JPS6098535A - Optical recording carrier and its production - Google Patents

Abstract

PURPOSE:To reduce D.O. at the production of a master disc by irradiating finely condensed light flux from the side of the 2nd thin film layer consisting of a heat sublimating material, opening a fine signal by heating action and then executing plasma etching by using the opened fine signal as a mask. CONSTITUTION:Laser light flux 10 is condensed to the 2nd thin film layer 7 consisting of the heat sublimating material on a recording carrier by an objective lens 9. The heat sublimating thin film layer 7 is easily sublimated by laser light flux 11, so that signal bit holes 8 have extremely sharp and fine edges respectively and the pit width 12 and the pit signal length 13 are also precise. For instance, calcogenide amorphous such as Ag, Cu or those compounds is proper to the sublimating thin film player 7. On the other hand, a material having low heat transmittivity and a high etching ratio in specific plasma gas is proper to the 1st film layer 6. The 1st thin film layer 6 is etched by plasma etching while using the sublimating thin film layer 7 as the mask pattern to obtain signal uneven patterns 14.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an optical record carrier capable of obtaining a concave-convex relief pattern, particularly an optical record carrier suitable for producing a glass manutar master, and a method for producing the same.

Conventional configurations and problems Disk systems include video discs, compact discs, and discs.
d after write) system, etc. The Dinuk carrier used in these disk systems can be easily produced from one stamper to a large number of replicated replica tissues by using a replica process such as injection.

video disc, video in the case of a compact disc,
A reflective film such as human β is attached to a replica made from a master disc on which digital signals are recorded, and a completed disc is created. On the other hand, in the case of a glass master master disk used in the D, R, A, W system, as shown in Figure 1, there is an address signal section 1 that normally displays the address, and an address signal section 1 that is necessary for stably recording the signal on the recording material. A groove 2 for R, person, and W is formed.

Te 0x (
0<X<2), an optical recording material such as TeC-TbFe is deposited by vapor deposition or sputtering to form an optical recording disk. In actual use, signals are recorded on the optical recording material on the groove 2. 3 is the center hole. Figure 2 is I- of Figure 1.
Convex cross-sectional view of line I' The inventors of the present invention have conducted various studies and found that the error rate due to defects in duplicate disks [hereinafter referred to as dropouts (D, 0.)] is extremely high compared to that of stampers. It has been concluded that the correlation is high, and in order to obtain a high quality stamper, it is especially important to set 0. It is extremely important to produce a glass master with a small amount of damage. In any of the current disk systems, a disk stamper is manufactured by the process shown in FIG. First, a photoresist 4 is placed on a well-cleaned glass master 5 (shown in FIG. 2) as a spin code, and a laser beam (short wavelength light of 4600 nm or less) that is exposed to this photoresist is focused into a minute spot to form a photoresist. 4 and rotate this master at 900 to 1800 rpm.
A signal is exposed and recorded on the photoresist 4 according to ON-OFF of the irradiation light by irradiating the spot light while rotating it and sending the spot light or the glass master disk 6 to one outer circumference or inner circumference. Thereafter, a developing solution is applied to the recorded glass master disk, and development is performed thereby to obtain an uneven relief pattern on the photoresist 4.

The glass master master disc is sent to the next plating process,
Ni metsuki stamper (hereinafter simply referred to as stamper)
is manufactured, and a disk is copied using this stamper.

In this way, the disk system has a process that allows for mass duplication, which is one of its great advantages compared to systems such as video tape recorders, in which it is relatively difficult to duplicate soft tapes.

However, the disks used in the disk system have a relatively large number of various defects, and when expressed as an error rate, it is generally about 10-5 to 10-4. In this way, 0. At present, there are relatively many of them in the disk, so their use is extremely limited, especially in the case of D, R, A, and W systems. That is, at present, it is limited to applications for video signals or document files, where requirements for error rates are relatively modest, and cannot be used in systems such as computer memory where a high error rate is desired.

On the other hand, even in the case of both video and compact systems, the disc adhesiveness is 0. If this decreases, the yield of the entire disk process will naturally improve.

Now, during this process, especially 0. It is concluded that the processes related to the increase are the resinut coating process and the development process. Since both processes are wet processes, they are sensitively affected by the quality of the washing water and the surrounding environment. In addition, since the photoresist film is weak and difficult to clean thoroughly, we have changed this process to a dry process that does not use water and is relatively unaffected by the surrounding environment. 7
) D, (It was strongly desired to lower make a record,
At this time, CH4 gas is generated due to thermal action, and a method has been announced that takes advantage of the fact that this gas is trapped in the film to produce a glass master with an uneven signal relief pattern without a developing process ( 1213, 1214, 1215) convex, but this method is especially effective at creating deep uneven grooves (more than 6008). Even a concavo-convex pattern with groove depth cannot be easily produced.

