion C, looks dark. By forming the additional layer 67 made of a light-shielding material, the difference in brightness between the two identification marks becomes remarkable, and the function as the identification mark according to the present invention can be sufficiently achieved.

  Also, in the case of the medium employing the structure according to the modification shown in FIG. 35, the width of the first attribute sub-region g1 (recess) in the partial region p1 (FIG. 35 (a)) is W1 = 19 μm, and the second attribute The width of the sub-region g2 (projection) is W2 = 1 μm, the width of the first attribute sub-region g1 (recess) in the partial region p2 (FIG. 35B) is W1 = 1 μm, and the width of the second attribute sub-region g2 (convex) is Is set such that the grid line pitch is 20 μm with the width of the portion (W2) = 19 μm, and when observed from above, both identification marks m10 and m20 can be confirmed in a good state by transmitted diffraction light. Was.

  As described above, several variations of the structure have been described for the information recording medium having the uneven structure formed on the surface of the substrate. However, in practicing the present invention, the physical structure indicating the bit information is not necessarily limited to the uneven structure. Instead, it is also possible to adopt a mesh structure as illustrated in FIG. 5A as a modification of the invention of the prior application. In this case, the patterning apparatus 300 determines whether the first attribute area (first attribute main area G1 and first attribute sub area g1) and the second attribute area (second attribute main area G2 and second attribute sub area g2) are to be used. What is necessary is just to form the network structure which consists of the through-hole H which shows any one, and the non-hole part N which shows the other.

  In this case, each data bit of the digital data to be stored includes a through-hole H indicating one of the bit “1” and the bit “0” and a non-hole N indicating the other in the main recording area Pα. It will be recorded as a reticulated structure. For example, in the network structure 12 shown in FIG. 5A, a position indicated by a thick dashed line (a position corresponding to a grid point L for recording a bit) is a through hole H or a non-hole N (a through hole). The bit “1” and the bit “0” are represented as shown in FIG.

  On the other hand, information indicating the interpretation method of the data bits is recorded in the sub recording area Pβ as information of a pair of identification marks.

  36 to 39 are side sectional views each showing an information recording medium having a net-like structure created by the information storage device shown in FIG. In each case, the upper drawing (a) shows a side cross section of the partial area p1 where the first identification mark m10 is recorded, and the lower drawing (b) shows the partial area p2 where the second identification mark m20 is recorded. The side cross section is shown (in each case, only the cut surface is shown, and the illustration of the inner structure is omitted).

  FIG. 36 shows a side cross section of the partial regions p1 and p2 in the information recording medium constituted by the substrate 70 formed of a network structure in which no additional layer is formed. Here, first, let us consider a case in which each identification mark is observed by observing from above the reflected light on the upper surface of the illumination light irradiated from above on this information recording medium. In this case, the light beam L14 that has entered the non-hole portion N is reflected on the upper surface of the non-hole portion N and is observed upward. On the other hand, the light beam L15 incident on the through hole H is transmitted below the medium as shown in the drawing, or collides with the side surface of the through hole H and is scattered.

  Therefore, the first identification mark m10 (FIG. 36 (a)) in which the occupied area of the through-hole H is larger than the occupied area of the non-hole N looks dark, and the occupied area of the non-hole N is penetrating. The second identification mark m20 (FIG. 36B), which is wider than the area occupied by the hole H, looks bright. Here, a mark indicating the interpretation method of “the non-hole portion N is the bit“ 1 ”” is used as the identification mark m10, and a mark indicating the interpretation method of “the through hole H is the bit“ 1 ”” is used as the identification mark m20. If used, each of the identification marks m10 and m20 functions normally as a mark indicating a method of interpreting data bits.

  That is, in the case of the example shown in FIG. 36, the second identification mark m20 looks brighter, so the interpretation method of “the through hole H is the bit“ 1 ”” is adopted. It shows the correct interpretation of the data bits shown in FIG.

