JP2001256679A - Method for forming sample for observing information recording layer of optical recording medium and sample for the observing information recording layer of optical recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To observe pits and a rugged recording mark which are recorded in an optical recording medium. SOLUTION: A glass substrate 41, insoluble in an organic solvent (dichloromethane) 43, is bonded to the information recording layer side of a resin substrate 11, (21), (31) with an information recording layer formed on one face, by using an adhesive (epoxy resin) 42 insoluble in the organic solvent 43, and the resin substrate is made to dissolve in the organic solvent to expose the information recording layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical recording apparatus for producing a sample for observing uneven pits or recording marks recorded on an information recording layer of an optical recording medium such as an optical disk, a magneto-optical disk, an optical card and the like. The present invention relates to a method for preparing a sample for observing an information recording layer of a medium and a sample for observing an information recording layer of an optical recording medium.

[0002]

2. Description of the Related Art In recent years, there has been an optical recording medium formed in a disk shape or a card shape in order to record image information or audio information at a high density.

In particular, a disk-shaped optical recording medium includes C
There are a read-only optical disk represented by D (compact disk), a rewritable PC (phase change) optical disk, and a rewritable MO (magneto-optical) optical disk, and a semiconductor laser used for these optical disks. Due to technological improvements such as shorter wavelengths and higher performance of optical pickups, higher densities are progressing rapidly, and fine irregular pits and recordings recorded on optical recording media due to such high densities are increasing. The mark is also smaller. In order to develop an optical recording medium capable of recording smaller pits and recording marks with higher density, it is essential to accurately observe the dimensions and shapes of the recorded pits and recording marks.

[0004]

By the way, the smaller the uneven pits and recording marks recorded on the optical recording medium, the more difficult it is to observe the shape.

Therefore, as an example of a conventional method of observing pits and recording marks recorded on an optical recording medium, there is a method of observing with an optical microscope as shown in FIG.

As shown in FIG. 7, in a read-only optical disk such as a CD, uneven pits (not shown) are formed as recording information on one surface 1a of a resin transparent substrate 1, and a PC (phase change) is formed. In the type) optical disk, a recording layer 2 is formed on one surface 1a of the resin transparent substrate 1 and a recording mark is recorded on the recording layer 2 as recording information. On the recording layer 2, a reflective layer 3 of aluminum or the like and a protective layer 4 are sequentially formed.

[0007] From the other surface 1b side of the resin transparent substrate 1, uneven pits (not shown) of the read-only optical disk or recording marks of the PC (phase change) optical disk are observed with an optical microscope. However, when a read-only optical disc such as a CD or a PC (phase change) optical disc is observed through an optical microscope through a resin transparent substrate 1, the resin transparent substrate 1 having a high refractive index has a thickness of 0.6 to 1.2 mm. The uneven pits (not shown) of the read-only optical disk or the recording marks of the phase-change optical disk were blurred, and the dimensions and shape could not be observed accurately.

Another conventional method for observing uneven pits or recording marks recorded on an optical recording medium is to form the pits on one surface of a resin transparent substrate 1 as shown in FIG. There is also a method in which the protective layer and the reflective layer on the recording layer 2 side are removed and observation is performed.
There is a method of observing the marks on the recording layer 2 by removing the mark with an acid or basic solution. However, in the case of a PC (phase change) type optical disk, the recording marks are not fine irregularities but reflectivity due to crystal-amorphous state. , The change in the reflectance (contrast) due to the crystal-amorphous state is small, and the recording mark is not emphasized because the reflection layer is removed, so that the recording mark can be clearly observed. There was a problem that it was not possible.

As a method of observing a recording mark of a PC (phase change) type optical disk as described above, there is a method of observing with a transmission electron microscope (TEM).
Since the preparation of a thin film sample requires skill and the transmission electron microscope is expensive, it cannot be easily measured.