Another method is to directly adhere a metal or amorphous recording material to the required thickness on a substrate, and irradiate it with a recording spot light, making use of the sublimation property of thermal action to form a recording film. Attempts have been made to directly form a signal concavo-convex pattern.

However, in this case, the signal hole is created directly in the thick recording film, so the recording light power is about 5 J/af.
・While high power is required, as shown in Figure 4a, if the recording film is thick, heat diffusion occurs and perfect sublimation recording is not possible, so the signal hole 14 has an extremely poor edge T, so glass 1 as a bit signal hole for master disc
It was extremely inappropriate.

OBJECT OF THE INVENTION The present invention has been made to overcome the above-mentioned drawbacks.Since all steps or development steps are done in a dry manner, there is no need for glue or 0.0% during master production. It is an object of the present invention to provide an optical record carrier in which it is possible to significantly reduce the power of the recording light, and on which signals can be recorded even with a smaller recording light power.

DESCRIPTION OF THE INVENTION The invention is a record carrier in which there is a first thin film layer on a substrate and on top of this a second thin film layer of a thermal sublimation material. Then, in the method of the present invention, a minute signal is generated in the second thin film layer by thermal action by irradiating the second thin film layer with a slightly narrowed light beam, and then the second thin film layer is heated. This method of manufacturing a record carrier is characterized in that an uneven relief signal pattern is formed on the first thin film layer by performing plasma etching using the thin film layer as a mask.

Particularly when the first thin film layer is chalcogen-based amorphous, λg, Cu or a compound thereof is used as the second metal layer - after making a signal hole in this second thin film layer - 50
After photodoping the second thin film layer with Mug, Cu, or their compounds by irradiating with a short wavelength light beam of 00 Å or less, a concavo-convex relief signal pattern is formed in the chalcogen-based amorphous by plasma etching. You can also do that.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the optical record carrier according to the invention is shown in FIG. 5 and will be explained in detail below with reference to this figure.

FIG. 5a shows a pattern of recording a signal on a record carrier according to the present invention. 05 is a substrate, 6 is a first thin film layer, 7 is a second thin film layer made of a thermally sublimable material, and 8 is a recording signal bit. hole, 9
10 is an objective lens, 10 is a laser beam, and −11 is a focused laser beam. The laser beam 10 is directed by an objective lens 9 to a second thin film layer (hereinafter simply referred to as a sublimable thin film layer) made of a thermally sublimable material on the recording carrier. This sublimable thin film layer 7 is very thin, e.g.
Since it has a film thickness of Å or less, it is easily sublimated by the focused laser beam 11, and compared to the case where a metal etc. of the required thickness is directly sublimated by laser light as described above, the fourth As shown in the figure, the hole 8 of the signal bit is formed to be very sharp and has good etching, and the pit width 12 and bit signal length 13 are also accurate. Note that the first thin film layer 6 that holds the base carrier is preferably made of a material that does not undergo deformation due to this heat. Further, the sublimable thin film layer 7 should preferably have a melting point as low as possible and a bit edge that is as sharp as possible in view of the required recording light power. For example, A
9 or Aq compound, Cu or CU compound, Te or 'r
e compound, bismuth, 17 etc. metal abrasive - or AsS
Chalcogen amorphous materials such as e, 5eTe, 5eGe, TeOx, and TeC are preferable. On the other hand, the first thin film layer 6 has poor thermal conductivity and has a higher etching ratio (first thin film layer 6: sublimable thin film layer T) in a specific plasma gas than the sublimable thin film layer 7. good.

For example, when O2 waste is selected as the plasma etching waste, the first thin film layer 6 is made of an organic material (for example, jM,
ljA, Teflon, etc.) is preferable, and any material is effective for the sublimation/column layer. Further, chalcogen glass is used as the first thin film layer 6, and human q is used as the sublimable thin film layer 7.
Alternatively, in the case of using a chemical compound, OF4 is preferable as the plasma gas, and in the case where the sublimable thin film layer 7 is a Cu-based metal, it is preferable to use a gas such as CF4°CClF2 for etching. In either case, a sufficient etching ratio (1oo:1) can be obtained.

Therefore, if the first thin film layer 6 is about 1000 people,
100A is sufficient for the sublimable thin film layer.

FIG. 5 shows a state in which the first thin film layer 6 is etched by the above-mentioned plasma etching using the sublimable thin film layer 7 as a mask pattern, resulting in a signal unevenness pattern 14 of the required depth. .