  On the other hand, in the modification shown in FIG. 37, an additional layer 71 is further provided on the upper surface of the substrate 70 made of the network structure shown in FIG. Here, as the additional layer 71, a layer made of a light reflective material is used. In order to form a physical structure as shown in FIG. 37, the patterning device 300 applies a light-reflecting property to one surface (the upper surface in the case of the illustrated example) of the non-hole portion N of the substrate 70 made of a network structure. A function of forming an additional layer made of a material may be provided.

  As described above, when the additional layer 71 made of a light-reflective material is formed on the upper surface of the non-hole portion N, when the first identification mark m10 and the second identification mark m20 are compared with each other, the brightness of both is increased. The difference can be made more remarkable, and the effect of facilitating the observation by the reading operator can be obtained. That is, when the additional layer 71 is formed, the point that the light beam L15 incident on the through hole H is not observed from above is the same, but the reflectance of the light beam L14 incident on the non-hole portion N can be improved. The effect of making the identification mark brighter can be obtained, and the comparison observation by the reading operator can be made easier.

  As described above, the description has been given on the assumption that each identification mark is observed by observing the reflected light on the upper surface of the illumination light irradiated from above with respect to the medium formed of the net structure. In the case of a medium composed of a body, it is also possible to recognize each identification mark by observing, from above, transmitted light from above the illumination light applied to the lower surface from below. FIG. 38 is a side cross-sectional view showing an example in which the substrate 70 made of a net-like structure is made of a non-translucent material and the illumination light from below is observed from above.

  Since the substrate 70 is made of a non-translucent material, the light beam L17 incident on the non-hole portion N from below is prevented from transmitting upward, but a part of the light beam L16 incident on the through-hole H is upward. (Of course, there is some light that scatters and disappears by colliding with the side surface of the through hole H). Therefore, in the case of the illustrated example, the first identification mark m10 (FIG. 38 (a)) in which the occupied area of the through hole H is larger than the occupied area of the non-hole portion N looks bright, and The second identification mark m20 (FIG. 38 (b)) whose occupied area is larger than the occupied area of the through hole H looks dark. Therefore, with respect to the substrate 70 composed of the net-like structure, it is also possible to confirm the comparison between the two identification marks by observing the transmitted light from the upper surface of the illumination light applied to the lower surface from below from above.

  In the modification shown in FIG. 39, even when a substrate 75 made of a net-like structure is formed using a translucent material, the substrate 75 is formed so that illumination light from below can be observed from above. The additional layer 76 is further provided on the upper surface. Here, as the additional layer 76, a layer made of a light-shielding material is used. In order to create a physical structure as shown in FIG. 39, a patterning device 300 performs a patterning process on a substrate made of a light-transmitting material to form a substrate 75 having a net-like structure. A function of forming the additional layer 76 made of a light-shielding material may be provided on one surface of the hole N.

  In the case of the medium shown in FIG. 39, the light beam L18 transmitted through the through-hole H is directly transmitted upward and observed, but the light beam L19 which is going to transmit through the non-hole portion N is a light-shielding material. Is not obstructed by the additional layer 76 composed of Therefore, in the case of the illustrated example, the first identification mark m10 (FIG. 39 (a)) in which the occupied area of the through hole H is larger than the occupied area of the non-hole portion N looks bright, and The second identification mark m20 (FIG. 39 (b)) whose occupied area is larger than the occupied area of the through hole H looks dark. Even if the substrate 75 is made of a translucent material, the difference in brightness between the two identification marks becomes remarkable by forming the additional layer 76 made of a light-shielding material, and the function as the identification mark according to the present invention is sufficiently achieved. Can be fulfilled.

  As described above, several variations of the structure of the information recording medium have been described. The reflection observation in which the reflected light on the upper surface of the illumination light irradiated from above the medium is observed from above, and conversely, the lower surface is viewed from below. It should be noted that the relationship between the lightness and darkness of each identification mark is reversed in the case where transmission observation in which the transmitted light from the upper surface of the illuminated light irradiated from the top is observed from above is assumed.