Further, observation of recording marks recorded on an MO (magneto-optical) type optical disk with a magnetic force microscope has recently started to be performed. In a magneto-optical disk, recording marks as recording information are usually recorded on concentric or spiral lands or grooves, but in order to observe the recording marks recorded with a magnetic force microscope, the magnetic force must be reduced to a certain distance. Since it becomes weak in inverse proportion to the square, it must be measured close to the magnetic recording layer. For this reason, conventionally, a method of peeling the protective layer or the metal reflective layer with an adhesive tape or the like and observing it has been adopted, but in the case of tape peeling, it is not known which layer will be peeled off, and the recording layer to be observed may also be In some cases, they peeled off together.

Therefore, there is a demand for a method that allows simple and more accurate observation of uneven pits or recording marks recorded on an information recording layer of an optical recording medium.

[0012]

Means for Solving the Problems The present invention has been made in view of the above problems, and a first invention is to record information insoluble in the organic solvent on one surface of a resin substrate soluble in the organic solvent. In the method for preparing a sample for observation of an information recording layer of an optical recording medium, a layer is formed, and a sample for observing uneven pits or recording marks optically or magneto-optically recorded on the information recording layer is prepared. After bonding the insoluble substrate to the organic solvent using an adhesive insoluble to the organic solvent on the information recording layer side formed on one surface of the resin substrate, the resin substrate is dissolved with the organic solvent. And exposing the information recording layer side to an information recording layer observation sample of an optical recording medium.

Further, in the method for preparing a sample for observing an information recording layer of an optical recording medium according to the first aspect of the present invention, the resin substrate is made of a polycarbonate resin or an acrylic resin or an alicyclic polyolefin resin, and the organic solvent is an alkyl chloride. Alternatively, an ether type or an aromatic type is used.

According to a second aspect of the present invention, an information recording layer insoluble in the organic solvent is formed on one surface of a resin substrate soluble in an organic solvent, and optical recording or magneto-optical recording is performed on the information recording layer. In the information recording layer observation sample of the optical recording medium created for observing the formed uneven pits or recording marks, on the side of the information recording layer formed on one surface of the resin substrate, the organic solvent The information recording layer of the optical recording medium, wherein after bonding the substrate insoluble in the organic solvent using an insoluble adhesive, dissolving the resin substrate with the organic solvent and exposing the information recording layer side. This is an observation sample.

Further, in the sample for observing an information recording layer of the optical recording medium according to the second invention, the resin substrate is made of a polycarbonate resin, an acrylic resin or an alicyclic polyolefin resin, and an alkyl chloride or ether is used as an organic solvent. Or an aromatic system.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for preparing a sample for observing an information recording layer of an optical recording medium and a sample for observing an information recording layer of an optical recording medium according to the present invention will be described below with reference to FIGS. This will be described in detail.

FIG. 1 is a diagram for explaining a method for preparing a sample for observing an information recording layer of an optical recording medium according to the present invention and the structure of various optical disks applied to a sample for observing an information recording layer of an optical recording medium. , (A) shows a read-only optical disk, (b) shows a PC (phase change) optical disk,
FIG. 2C shows an MO (magneto-optical) type optical disk, and FIG.
3 (a) to 3 (c) are front process diagrams for explaining a method for preparing a sample for observing an information recording layer of an optical recording medium according to the present invention, and FIG.
FIGS. 4A and 4B are diagrams for explaining a method for preparing a sample for observing an information recording layer of an optical recording medium and a sample for observing an information recording layer of an optical recording medium according to the present invention, and FIG. FIG. 5A and FIG. 5B are diagrams showing a state of observing an information recording layer using a sample for observing an information recording layer of a recording medium, FIGS. 5A and 5B are optical micrographs of Example 1 and Comparative Example 1, and FIG. FIG. 6 is a magnetic force micrograph of Example 2.

Before describing the method for preparing a sample for observing the information recording layer of the optical recording medium and the sample for observing the information recording layer of the optical recording medium according to the present invention, FIG. This will be described with reference to a) to (c).

First, as shown in FIG. 1A, a read-only optical disk 10 is provided on one surface 1 of a transparent resin substrate 11.
In FIG. 1a, fine uneven pits are spirally engraved as recorded information, and a metal reflective layer 12 of aluminum or the like is formed on the uneven pits. The protective layer 13 made of a conductive resin is formed.