What should be noted here is that if the first thin film layer 6 is etched under conditions that provide a sufficient selectivity,
Inevitably, a strong isotropic etching tendency appears. Therefore, when etching the first thin film layer 6 under the above conditions, in order to obtain the desired track groove width 12, the pit width 12 of the hole 8 must be smaller than the bit width of the pattern 14. It is desirable to form the groove width to be about twice as narrow as the film thickness of No. 6. A specific example is a signal groove with a groove width of 0.8 μm and a depth of 800 people (Tsukutan 1).
4) Consider the case of manufacturing a glass master master disk with a shape.

Now, if the substrate 5 is a glass master, the etching rate of SiO□ is usually very small compared to the etching ratio of the first thin film layer 6, no matter which of the etching gases mentioned above is used, so it can be ignored. I can do it.

However, OF4. When using CClF2 gas, the glass master may not be effective as a stop layer depending on the combination of the first layer material and the substrate glass material.

For example, etching residue OF4. There may be a combination of the first layer TeOx, etc. In this case, a metal layer Aβ, Or, Aq, Gu, etc. for the etching stop knob is formed on the glass substrate for 50 minutes so that the groove depth does not change due to the etching of the glass substrate.
It is preferable to use a material with numbers 08 to 10008 attached as the record carrier base.

Now, the thickness of the first thin film layer 6 is set to 800 mm, the thickness of the metal thin film layer 7 is set to about 70 mm, and a recording signal hole 8 with a width of 0.6 μm is formed in the sublimable thin film layer 7 using a recording laser beam. Afterwards, plasma etching can be performed to form the predetermined pattern 14, and a glass master having good bit edges can be manufactured. At this time, the longitudinal direction 13 of the signal is naturally affected by the side etching. Since the address signal recorded on discs for JR, A, and W is usually 1 μm or more, this effect can be ignored. If a signal length of 1 μm or less is to be recorded, it is possible to reduce both the width 12 and the longitudinal direction 13 by adjusting the optical recording power, which is a problem that can be easily solved. In some cases, a very accurate signal shape is required due to the problem of At this time, the sublimable thin film layer 7 is Aq or an Aq compound, C
As the first thin film layer 6, As2S3. As2Te3. Te0x(0(x<2)
Tea.

It is desirable to use a chalcogen-based amorphous material such as 5eGe. In this case, since amorphous glucogen generally has a lower melting point than metal, the upper layer of the amorphous thin film layer 6 is first vaporized by the recording light beam 11, and it blows away, for example, an Aq and Aq compound film of about 70 cm. Therefore, in this case, recording can be performed with a relatively lower recording light flux power (usually about 50 mJ/af) than when the first thin film layer 6 is an organic material, and with this recording power, the minute signal hole 8 can be formed in the metal thin film layer 7. It is possible to form accurately.

In this case, the main reaction is thermal reaction, and the so-called field wavelength light (50
Photodoping development in which Ag and Cu metals diffuse into chalcogen amorphous (less than 00 Å) is ignored because the irradiation time is usually less than μS. Therefore, there is no wavelength restriction for the recording light source, and it is possible to make clean signal holes in a metal thin film layer such as Aq.

Furthermore, as shown in Figure 6, before completing the above-mentioned and plasma etching, a short wavelength light beam 15 (of less than 50o○Å) (
For example, it is preferable to perform exposure while slowly rotating the record carrier under a well-parallelized light beam 17 formed by a lens 16 using a UJ lamp (3800 wavelength). At this time, the normal exposure time is set to about 2 minutes, and the exposure power is set to tsJ/arP. By adding such a step, photodoping development occurs in which the IG thin film 7 on the surface is doped into the chalcogen amorphous 6. That is, Aq is doped into the thin film 6 except for the pattern 14. After this, CF4. When the pattern 14 is formed by plasma etching in a gas atmosphere, side etching can be completely ignored and a well-focused pattern 14 can be obtained.

Now, the optical record carrier according to the invention can all be deposited on a base carrier with the same sputtering or vapor deposition device. - For example, when the first thin film layer 6 is a chalcogen-based amorphous, the substrate 5 is first placed in a Pelger of a vapor deposition device, and when a vacuum is created - the chalcogen-based amorphous is vapor-deposited to the required thickness by the IX1 heater, Then the second
A second boat is used to deposit metal such as Aq to the required thickness.
It is possible to form a thin film layer 7 of. In this way, since all the film preparation is done in vacuum, the optical record carrier's own glue is 0. can be rapidly reduced. or,
Since plasma etching, which corresponds to the development step, is also performed at low pressure, the glass master master shown in FIG. 1 can be completely produced by applying the present invention to a dry state.

On the other hand, when the first thin film layer 6 is an organic substance, it can be coated with a helium coater such as Teflon, or in some cases with a spinner coat. In the case of this spin code, although not everything is made dry, at least the developing process is made dry.

As mentioned above, it is possible to obtain an etch rate of 1:100 or more between the glass base carrier 5 and the first thin film layer 6.
The conditions for plasma etching (time, high frequency power, equipment) are sufficiently relaxed, and almost no etching unevenness has been observed. (Note that plasma etching in the present invention naturally includes reactive ion etching.
rn) Next, a specific example using the present invention will be shown.