  For example, since the medium shown in FIG. 32 is a medium premised on reflection observation, the first identification mark m10 is a mark indicating that “the convex portion is bit“ 1 ””, and the second identification mark m20 is May be set as a mark indicating that the recess is a bit "1". However, since the medium shown in FIG. 35 is a medium premised on transmission observation, the first identification mark m10 has a The second identification mark m20 needs to be a mark indicating that "the convex portion is bit" 1 "". In other words, the medium shown in FIG. 32 and the medium shown in FIG. 35 have the same physical structure, but when the medium shown in FIG. 32 is observed by reflection, the second identification mark m20 (FIG. 32 (b)) looks brighter, but when the medium shown in FIG. 35 is observed through the medium, the first identification mark m10 (FIG. 35 (a)) looks brighter.

  Similarly, since the medium shown in FIG. 37 is a medium premised on reflection observation, the first identification mark m10 is a mark indicating that “the non-hole portion N is bit“ 1 ””, The identification mark m20 may be a mark indicating that “the through hole H is the bit“ 1 ””. However, since the medium shown in FIG. 39 is a medium premised on transmission observation, the first identification mark m10 Must be a mark indicating that the through hole H is the bit "1", and the second identification mark m20 must be a mark indicating that the non-hole N is the bit "1". In other words, the medium shown in FIG. 37 and the medium shown in FIG. 39 have the same physical structure, but when the medium shown in FIG. 37 is observed by reflection, the second identification mark m20 (FIG. 37 (b)) looks brighter, but when the medium shown in FIG. 39 is observed through the medium, the first identification mark m10 (FIG. 39 (a)) looks brighter.

  Actually, when the drawing data E is created by the storage processing computer 100 ′, it is impossible to predict what kind of medium will be finally created by the patterning device 300. Therefore, in practice, as information indicating the method of interpreting the data bits indicated by the respective identification marks m10 and m20, basically, information on the assumption that reflection observation is performed is recorded, and the reading operation is performed. If the user compares the identification marks m10 and m20 by transmission observation, an arrangement may be made to reverse the interpretation method of the data bits.

  It should be noted that specific materials for forming each of the additional layers described above are as described in §2. For example, as the light-reflective material, metals such as aluminum, nickel, titanium, silver, chromium, silicon, molybdenum, and platinum, alloys, oxides, and nitrides of these metals can be used. For example, a material made of a compound such as a metal oxide or nitride can be used. Of course, as described in §2, a similar effect can be obtained by doping impurities on the surface on which the additional layer is to be formed, instead of forming another layer having a clear boundary surface like the additional layer. it can.

<<<< §11. Information storage method according to the present invention >>>>>
Finally, a processing procedure when the present invention is grasped as a method invention called an information storage method will be described with reference to a flowchart of FIG. The information storage process illustrated in FIG. 40 is a process for executing an information storage method of writing and storing digital data on an information recording medium, and includes steps S31 to S36 as illustrated. Here, steps S31 to S34 are processing steps executed by the storage processing computer 100 'shown in FIG. 18, and step S35 is a processing executed by the beam exposure apparatus 200 shown in FIG. The step S36 is a processing step executed by the patterning apparatus 300 shown in FIG.

  First, in step S31, a data input step of inputting digital data D to be stored is executed. The processing content at this stage is the same as the processing content of step S11 in the prior invention shown in FIG.

  Subsequently, in step S32, a main information pattern generation step of generating a main information pattern Pα indicating information of individual data bits constituting the digital data D input in step S31 is executed. The processing contents at this stage are the same as the processing contents of steps S12 to S15 in the prior invention shown in FIG.

  The important point here is that the main information pattern Pα generated in the main information pattern generation stage has a first attribute main area G1 (black area) and a first attribute main area G1 (black area) as illustrated in the partial area p3 in FIG. Predetermined points, each of which is constituted by a two-attribute main area G2 (white area) and corresponding to each data bit, exist in the first attribute main area G1 or exist in the second attribute main area G2. This is a pattern in which binary information of each data bit is represented by the difference between the two.

  On the other hand, in step S33, a sub-information pattern generation step of generating a sub-information pattern Pβ indicating a method of interpreting the data bits indicated by the main information pattern Pα is executed. This stage is a new stage which is not included in the invention of the prior application, and the specific processing content is as described above as the processing function of the sub information pattern generation unit 180.

