JPS6027592B2 - Heat mode recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat mode recording medium and a recording method.

2. Description of the Related Art Conventionally, various methods have been known for optically performing high-density recording when recording high-frequency signals, such as video signals, on a recording medium.

For example, a recording layer is provided on a support, the recording layer is irradiated with an energy beam (laser beam, electron beam, etc.), and the heat generated thereby forms recesses (this is called heat mode recording), and this is recorded as is. There is a way to use it as a board.

This method has a high recording speed and does not require development processing, but the periphery of the recess (recorded bit) formed by the beam may bulge irregularly or be removed by evaporation or melting to form the recess. This was accompanied by a phenomenon in which a portion of the recorded layer was scattered and attached to the surface of the recording layer.
Therefore, regardless of the type of reproduction method, the signal to noise ratio of the obtained signal itself is not good.
When a piezoelectric type or the like is used, an extremely large mechanical force acts on the reproducing element, which has the drawback of significantly shortening the life of the reproducing element. The present invention aims to solve all of the above-mentioned drawbacks, and provides a new and excellent heat mode recording medium and recording method, which can also be called heat mode etching recording.

The present invention that achieves the above object is a heat mode information recording method in which an energy beam is selectively irradiated onto a recording medium having a heat mode layer and an information recording layer to be etched, and heat generated by the energy beam is generated. This recording method is characterized by comprising the steps of selectively removing the heat mode layer, etching away the exposed portion of the information recording layer using the heat mode layer as an etching mask, and removing the remaining heat mode layer. Further, as a recording medium suitable for the method, there is provided a recording medium having a heat mode layer which can be selectively removed by heat generated by an energy beam and whose entire layer can be removed, and an information recording layer which can be selectively removed by dissolution. Furthermore, the present invention provides a recording method for producing a large number of duplicate discs using the recording disc obtained by the above method as a master. The recording medium and recording method of the present invention will be explained in detail below.

In the present invention, the basic structure of the recording medium consists of a heat mode layer, an information recording layer, and a substrate. However, the heat mode layer is a layer that is removed by thermal action such as evaporation or melting by a beam, and the information recording layer is a layer that is selectively etched using the heat mode layer as a mask.
Represents the layer where final information recording is performed. Examples of the substrate include glass, ceramics, organic polymers, and metal plates, and the shape of the substrate is selected from sheet, film, or hard plate depending on the purpose.

Further, as the heat mode layer and the information recording layer to be selectively etched, any combination of chalcogen or chalcogenide, metal, organic polymer, glass, etc. can be used. The chalcogen or chalcogenide used in the present invention is a substance containing at least one of the iodine group elements (S, Se, Te) as a main component, not only in stoichiometric proportions but also in any proportion.

Typical examples that are effective in the present invention include simple substances such as S, Se, and Te, Ce-S system, G-Se system, Ct-Te system, As-S system, As-Se system, As-Te system, S-Se
system, Se-Te system, Te-S system, Sb-S system, Sb-S
e series, Sb-Te series, Bi-S series, Bi-Se series, Bi
-Te-based binary chalcogens, or As-S-Te-based, As-Se-Te-based, Sb-As-S-based ternary chalcogens. To name a few specific things, W.
S, C is also 2S3, Cmo S2, As2 is also Sbbu3, Bi
These are intersection 3, Bjbue3, Bi2Te3, etc. Furthermore, various mixed systems of the chalcogen or chalcogenide substances,
Or Tso (thallium), halogen, Cu. Ag, Cd
, Pb, etc., or alkali metals such as Na, K, Ca, Sr
Chalcogen containing alkali metals such as Si, Q, Wb group elements of the periodic table, lanthanum rare metals such as E-san Sm, actinide rare metals such as U, etc., singly or in various combinations. Alternatively, chalcogenide may also be used.

