JPH03171446A - Production of information recording medium - Google Patents

Abstract

PURPOSE:To form the information recording medium which decreases errors with high productivity by executing the formation of an underlying layer by using a sputtering device the inside wall surface of which is heated. CONSTITUTION:The sputtering device 1 is provided with a turning substrate support 4 and a target supporting base 5 in a chamber 3 enclosed by a wall 2 and the inside wall surface 6 of the wall 2 is so constituted that the wall surface is controlled by electric resistance heating elements 7a to 7c provided on the outside surface side of the wall 2 to a prescribed temp. The substrate 8 is mounted on the rear surface of the substrate support 4. A resin target 9 for forming the underlying layer is placed on the target supporting base 5. The resin for forming the underlying layer is sputtered as a target while the inside wall surface of the sputtering device is kept heated in such a manner, by which the underlying layer is formed on the surface of the substrate. Thus, the information recording medium which decreases the errors is formed stably with the high productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention J] The present invention relates to a method for manufacturing an information recording medium that can manufacture an information recording medium with few errors with high productivity.

[Technical Background of the Invention] In recent years, information recording media that use high energy density beams such as laser light have been developed and put into practical use. This information recording medium is called an optical disk, and can be used as a video disc, an audio disc, a large capacity still image file, and a large capacity computer disk memory.

The basic structure of such an information recording medium is a disc-shaped transparent substrate made of plastic, glass, etc., and a Bi, Sn. It has a recording layer made of metal or semimetal such as In, Te, Se, etc. Information is written (recorded) on an optical disk by, for example, irradiating the optical disk with a laser beam, and the irradiated portion of the recording layer absorbs the light and locally increases in temperature, resulting in physical damage such as pit formation. Information is recorded by causing a chemical change such as a change or phase change to change its optical properties. Reading (reproducing) information from an optical disc is also performed by irradiating the optical disc with a laser beam, and the information is reproduced by detecting reflected light or transmitted light that corresponds to changes in the optical characteristics of the recording layer. be done. Laser beam irradiation for writing and reading information on the optical disc is usually performed at a predetermined position on the disc surface.

In such information recording media, in order to improve the recording sensitivity and reduce the degree of deterioration of the CN ratio of the read signal over time, fluorine and carbon made from a fluororesin are contained between the substrate and the recording layer. It has been proposed to form a base layer made of an organic compound by sputtering (for example, JP-A-64-7348). However, the underlayer as described above has poor adhesion with the substrate, which can cause the recording layer to peel off or create holes in the underlayer when information is recorded, so it is difficult to further improve the sensitivity and signal quality of the information recording medium. In order to achieve this, it was necessary to increase the thickness of the underlying layer. However, when forming the base layer by sputtering as described above, there is no particular problem when forming the base layer over a long time with low power, but in order to increase productivity, it is necessary to form the base layer with high power and high speed. If the underlayer is formed in a short period of time, there is a problem in that as the number of batches in which the underlayer is formed increases, errors in the manufactured information recording medium gradually increase.

The reason for this is that as the batch process for shaping the base layer is repeated, the base layer forming resin gradually adheres to the inner wall surface of the sputtering device, and the resin that adheres to the inner wall surface has some effect on the shape of the base layer. This is thought to be because it gives . Therefore, in the manufacturing process of information recording media, it is necessary to interrupt the operation and frequently clean the sputtering device for forming the underlayer, which reduces the productivity of the information recording medium.

[Objective of the Invention] The present invention provides improved sensitivity and signal strength without causing deformation or peeling of the underlayer from the substrate during data recording even when the underlayer made of resin is formed with high power in a short time. The purpose of this invention is to provide a method for manufacturing information recording media that can stably manufacture information recording media with high quality and extremely few errors with high productivity. [Summary of the Invention] The present invention provides a method for manufacturing an information recording medium that includes forming a base layer made of resin on the surface of a disc-shaped substrate by sputtering, and then providing a recording layer on the base layer. A method for manufacturing an information recording medium, characterized in that formation of a geological layer is performed using a sputtering device that heats an inner wall surface.

Preferred embodiments of the method for manufacturing an information recording medium of the present invention are as follows. 1) The method for manufacturing the information recording medium, wherein the base layer is made of a fluororesin or a polyimide resin. 2) The method for manufacturing the information recording medium, wherein the base layer is made of a fluororesin. 3) The fluororesin is at least one selected from polytetrafluoroethylene, polyvinyl fluoride, polytrifluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polychlorotrifluoroethylene, and polycarbon monofluoride. The method for manufacturing the above-mentioned information recording medium, characterized in that it is made of resin.

4) The method for manufacturing the information recording medium, wherein the fluororesin is polytetrafluoroethylene.

5) Form the base layer on the inner wall surface of the device by 60 to 300
The above-mentioned method for producing an information recording medium, characterized in that it is carried out by sputtering using a sputtering device heated to a degree of noodle in the range of 0.

6) The method for manufacturing the information recording medium, characterized in that the underlayer is provided with a layer thickness of Zoo to 3000X, more preferably 300 to 2000X.

7) The method for manufacturing the above-mentioned information recording medium, wherein the recording layer contains Te that allows information to be recorded and/or reproduced by laser light.

8) The recording layer is... The method for manufacturing the above-mentioned information recording medium, characterized in that the recording layer contains Te and Se.

9) The recording layer has SeaTebMc (however, 0.02
≦a≦0.35, 0.50≦b≦0.98, O≦C≦0
．． 45, where M is Pb. In, Ge, S
, Sb. AsBf, Sn. AKI. , Ga, Tl, Zn
．． Cd, Au, Pt. Ag, Cu. Nf. Pd, Rh,
Cr. The above-mentioned information recording medium has a composition represented by (representing at least one metal selected from Mo, W and Ta).