  An important point here is that, as shown in FIG. 21, the sub-information pattern Pβ is used to present first information composed of characters, numbers, symbols, figures, some of them, or a combination thereof. One or more for presenting a first identification mark m10 having one or more closed areas, and second information composed of letters, numbers, symbols, graphics, a part thereof, or a combination thereof And a second identification mark m20 having a closed area of

  Moreover, as illustrated in the partial area p1 of FIG. 21, a band-shaped first attribute sub-area extending in a direction parallel to the predetermined arrangement axis Z is included in the closed area forming the first identification mark m10. g1 (black area) and band-shaped second attribute sub-area g2 (white area) are alternately arranged in a direction orthogonal to the arrangement axis Z, and are exemplified in the partial area p2 of FIG. As described above, in the closed region forming the second identification mark m20, the band-shaped first attribute sub-region g1 (black region) extending in the direction parallel to the arrangement axis Z and the band-shaped second attribute sub-region g2 (White areas) are alternately arranged in a direction orthogonal to the arrangement axis Z.

  Here, for the closed area constituting the first identification mark m10, the width W1 of the first attribute sub-area g1 is set to be wider than the width W2 of the second attribute sub-area g2, and the second identification mark An important feature of the closed region forming m20 is that the width W2 of the second attribute sub-region g2 is set to be wider than the width W1 of the first attribute sub-region g1.

  Then, in step S34, a drawing data generation step of generating drawing data E for drawing the main information pattern Pα and the sub information pattern Pβ is executed. This processing content is almost the same as the processing content of step S16 in the prior invention shown in FIG. That is, in step S16, the drawing data E is generated based on the main information pattern Pα, but in step S34, the drawing data E is generated based on a combined pattern obtained by combining the sub information pattern Pβ with the main information pattern Pα. Will be performed.

  Here, the drawing data E generated in the drawing data generation stage exposes the first attribute main region G1 and the first attribute sub-region g1 to the second attribute main region G2 and the second attribute sub-region. g2 is drawing data for not exposing, or the second attribute main area G2 and the second attribute sub-area g2 are exposed, and the first attribute main area G1 and This is drawing data for preventing the first attribute sub-region g1 from being exposed, and the width of the first attribute sub-region g1 and the second attribute sub-region g2 constitutes a diffraction grating for visible light. The dimensions are set so that the dimensions can be set.

  Subsequently, in step S35, a beam exposure step of performing beam exposure using an electron beam or a laser beam on a substrate serving as an information recording medium is executed based on the drawing data E generated in step S34. The processing content at this stage is the same as the processing content of step S17 in the prior invention shown in FIG.

  In the last step S36, a patterning step of generating an information recording medium on which a physical structure pattern corresponding to the drawing data E is formed by performing a patterning process on the exposed substrate is executed. The processing content at this stage is the same as the processing content of step S18 in the prior invention shown in FIG. Of course, when employing the structures according to the various variations described in §10, necessary additional layers are formed in step S36.