Note that many of these substances are soluble in alkaline solutions, but exhibit strong resistance to acids. Metals used in the present invention include Cr, Nj, Fe, C〇, Cu, Ag, A
u, Zn, A〆, Cd, M〇, Rh, Pd, Pt, lr
, Bi, Sn, Pb, and ln, and alloys containing these metals. Further, semiconductors such as Q and Si are also used. Examples of organic polymer substances include polymethyl methacrylate, polyisobutyl methacrylate, polyethylene, polypropylene, polystyrene, polyvinyl chloride, styrene acrylonitrile copolymer, vinyl chloride-vinylidene chloride polymer, polyvinyl butyral, cellulose acetate, Common organic polymers such as POIJ carbonate are used.

Further, the etching solution used in the present invention is appropriately selected depending on the properties of the materials used for the heat mode layer and the information recording layer. To give some specific examples, typical acids or oxidizing solutions include nitric acid, sulfuric acid (including dilute sulfuric acid, hot concentrated sulfuric acid, etc.), and chromic acid mixture (
K2Cr207-S04), aqua regia, ammonium nitrate solution, ferric nitrate solution, etc.
, aqueous or alcoholic solutions of hydroxides of alkali metals such as , Nb and K, or alkali metals such as Ba and Ca, and ordinary organic solvents. The most common etching method is to use the liquid as described above, but various wet treatments such as spraying the liquid may also be used.

The configuration or recording method of the present invention will be described below with reference to the drawings.

FIG. 1 shows the basic configuration of the present invention.

That is, on a suitable substrate 1, an information recording layer 2 is etched.
Depending on the material to be laminated, it is formed by a known method such as vapor deposition, sputtering, or especially in the case of an organic polymer layer, coating, ultraviolet rays, electron beam polymerization, etc., and then a heat mode layer is formed on it. 3 is formed in a similar manner. Figures 2a, b and c show examples in which a chalcogen or chalcogenide layer selected from the above-mentioned series of materials is used as the heat mode layer and a metal layer is used as the information recording layer.

However, in these figures, numbers 1, 2, and 3 refer to the first
Similarly to the figure, a substrate, an information recording layer, and a heat mode layer are shown, respectively. As shown in FIG. 2a, an energy beam 6 corresponding to information is irradiated, and the heat forms a recess (recording bit) in a part of the upper chalcogen or chalcogenide layer 3.

At this time, scatterings 4 of chalcogen or chalcogenide or raised portions 5 around the removed portions are generated on the heat mode layer, and a good recording disc cannot be obtained as it is. Next, as shown in FIG. 2b, the metal layer in the beam irradiated area is selectively etched using an etching solution that does not dissolve the chalcogen layer 3 but only the metal layer 2 (for example, a normal acid or an oxidizing solution is used). do. The chalcogen or chalcogenide layer 3 remaining at this time acts as an etching mask and forms the recesses 7 (recording bits) in the metal layer.
form. Then, as shown in FIG. 2c, by dissolving and removing all the remaining chalcogen layer 3, scattered particles 4, raised portions 5, etc. with an alkaline etching solution, it is possible to record a good surface condition that cannot be obtained with the conventional method. .
The side walls of the recesses 7 are etched very ideally, giving a recording medium excellent in terms of resolution. In general, the thickness of the heat mode layer or information recording layer must be determined uniquely because it depends on the magnitude of the beam energy, the diameter of the beam, the reflected flow of the material forming the layer, thermal conductivity, specific heat, etc. Although it is difficult to do so, the heat mode layer is easily removed by the energy beam, no thermal changes such as melting or evaporation occur in areas other than those corresponding to the energy beam, or the information recording layer and substrate are not exposed to the energy beam. Taking into account that there is no significant change due to the change in temperature, the range is approximately 0.03 to 0.5 degrees, particularly preferably 0.00 degrees.
It is preferable to set it in the range of 0.05 to 0.3.

On the other hand, the thickness of the information recording layer is determined so that not all of the layer is removed by the beam or to improve etching performance.
0.1 due to conditions such as ensuring a large S/N ratio during regeneration.
The thickness is in the range of ~1 μm, particularly preferably in the range of 0.2 to 0.4 μm, but as compared to the heat mode layer, strict conditions are not imposed on the thickness. For example, if the layer is thick, etching may be performed halfway through the layer. In addition, after the information recording by etching is completed, as a method to remove all of the remaining heat mode layer, the above example describes a method of dissolving and removing it with an etching solution, but as another method, it is possible to remove the remaining heat mode layer by dissolving it with an etching solution. A method such as evaporation or melting removal may be used to prevent this from occurring.