In the read-only optical disk 10,
By irradiating a laser beam from the other surface 11b of the transparent resin substrate 11, the return light reflected by the metal reflection layer 12 in a state where the pits are transferred in an uneven shape is reproduced. It was formed as an information recording layer.

Next, as shown in FIG. 1B, the PC (phase change) type optical disk 20 has a land portion and a groove portion which are alternately spirally engraved on one surface 21a of a transparent resin substrate 21. On these lands and grooves, a first dielectric layer 22a made of ZnS-SiO2, a recording layer 22b made of a quaternary alloy of Ag, In, Te, and Sb, and a ZnS A second dielectric layer 22c made of SiO 2 is sequentially formed, a metal reflection layer 23 made of a binary alloy of Al and Cr is formed on the information recording layer 22, and further a metal reflection layer 23 is formed on the metal reflection layer 23. The protective layer 24 made of a thermosetting resin is formed.

The PC (phase change) type optical disk 20
Then, by irradiating the laser beam modulated based on the recording information from the other surface 21b of the transparent resin substrate 21 to the information recording layer 22 on the land portion or the groove portion, the information recording layer 2 is formed.
The recording information is recorded in the form of a recording mark or the recorded recording mark is erased by reversibly changing a crystalline state and an amorphous state by a laser beam. At this time, the change from the amorphous state to the crystalline state, that is, erasing, is performed by heating the information recording layer 22 to a temperature higher than the crystallization temperature of the information recording layer 22. Further, since the crystal state has a higher light reflectivity than the amorphous state, the recording marks recorded on the information recording layer 22 can be reproduced.

Next, as shown in FIG. 1 (c), the MO (magneto-optical) type optical disk 30 has a land portion and a groove portion which are alternately spirally formed on one surface 31a of a transparent resin substrate 31. A first dielectric layer 32a made of SiN is formed as an information recording layer 32 on these lands and grooves.
And a recording layer 32b made of a ternary alloy of Tb, Fe and Co
And a second dielectric layer 32c made of SiN are sequentially formed, and a metal reflective layer 3 made of Al is formed on the information recording layer 32.
3 is formed, and a protective layer 34 made of a thermosetting resin is further formed on the metal reflection layer 33.

The MO (magneto-optical) type optical disk 30
Then, a laser beam is irradiated from the other surface 31b of the transparent resin substrate 31, and an external magnetic field is applied to the information recording layer 32 in accordance with the recording information corresponding to the irradiation position of the laser beam to record a recording mark. By irradiating a laser beam that is weaker than at the time of recording at the time of reproduction, and detecting the polarization angle of the reflected light that depends on the recording magnetization direction of the return light reflected by the metal reflection layer 33, the recording mark is formed. Will be played.

The transparent resin substrate 11 used for the read-only optical disk 10 and the transparent resin substrate 21 used for the PC (phase change) optical disk 20
The transparent resin substrate 31 used for the MO (magneto-optical) type optical disk 30 is formed in a disk shape by injection molding a thermoplastic resin in terms of productivity and cost. For example, the most frequently used thermoplastic resins include polycarbonate and polymethyl methacrylate.

The thermoplastic resin includes not only polycarbonate and polymethyl methacrylate but also polystyrene, poly (α-methylstyrene), polyindene, poly (4-methyl-1-pentene), polyvinylpyridine, polyvinylformal, and polyvinyl acetal. , Polyvinyl butyral, polyvinyl acetate, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride, polyvinyl methyl ether, polyvinyl ethyl ether, polyvinyl benzyl ether, polyvinyl methyl ketone, poly (N-vinyl carbazole), poly (N-vinyl pyrrolidone) , Polymethyl acrylate, polyethyl acrylate, polyacrylic acid, polyacrylonitrile, polymethyl methacrylate, polyethyl methacrylate, polybutyl methacrylate, poly Methacrylic acid benzyl, poly cyclohexyl methacrylate, polymethacrylic acid, polymethacrylic acid amides, polymethacrylonitrile polyacrylonitrile, poly acetaldehyde, poly chloral, polyethylene oxide, polypropylene oxide, polyethylene terephthalate,
Polybutylene terephthalate, polycarbonates (bisphenols + carbonic acid), poly (diethylene glycol bisaryl carbonate) s, 6-nylon, 6,6
-Nylon, 12-nylon, 6,12-nylon, polyethyl aspartate, ethyl polyglutamate, polylysine, polyproline, poly (γ-benzyl-L-glutamate), methylcellulose, ethylcellulose,
Benzyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, acetyl cellulose, cellulose triacetate, cellulose tributyrate,
Resins such as polyurethane resins, organic polysilanes such as poly (phenylmethylsilane), organic polygermanes, and copolymers or copolycondensates thereof can also be mentioned.