10: Layer to be molded (before processing)
11: Molded layer (after processing)
12: Network structure 13: Layer to be molded (after processing)
20: resist layer 21: exposed portion 22: non-exposed portion 23: remaining portion 24: remaining portion 31: additional layer (formed on the entire surface)
32: additional layer (formed on the convex portion)
33: additional layer (formed in recess)
40: Supporting layer 51: Molded layer 60: Substrate 61: Additional layer 65 made of a light-reflective material: Substrate 66 made of a light-transmissive material: Additional layer 67 made of a light-shielding material: Additional layer 70 made of a light-shielding material A substrate 71 made of a net-like structure: an additional layer 75 made of a light-reflective material: a substrate 76 made of a light-transmissive material: additional layers 100 and 100 'made of a light-shielding material: a computer 110 for storage processing: a data input unit 120 : Unit data generation unit 130: Unit bit matrix generation unit 140: Unit bit figure pattern generation light rain 150: Unit recording figure pattern generation units 160 and 160 ′: Drawing data generation unit 170: Main information pattern generation unit 180: Sub information Pattern generation unit 200: Beam exposure device 300: Patterning device 310: Development processing unit 320: Etching processing unit 400: Image photographing device 410: Image element 420: Magnifying optical system 430: Scanning mechanism 500: Readout computer 510: Captured image storage unit 520: Bit recording area recognition unit 530: Unit bit matrix recognition unit 540: Scan control unit 550: Data restoration unit Ab, Ab (I): Bit recording areas Au, Au (11) to Au (33): Unit recording area Aα: Main recording area Aβ: Sub recording area Aβ1: First sub recording area Aβ2: Second sub recording area B (U1) , B (Ui): unit bit matrix C: concave portion D: digital data E to be saved E: drawing data F: bit figure G1: first attribute main area G2: second attribute main area g1: first attribute sub area g2 : Second attribute sub-region H: Through hole L: Lattice points L1 to L19: Light beam M: Information recording medium M ': Information recording medium M0: Copy creation medium M1: Original information recording medium M2: Duplicated information Record Recording medium M3: Original information recording medium M4: Duplicated information recording medium M5: Information recording medium (black concave medium)
M6: Information recording medium (black convex medium)
m1 to m25: identification mark m30: auxiliary common identification mark m13a, m13b: each closed area m23a, m23b, m23c of identification mark m13: each closed area m25a, m25b of identification mark m23: each closed area N of identification mark m25: non- Hole P (E): Drawing pattern P (U1), P (Ui): Unit bit figure pattern Pα: Main information pattern Pβ: Sub information pattern p1 to p3: Partial area Q, Q1 to Q43: Alignment mark R (U1) to R (U4), R (Ui): graphic pattern S for unit recording: exposure target substrates S11 to S36: steps U1 to U4, Ui of flow chart: unit data u: predetermined bit length V: convex portion W1 : Width W2 of the first attribute sub-region: width X of the second attribute sub-region X: horizontal coordinate axes X1 to X7: horizontal grid line Y: vertical coordinate axes Y1 to Y7: vertical grid line Z: arrangement axis

Claims (6)

An information recording medium on which digital data is written,
Information of individual data bits constituting digital data to be stored is indicated by arranging a bit figure at a position corresponding to bit "1" and arranging nothing at a position corresponding to bit "0". A main recording area in which a main information pattern is recorded,
A sub-recording area on which a sub-information pattern indicating a method of interpreting the data bits indicated by the main information pattern is recorded;
Have a,
An information recording method, wherein an interpretation method indicating whether to interpret a region inside and outside the bit figure into a bit “1” or a bit “0” is recorded in the sub recording region. Medium. An information recording medium on which digital data is written,
Information of individual data bits constituting digital data to be stored is indicated by arranging a bit figure at a position corresponding to bit "0" and arranging nothing at a position corresponding to bit "1". A main recording area in which a main information pattern is recorded,
A sub-recording area on which a sub-information pattern indicating a method of interpreting the data bits indicated by the main information pattern is recorded;
Has,
Information, characterized in that the interior region and outside the region before Symbol bit graphics, the interpretation that indicates interpreted in any of the respective bit "1" and bit "0" is recorded in the sub recording area recoding media. The information recording medium according to claim 1,
An information recording medium, wherein a main recording area and a sub recording area are formed on the same substrate. The information recording medium according to any one of claims 1 to 3 ,
An information recording medium, characterized in that a main information pattern and a sub information pattern are recorded in an uneven structure. The information recording medium according to any one of claims 1 to 3 ,
An information recording medium, wherein a main information pattern and a sub information pattern are recorded in a network structure having a through-hole and a non-hole. The information recording medium according to any one of claims 1 to 5 ,
In the sub recording area, a first identification mark and a second identification mark that can be visually observed are recorded, and light and darkness are present between the first identification mark and the second identification mark at the time of visual observation. When the first identification mark and the second identification mark are compared and observed, a method of interpreting the data bit is determined based on a criterion “which of the pair of identification marks looks brighter”. An information recording medium characterized by being shown.