Furthermore, as a variation of this, a chalcogen or chalcogenide layer may be formed as a heat mode layer on a sufficiently polished metal slope that serves both as an information recording layer and a substrate.

In this case, after heat mode recording, if the metal plate is etched to a certain depth, recording will be performed in the same manner as described above. Next, an example of a recording medium in which the heat mode layer is a metal layer and the information recording layer is an organic polymer layer will be described.

An acid-resistant organic polymer selected from the above-mentioned polymers is formed in the form of a thin film on a substrate, and a metal layer is further formed thereon in the same manner as in the above example. First, a part of the metal layer is evaporated or melted away using an energy beam, and then the organic polymer layer is selectively etched using an organic solvent using the remaining metal layer as a mask. Then, by dissolving and removing all remaining metal layers, scattered objects, and raised portions using acid or an oxidizing solution, an excellent recording disc similar to the above example is obtained. To briefly explain an example in which the heat mode layer is an organic polymer layer and the information recording layer is a metal layer, the heat mode layer is removed with a beam, and then the metal layer is selectively etched with an acid or an oxidizing solution. Next, all remaining organic polymer layers are removed using an organic solvent. However, the organic polymer layer used here is made of acid-resistant material. Note that in this example as well, a metal plate that also serves as a housing for the information recording layer and the substrate may be used. As another example, FIG. 3a shows an example in which a chalcogen or chalcogenide layer 9 is used as the heat mode layer, and an ordinary glass plate 8 is used which also serves as an information recording layer and a substrate.

At this time, due to the irradiation of the beam 6, scattered objects 10 or peripheral raised portions 11 are generated as in FIG. 2a. Next, as shown in FIG. 3B, using the chalcogen or chalcogenide layer 9 as a mask, a portion of the glass plate 8 is selectively etched with hydrofluoric acid to form recesses (recording bits) 12.
Thereafter, by alkali etching the remaining chalcogen or chalcogenide layer 9, scattered objects 10, raised portions 11, etc., recording is performed as shown in FIG. 3c. This example has an extremely simple layer structure, provides good resolution, and is an excellent recording method with simplified processing steps. Note that the recording method in which the heat mode layer is a chalcogen or chalcogenide layer and the information recording layer is an organic polymer layer is the same as the above example, and therefore will not be described here.

The recording method and recording medium of the present invention are excellent as various information recording media, and are widely applied to, for example, micro images, super micro images, COM, micro facsimile, video signal recording, etc.

Among these, application to sheets or disks for recording video signals is very preferable. That is, when the present invention is applied to a recording medium for video signals, real-time, high-resolution recording is possible, and the structure is simple and processing is easy. In addition, since the surface of the recording disk is extremely smooth when information is recorded, and the shape of the recording bits is also good, the S/N ratio of the reproduced signal is improved, and the life of the recording element is naturally shortened because it does not damage the reproduction element. It has the advantage of being long. Furthermore, the recording medium of the present invention is extremely preferable for the above reasons when used as a master for obtaining a large number of carved discs after recording.

Among the various configurations of the present invention, when considering the fact that the heat mode layer is easy to remove and that the information recording layer or the substrate is not significantly changed by the beam, the combination of the heat mode layer and the information recording layer is a chalcogen layer. or a chalcogenide layer-metal layer (or metal plate), an organic polymer layer-metal layer (or metal plate), a chalcogen or chalcogenide layer-glass plate type, and "particularly chalcogen or chalcogenide layer-metal layer (or Types of glass plates (metal plates), chalcogen or chalcogenide layers are preferred.Various embodiments of the above-mentioned examples are preferably used as recording media for the recording method of the invention.

For example, when the information recording layer or the substrate is composed of an organic polymer layer that is susceptible to thermal deformation, a reflective layer (generally Alternatively, an anti-reflection layer may be provided on the heat mode layer to improve energy efficiency. The present invention will be explained more specifically using the examples above.