The transparent resin substrate 11 used for the read-only optical disk 10, the transparent resin substrate 21 used for the PC (phase change) optical disk 20, and the transparent resin substrate 21 used for the MO (magneto-optical) optical disk 30. Resin substrate 3
No. 1 uses a thermoplastic resin as described above, and since this type of thermoplastic resin is a linear polymer and is not crosslinked, it is soluble in an organic solvent. As this kind of organic solvent, for example, an alkyl chloride solvent such as dichloromethane, chloroform or carbon tetrachloride, an ether solvent such as diethyl ether or tetrahydrofuran, or an aromatic solvent such as benzene, toluene or xylene is used. For example, the resin substrates 11, 21, 31 can be easily dissolved.

Here, the method for preparing the sample for observing the information recording layer of the optical recording medium and the sample for observing the information recording layer of the optical recording medium according to the present invention are described in the following.
It was noted that 1,31 was easily dissolved.

On the other hand, the metal reflection layer 12 and the protective layer 13 formed on one surface 11a of the resin substrate 11 of the read-only optical disk 10 and the one surface 21a of the resin substrate 21 of the PC (phase change) optical disk 20 Information recording layer 22, metal reflective layer 23, protective layer 24, and MO (magneto-optical)
It was confirmed that the information recording layer 32, the metal reflective layer 33, and the protective layer 34 formed on one surface 31a of the resin substrate 31 of the type optical disk 30 were all insoluble in the above-mentioned organic solvents.

Therefore, as shown in FIGS. 2A to 2C, a glass substrate is prepared as the substrate 41 insoluble in the organic solvent, and the thermosetting adhesive 4 insoluble in the organic solvent is prepared.
An epoxy resin is prepared as 2. At this time, thermosetting adhesives insoluble in organic solvents include, for example, ultraviolet curable resins such as epoxy acrylate and urethane acrylate, and thermosetting resins such as epoxy resins and phenolic resins. Since it is a polymer, it is generally confirmed that it is insoluble in an organic solvent. In this example, an epoxy resin is used, but the present invention is not limited to this.

Then, as shown in FIG. 2A, first, an epoxy resin 42 is dropped on a glass substrate 41 insoluble in the organic solvent as a thermosetting adhesive insoluble in the organic solvent.

Next, as shown in FIG. 2B, the above-mentioned resin substrate 11 or resin substrate 21 or resin substrate 31
With the information recording layer formed on one side of the glass substrate 41 facing down, this information recording layer is
Adhere on top.

Next, as shown in FIG. 2 (c), the resin substrates 11, (21) and (31) are heated for about 12 hours in a state where the resin substrates 11, (21) and (31) are brought into close contact with the glass substrate 41 via the epoxy resin 42. Then, the epoxy resin 42 is cured. This FIG. 2 (a)
Steps (c) to (c) are previous steps before using an organic solvent.

Next, as shown in FIG. 3A, the resin substrate 11, (21), (31) completely adhered to the glass substrate 41 via the epoxy resin 42 is treated with an organic solvent. 43 (for example, an alkyl chloride solvent such as dichloromethane, chloroform and carbon tetrachloride, an ether solvent such as diethyl ether and tetrahydrofuran, or an aromatic solvent such as benzene, toluene and xylene). Soak completely. Then, the organic solvent 43 is immersed in the container 44 filled with the organic solvent 43 for several minutes to several days while being stirred by the stirrer 45, so that the thermoplastic resin substrates 11, (21), and (31) become organic solvent 43. Is dissolved and removed. At this time, the information recording layer side formed on the resin substrates 11, (21) and (31) is insoluble in the organic solvent 43, so that the epoxy resin 42
As a result, it is in a state of being adhered to the glass substrate 41.