Specific example 1 ○Record carrier Metal film 7: A (J film, 1008 film thickness, vapor deposition type.

First thin film 6: Teflon, 800, sputter format.

Base 5: BK7 glass.

○Recording optical power = 5mJ/CE! .

○Esoching gas 20□ ○Etching time: 1 minute (at 40OW high frequency input).

Specific example 2 0 record carrier Metal film 7: Ag film, 100 people, vapor deposition.

First thin film 6: j, M, M, A, , 800 people,
Spin code or plasma polymerization method formation.

Base 5: BK7 glass.

○Recording light power: 5mJ/nc+ ○Etching gas = 02 ( ○Etching time: 1 minute (when using 400W high frequency power).

Specific example 3 Metal film γ: Aq film, 50 people, vapor deposition.

First thin film e: As2S3. soo people, vapor deposition formation.

Base 5: BK7 glass.

○Recording optical power: 30 mJ/CXPr+○U, V,
Light 17 irradiation time: 2 minutes.

Hikari power knee 5J/af0 0 enoching gas 2CF4゜ Etching time = 1 minute (at 400W high frequency input).

Further, although the base carrier has been used as a glass base 6 from the beginning, other materials can also be used as the constituent material of the present invention as long as the plasma niche rate is lower than that of the first thin film layer 6. It is.

If the base plate 6 is made of acrylic only, the female fly will be etched by the 02 plasma and shattered. Therefore, a stopper nJ system (Sin2:
Metals, etc.) are thinly vapor-deposited (for example, metals such as fAl9
The thickness of the person β is not an issue. ) as a plate carrier, etching stops at the first material layer, so if a substrate 5 having such a structure with a metal layer formed thereon is used, the first thin film that also has optical transparency can be used. layer (e.g. P,)jM.

(person 9, etc.) to an appropriate thickness (for example, recording laser beam 1
If V4) with a wavelength of 0.00 is selected, the recording power to the sublimable layer 3 will be reduced, so the advantages of this will appear. ,D,0. is reduced to 10 to 10-7, the recording optical power is on the same level as conventional ones, record carriers with various characteristics can be constructed depending on the application, and the etching conditions are also extremely gentle. It became possible.

Note that the present invention is not limited to the production of master discs, but can be used for the production of various optical record carriers.

[Brief explanation of drawings]

Fig. 1 is a top view of the glass master master master for beam, R, person, W, Fig. 2 is a sectional view taken along line I-I' in Fig. 1, Fig. 3 is a conventional stambar manufacturing process diagram, Fig. 4 a and b are plan views of bit shapes in the conventional case with a thick recording layer and in the case of using the present invention; FIG. 5 a and b are manufacturing process diagrams of an optical record carrier according to an embodiment of the present invention; 1 is a process sectional view of another embodiment of the present invention in which a recorded optical record carrier is rotated and photodoped under a short wavelength light source. 0 1... address signal section, 2... empty groove,
5... Base carrier, 6... First thin film layer, 7... Second thin film layer consisting of sublimated moon phase, 8...
... Recording signal bit hole, 1Q ... Laser beam, 11 ... Narrowed down laser beam,
12...Pit width, 13...Bit signal length -14...Pattern, 15...U,
V, lamp, 17...Parallel light flux. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure 3 Figure 4 (OJ) (b)

Claims (1)

Scope of Claims: (1) A first thin film layer is formed on the substrate, a second thin film layer made of a heat sublimable material is formed on the first thin film layer, and the first and second thin film layers are formed on the first thin film layer. 1. An optical record carrier characterized in that a concavo-convex relief signal pattern is formed on a second thin film layer. (2) Optical record carrier according to claim 1, characterized in that the substrate is made of a glass material (3) The first thin film layer is made of chalcogen-based amorphous, and the second thin film layer is made of a The optical record carrier according to claim 1, characterized in that it is made of Cu alone, three metals, or a compound of the metals. (4) By providing a first thin film layer on a substrate, providing a second thin film layer made of a thermally sublimable material on top of this, and irradiating the second thin film layer with a slightly focused beam of light. , said second
A method for manufacturing an optical record carrier, characterized in that after making minute signal holes in the thin film layer, plasma etching is performed to form signal holes in the first thin film layer to form a relief signal pattern. (5) Using a chalcogen-based amorphous as the first thin film layer and using Aq or Cu alone or a compound of the metal as the second thin film layer, after making a minute signal hole in the second thin film layer, 5. The method of manufacturing an optical record carrier according to claim 4, wherein the record carrier is irradiated with a light beam having a short wavelength of 5000 Å or less, and then plasma etching is performed.