Example 1 a Cr was vacuum-deposited to a thickness of about 0.3 mm on a glass disk with a thickness of about 1 mm and about 30 mm.

Vapor deposition conditions were tungsten board, vacuum degree 8×10-6
Tom, Yoshiharu source temperature was about 1200℃. Next, W2S3 was vacuum deposited on the Cr layer to a thickness of about 0.3 mm.
The deposition conditions were a tungsten board, a degree of vacuum of 1×10 orr, and an evaporation source temperature of about 700°C.

A recording medium was obtained in the manner described above. The bag counterfeit used for recording had the basic configuration shown in FIG.

That is, an argon ion laser 13 with an output of about IW, an optical modulator 15 driven by a video signal 14, a reflector 16,
an optical system consisting of ten sound microscope objective lenses 17 for condensing light, a turntable 19 that rotates in a plane perpendicular to the optical axis of the light beam 18 emitted from this optical system, and a motor 20 for driving the turntable; Furthermore, it consists of a drive system including a structure that moves the reflecting mirror 16 and the condensing lens 17 integrally in the horizontal direction in response to the rotation of the turntable. For this device, the recording medium 21 is placed on the surface of the recording medium 21 with a condensed beam (
The spot size has a nearly rectangular shape with a length of about 3 mm in the direction perpendicular to the middle peak in the scanning direction.
) mounted to match the focus of the image. The turntable was rotated at 180 rpm, and the heat mode layer (Q2S
3 layers). Next, the Cr layer of the information recording layer was etched with dilute sulfuric acid until the bits reached the glass surface. Furthermore, the upper technique 2S3 was dissolved and removed for 6 seconds with a NaOH/ethanol saturated solution. When the recording medium on which recording was performed as described above was observed using a 500-pitch scanning electron microscope, no scattered particles or bulges were observed on the surface of the recording disk, and the shape of the recording bits was also very good. It was good.

Further, as described below, chalcogen or chalcogenide and metal were changed to perform recording as a heat mode layer and an information recording layer, and an etching process was performed.

The table also shows the liquid used for etching or dissolving and removing each substance, and when forming layers of these substances, the deposition conditions were similar to those in a) above. All of these recording media gave good results similar to example a).

Example 2 A WS layer (thickness approximately 0.2〃) was formed by vacuum deposition under the same conditions as in Example 1 on an A-finish disk with a diameter of 30 mm on a side surface that had been thoroughly polished and recorded. It was used as a medium.

Next, recording was performed on the heat mode layer using the recording device used in Example 1, and the A base plate was selectively etched (to a depth of about 0.2 r) using hydrochloric acid, and then the A base plate was selectively etched using a dilute Na2C03 solution.
was dissolved and removed for a short time to obtain a record disc. Although the surface of the recording disk had changed slightly, the condition of the surface and recording bits was quite good, and the resolution was sufficient for practical use.
Example 3 Polymethyl methacrylate is formed into a uniform layer of about 1 layer on a glass substrate with a thickness of about 1 mm and a diameter of 30 mm using a bar code or dip coating method, and Te is coated on top of it with a thickness of about 0.3 mm.
A recording medium was prepared by vacuum evaporation.

The same apparatus as in Example 1 was used, and the laser beam output was set at about 500 hW to perform heat mode with a diameter of about 1 mm.

Furthermore, polymethyl methacrylate was selectively etched (about 0.3 mounds in depth) using the remaining Te layer as a mask using methyl ethyl ketone, and then the Te layer was dissolved and removed using a concentrated NaOH solution. The surface of the finally obtained recording disk was extremely smooth, and the recording bits were in good condition and had a sufficient resolution of 1000 lines/rib or more. Furthermore, a similar structure was obtained by using polyethylene instead of polymethyl methacrylate in the above example.