Further, the resin substrates 11, (21), (31)
In a state where has been removed, rinse with a new organic solvent,
Thereafter, the remaining organic solvent is removed at room temperature or in an oven, so that the thermoplastic resin substrates 11, (2
1) and (31) can be completely removed.

Then, as shown in FIG. 3 (b), when the resin substrates 11, (21) and (31) are removed, the information recording layer is bonded to the glass substrate 4 with an epoxy resin 42.
1 is obtained as a sample for observing an information recording layer of an optical recording medium.

Next, when the information recording layer is observed with an optical microscope or a magnetic force microscope using the information recording layer observation sample of the optical recording medium obtained as described above, the read-only optical disk 10 In this case, although the illustration is omitted here, the metal reflective layer 12 to which the pits having irregularities are transferred is the outermost surface, and the protective layer 13 below the metal reflective layer 12 is Since the metal reflection layer 41 is adhered to the metal reflection layer 12, the size and shape of the uneven pits can be accurately determined by observing the metal reflection layer 12 with an optical microscope.

In the case of the PC (phase change) type optical disk 20, as shown in FIG. 4, the information recording layer 22 is the outermost surface, and the metal reflection layer 23 and the protection layer 24 below the information recording layer 22. Is bonded to the glass substrate 41 via the epoxy resin 42, so that the information recording layer 22 is
Is observed, the recording mark recorded on the information recording layer 22 is emphasized by the metal reflection layer 23, so that the dimensional shape of the recording mark can be accurately understood.

Also, in the case of the MO (magneto-magnetic) type optical disk 30, although the state is almost the same as that of FIG. 4, the recording marks recorded on the information recording layer 32 are observed here by a magnetic force microscope. .

<Example 1> A PC (phase change) was prepared using the method for preparing a sample for observing an information recording layer of an optical recording medium according to the present invention.
The recording marks recorded on the information recording layer of the optical disk were observed.

First, film formation of a PC (phase change) type optical disk was performed in the following procedure.

The resin substrate used here has a diameter of 120 m.
m, made of polycarbonate resin having a plate thickness of 0.6 mm and a track pitch of 0.74 μm (groove pitch 1.48 μm)
m), the groove depth was 35 nm, and the ratio between the groove width and the land width was about 40:60 (%).

Further, while the resin substrate is rotated in a planetary manner at 60 rotations per minute, the first recording layer serving as an information recording layer is formed by sputtering.
Vacuum film formation was performed in the order of the protective layer, the recording layer, the second dielectric layer, and the metal reflective layer on the information recording layer. First, after evacuating the inside of the vacuum chamber to 6 × 10 −5 Pa, 1.6 × 10
Ar gas of -1 Pa was introduced. And ZnS-Si
O2 was used to form a first dielectric layer having a thickness of 50 nm on a resin substrate by a high-frequency magnetron sputtering method. Then, A
A recording element was formed by sputtering a four-element single target (diameter: 2 inches, thickness: 3 mm) consisting of g, In, Te, and Sb with a DC power supply, and the thickness of the recording layer was 20 nm. Further, a second dielectric layer made of the same material as the first dielectric layer is formed to a thickness of 15 nm, and a two-element single target made of Al and Cr is formed thereon by DC sputtering to obtain a composition Al: 97
%, Cr: 3%, and a metal reflective layer having a thickness of 250 nm was formed.

Thereafter, the resin substrate on which the information recording layer and the metal reflection layer were formed was taken out of the vacuum vessel, and an acrylic ultraviolet curable resin (XR1 manufactured by Sumitomo Chemical Co., Ltd.) was placed on the metal reflection layer.
1) was spin-coated and cured by irradiation with ultraviolet rays to form a protective layer having a thickness of 10 μm, thereby obtaining a PC (phase change) optical disk.