That is, in the same bell jar, a polyethylene layer was vacuum-deposited to a thickness of about 0.3 μm (conditions: boat temperature about 28 μm).
0 to 290° C. and a vacuum degree of 1×10-4 tom), followed by Te5 with Se instead of Te.
The layer was vacuum-deposited to a thickness of about 0.07 mm to form a recording medium.
With the same recording device as in Example 1, with a heat mode recording device,
Heat mode recording was performed. The treatment was carried out in the same manner as above except that a benzene hot bath was used as the etching solution for polyethylene. The condition of the record disc obtained was the same as that of the above example. Example 4 A layer of polymethyl methacrylate was coated on a glass plate in the same manner as in Example 3, and Bi was further applied on top of it by vacuum deposition (conditions: boat temperature 790°C, vacuum degree 3-4×
10-Pre-orr) A recording medium was formed with a thickness of about 0.1 mm.

Heat mode recording was performed on the Bi layer using the same method and conditions as in Example 3, and after etching the polymethyl methacrylate with methyl ethyl ketone, all the remaining Bi layer was dissolved and removed with dilute HN03 to prepare a recording disk. The surface of the record and the recording tracks were in good condition. Example 5 A Cr layer with a thickness of approximately 0 was formed on a substrate similar to that of Example 1.
．． Vacuum deposition was performed on three peaks.

Further, polyethylene was vacuum-deposited thereon to a thickness of about 0.1 μm. These vapor deposition conditions were almost the same as in Examples 1 and 3. Heat mode recording was performed on this recording medium using the apparatus used in Example 1.

Note that the output of the laser beam was approximately 500W. Next, the Cr layer was etched for a short time using concentrated hydrochloric acid using the remaining polyethylene layer as a mask, and then the remaining polyethylene layer was dissolved and removed in a benzene warm bath.

As with Examples 1, 2, and 3, the surface and track conditions of the recording disc thus obtained were extremely ideal. Example 6 A recording medium was prepared in which a polyethylene layer was formed to a thickness of about 0.3'' by vacuum evaporation under the same conditions as in Example 3 on the A disk used in Example 2.

Heat mode recording with a diameter of about 1 mm was performed using the same recording apparatus as in Example 1 with a laser beam output of about 2 W.
Next, etching was performed using a dilute NaOH solution (to a depth of approximately 0.3 mm), and finally, the polyethylene layer was completely dissolved and removed in a benzene hot bath to obtain a recording disk. As in Example 5, the recording condition was good. Example 7 On a disk-shaped glass substrate with a thickness of 1 and a diameter of 30 arc, which has been thoroughly polished, a 2S3 layer is deposited to a thickness of about 0.0mm by vacuum evaporation.
3 was used as a forming medium.

Next, heat mode recording was performed using the apparatus used in Example 1. Thereafter, the glass plate was etched for about 5 seconds with 10% hydrofluoric acid (to a depth of about 0.3 French), and then all three Kinu layers were dissolved and removed by alkali etching. The recording bits and the surface of the recording medium were in very good condition. In addition, as a heat mode layer, QS, Bi2S3, A
When s2S3 was selected and recorded, similarly good recording was achieved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic structure of the recording medium of the present invention;
FIGS. 2 and 3 are cross-sectional views showing one embodiment of the recording method of the present invention, and FIG. 4 is an explanatory view showing a counterfeit device used for recording. In the drawings, 1 is a substrate, 2 is an information recording layer to be etched, 3 is a heat mode layer, 4 is a scattering of the heat mode layer, 5 is a raised part around the removed part, 6 is a laser beam, and 7 is information recording bits, 8 is a glass plate, 9 is a heat mode layer, 10 is a scattering object caused by heat mode, 11
is the rising capital around the removal part, 12 is the recording bit, 1
3 is an argon ion laser, 14 is a video signal, 15
16 is a light modulator, 16 is a reflecting mirror, 17 is a condensing lens, 18 is a beam, 19 is a mirror, 20 is a driving motor, and 21 is a recording medium. rwa " Rare drawings Figure 3 Figure 2 Figure 4

Claims (1)

[Claims] 1 A step of selectively irradiating an energy beam onto a recording medium having a heat mode layer and a recording layer to be etched, and selectively removing the heat mode layer with the heat generated by the energy beam, using the heat mode layer as an etching mask to remove the recording layer. A heat mode recording method comprising a step of etching away an exposed portion of the layer, and a step of removing a remaining heat mode layer.