The PC (phase change) type optical disk thus manufactured is irradiated with a laser beam, a flash lamp, or the like, and the information recording layer is heated to a temperature higher than the crystallization temperature to perform an initialization process. Practically, a converged laser beam is used using an initialization device and an evaluator as described in JP-A-7-282475. First, a PC (phase change) type optical disk is mounted on the spindle of the initialization device, and then the laser beam is irradiated with a high output laser beam to heat the information recording layer to change to a high reflectance state. The laser beam applied to the PC (phase change) optical disk has a beam diameter larger than the track width, and is preferably longer in the radial direction, and simultaneously initializes a plurality of tracks while rotating the PC (phase change) optical disk. I do. Specifically, the wavelength of the initialization laser is 830 nm, and the shape of the irradiation beam is 2 μm in the track direction and 20 μm in the radial direction.
It has a wide shape. A PC (phase change) optical disk was rotated at a linear velocity of 3 m / s, and initialization was started from a radius of 22.0 mm. The initialization laser was moved at a speed of 30 μm / rotation in the radial direction at a power of 400 mW, and the initialization was completed at a radius of 58.0 mm.

Subsequently, an information signal was recorded on the PC (phase change) type optical disk. Recording was performed as follows using a recording machine having a laser light of 635 nm wavelength as a light source. At a linear velocity of 3.5 m / s, the modulation signal is an 8-16 modulation random pattern, and the clock cycle T is 38.2 nanoseconds (n
s). Then, recording was performed from the other surface side of the resin substrate to a groove portion which is a guide groove of the information recording layer. The recording conditions were a peak power of 12 mW and an erasing power of 6.0 m.
W, cooling power 1.0 mW. The length of the minimum recording mark among the recording marks recorded on the information recording layer under this condition is about 0.4 μm.

Subsequently, this PC (phase change) type optical disk was adhered to the glass substrate from the information recording layer side using an acrylic ultraviolet curing resin (XR11 manufactured by Sumitomo Chemical). Before the resin was applied to the glass substrate with a syringe and cured, the above-mentioned recorded PC (phase change) optical disk was brought into close contact with the glass substrate and irradiated with ultraviolet rays from the glass substrate side. Output 210m
A J / cm2 mercury lamp was irradiated for 1 minute.

After the acrylic UV-curable resin was cured, the PC (phase change) optical disk adhered to the glass substrate was set in a chloroform solvent so as not to fall. The resin substrate was dissolved with a chloroform solvent by leaving it as it was for 20 minutes. Thereafter, the glass substrate to which the information recording layer was adhered was taken out, and the surface was washed with fresh chloroform. Thereafter, the glass substrate having the information recording layer side adhered to a clean oven maintained at 60 ° C. for about 30 minutes to completely remove the organic solvent.

From the information recording layer side, the state of the recording mark of the sample (sample) from which the resin substrate (polycarbonate substrate) was removed was observed using an optical microscope. Observation results show that, as shown in FIG. 5A, the recording marks recorded on the information recording layer are emphasized by the metal reflection layer, so that the recording marks are clearly seen, and the dimensions and shape of the recording marks can be accurately confirmed. Condition.

<Comparative Example 1> A PC (phase change) type optical disk in which a film was formed under the same conditions as in Example 1 and signal recording was also performed under the same conditions was performed in the same manner as described earlier with reference to FIG. To
A recording mark recorded on the information recording layer was observed from the other surface of the resin substrate through the resin substrate. 680n wavelength for observation
The measurement was performed using a laser microscope having a laser beam of m as a light source. The result is, as shown in FIG.
As shown in (a), the image of the edge portion of the recording mark was considerably unclear as compared with the observation using the method of the present invention.

Example 2 Using the method for preparing a sample for observing an information recording layer of an optical recording medium according to the present invention, recording marks recorded on the information recording layer of a commercially available MO (magneto-optical) optical disk were observed. .

First, a medium having a capacity of 230 MB and 3.5 inches
Information was written to an O (magneto-optical) type optical disk using an MO drive connected to a personal computer. The resin substrate was removed from this MO (magneto-optical) optical disk in the same manner as in Example 1. Since the thickness of the resin substrate of this MO (magneto-optical) type optical disk was 1.2 mm, the time for leaving it in chloroform was set to 35 minutes. This MO (magneto-optical) type optical disk was observed using a magnetic force microscope. The observed photograph is shown in FIG. Even in this case, the recording marks recorded on the information recording layer were clearly seen, and the dimensions and shape of the recording marks could be confirmed accurately.

[0053]

According to the method for preparing a sample for observing an information recording layer of an optical recording medium and the sample for observing an information recording layer of an optical recording medium according to the present invention described in detail above, a film is formed on one surface of a resin substrate. After bonding the substrate insoluble in organic solvent to the information recording layer side using an adhesive insoluble in organic solvent, the resin substrate is dissolved in organic solvent to expose the information recording layer side. The uneven pits or recording marks recorded in the layer can be observed from the information recording layer side, and can be observed in a state where the metal reflective layer is formed under the information recording layer. Since the pits or the recording marks are emphasized by the metal reflection layer, the uneven pits or the recording marks are clearly seen, and there is an effect that the size and shape of the uneven pits or the recording marks can be accurately confirmed.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining a method for preparing a sample for observing an information recording layer of an optical recording medium and a structure of various optical disks applied to a sample for observing an information recording layer of the optical recording medium according to the present invention.

FIG. 2 is a pre-process diagram for explaining a method for preparing a sample for observing an information recording layer of an optical recording medium according to the present invention.

FIG. 3 is a diagram for explaining a method for preparing a sample for observing an information recording layer of an optical recording medium and a sample for observing an information recording layer of an optical recording medium according to the present invention.

FIG. 4 is a diagram showing a state in which the information recording layer is observed using the information recording layer observation sample of the optical recording medium according to the present invention.

5 is an optical microscope photograph of Example 1 and Comparative Example 1. FIG.

FIG. 6 is a magnetic force micrograph of Example 2.

FIG. 7 is a diagram showing an example of a conventional method for observing pits and recording marks recorded on an optical recording medium.

FIG. 8 is a diagram showing another conventional method for observing pits and recording marks recorded on an optical recording medium.

[Explanation of symbols]

10: read-only optical disk, 11: resin substrate, 11a
... one surface, 12 ... metal reflection layer, 13 ... protection layer, 20 ...
PC (phase change) type optical disk, 21 ... resin substrate, 21a
... one surface, 22 ... information recording layer, 23 ... metal reflection layer, 2
4 Protective layer, 30 MO (magneto-optical) type optical disk, 31
... resin substrate, 31a ... one surface, 32 ... information recording layer, 3
3: Metal reflective layer, 34: protective layer, 41: glass substrate, 4
2: thermosetting adhesive (epoxy resin); 43, organic solvent; 44, container.

Claims (4)

[Claims] An information recording layer insoluble in an organic solvent is formed on one surface of a resin substrate soluble in an organic solvent, and the information recording layer is optically or magneto-optically recorded in an uneven pit. Or in the method for preparing an information recording layer observation sample of an optical recording medium for preparing a sample for observing a recording mark, the information recording layer formed on one surface of the resin substrate, insoluble in the organic solvent After adhering a substrate insoluble in the organic solvent using an adhesive, dissolving the resin substrate with the organic solvent to expose the information recording layer side, for observing the information recording layer of the optical recording medium. Sample preparation method. 2. The method according to claim 1, wherein said resin substrate is made of a polycarbonate resin, an acrylic resin, or an alicyclic polyolefin resin, and said organic solvent is an alkyl chloride, ether, or aromatic resin. A method for preparing a sample for observing an information recording layer of an optical recording medium. 3. An information recording layer insoluble in said organic solvent is formed on one surface of a resin substrate soluble in an organic solvent, and uneven pits optically or magneto-optically recorded in said information recording layer. Or in the information recording layer observation sample of the optical recording medium created for observing the recording mark, on the information recording layer side formed on one surface of the resin substrate, using an adhesive insoluble in the organic solvent A substrate for observing an information recording layer of an optical recording medium, wherein a substrate insoluble in the organic solvent is adhered to the resin substrate and the resin substrate is dissolved with an organic solvent to expose the information recording layer side. 4. The method according to claim 3, wherein said resin substrate is made of a polycarbonate resin, an acrylic resin or an alicyclic polyolefin resin, and said organic solvent is an alkyl chloride, an ether or an aromatic. A sample for observing the information recording layer of an optical recording medium.