10) The method for manufacturing the above-mentioned information recording medium, wherein the metal represented by Doki M is Pb.

11) On the recording layer containing Doki Te, at least one material selected from silicon dioxide, tin oxide, magnesium fluoride, titanium oxide, TeOx (1≦X≦2), zirconium oxide, and zinc oxide. The method for manufacturing the information recording medium described above, characterized by laminating layers of:

12) On the recording layer, TeC), (1.5≦X≦
2) The method for manufacturing the information recording medium described above, characterized by laminating layers consisting of the following.

13) The recording layer is capable of recording and/or recording information using a laser beam.
Alternatively, the method for producing the information recording medium described above, characterized in that it contains a reproducible dye.

14) The dye contained in the recording layer is a cyanine dye, an azulenium dye, a squarylium dye, a phthalocyanine dye, a pyrylium dye, a thiopyrylium dye, an indophenol dye, an indoaniline dye, or a triphenylmethane dye. The method for producing the above-mentioned information recording medium, characterized in that the information recording medium is made of one or more kinds of dyes selected from dyes based on pigments, quinone dyes, aminium dyes, diimmonium dyes, metal complex dyes, and the like.

15) The method for producing the information recording medium, wherein the recording layer further contains 0.001 to 0.2 mol part of a metal complex dye per 1 mol part of the -L dye or dye mixture.

tS) The above-mentioned information recording medium and its manufacturing method, characterized in that the thickness of the above-mentioned recording layer is in the range of 500 to 2000 mm.

17) The method for manufacturing the information recording medium, wherein the material of the substrate is polycarbonate, polyolefin, or cell cast polymethyl methacrylate.

[Detailed Description of the Invention] In the method for manufacturing an information recording medium of the present invention, first, a base layer made of resin is formed on the surface of a disc-shaped substrate by sputtering.

The substrate can be arbitrarily selected from various materials used as substrates for conventional information recording media. Examples of substrate materials from the viewpoint of substrate optical properties, flatness, workability, ease of handling, stability over time, and manufacturing cost include glass such as soda lime glass; cell-cast polymethyl methacrylate, and injection molded plastic. Acrylic resins such as methyl methacrylate; vinyl chloride resins such as polyvinyl chloride and vinyl chloride copolymers; epoxy resins; polyesters such as polyethylene terephthalate; polycarbonates and amorphous polyolefins. Among these, preferred are polymethyl methacrylate, polycarbonate, epoxy resin, amorphous polyolefin and polyethylene terephthalate, with polycarbonate being particularly preferred.

Further, on the substrate, pre-groups are provided for the purpose of tracking groups, or pre-pits are provided for the purpose of forming irregularities representing information such as address signals. The pregroup or prebit can be obtained by forming a pregroup layer on the surface of the substrate using a mixture of a monomer (or oligomer) such as an acrylic acid ester and a photopolymerization initiator, or by forming a pregroup layer on the surface of the substrate, or by forming a pregroup layer on the surface of the substrate using a mixture of a photopolymerization initiator and a monomer (or oligomer) such as an ester of acrylic acid, or by forming a pregroup layer on the surface of the substrate. In some cases, pregroups or prepits may be formed directly on the substrate surface depending on the shape.

In the present invention, a base layer made of a fluororesin is then formed on the surface of the substrate by sputtering. The present invention is particularly characterized in that the underlayer is formed using a sputtering device that heats the inner wall surface thereof.

Resins that can be used to shape the base layer include:
Preferred examples include resins such as fluorine-based ballast resin and polyimide. Among these, a particularly preferred resin for the base layer is a fluororesin. Examples of the fluororesin include polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and tetrafluoroethylene-hexafluoropropylene copolymer (FE).
P). Tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (
EPE), polyvinyl fluoride, poly, trifluoroethylene, polyvinylidene fluoride, polyhexafluoropropylene, polychlorotrifluoroethylene, and polydicarbon monofluoride. Particularly preferred is polytetrafluoroethylene. Further, as the polyimide, for example, one obtained by subjecting a polyamic acid obtained by reacting an acid dianhydride and a diamine to thermal ring closure or chemical ring closure is used. As the acid dianhydride, pyrome1l lift acid dianhydride, biphenyltetracarboxylic dianhydride, penzophenonetetracarboxylic dianhydride, etc. are used. As the diamine, 4.4°-diaminodiphenyl ether, 4,4°diaminodiphenyl sulfone, 4,4'-diaminodiphenylmethane, etc. are used. The sputtering equipment used to form the above-mentioned underlayer will be explained with reference to the attached drawings. FIG. 1 shows the main parts of a specific example of a sputtering apparatus that can be used to form an underlayer in the present invention.
It is a partial sectional view shown typically.

In FIG. 1, a sputtering apparatus 1 includes a rotating substrate support 4 and a target support 5 provided in a chamber 3 surrounded by a wall 2. The inner wall surface 6 of the wall 2 has an electric resistance heating element 7 provided on the outer surface side of the wall 2.
A, 7b, and 7c (temperatures can be adjusted independently) are configured so that heating can be controlled to a predetermined temperature. heating means for heating the inner wall surface 6 of the wall 2;
2? The heating element is not limited to the above-mentioned one, and may be an electric resistance heating element embedded inside the wall 2, or
A panel with an electrical resistance heating element embedded therein may be installed within the chamber 3, or a heating lamp may be installed within the chamber 3. Although the details of the sputtering apparatus are not shown in FIG. 1, it is constructed in the same manner as a conventional and well-known sputtering apparatus, except that a heating means for heating the inner wall surface 6 is provided. ．． A substrate 8 is attached to the lower surface of the substrate support 4, and a resin target 9 for forming a base layer is placed on the target support 5. In the present invention, the first rII
In addition to the equipment shown in J, any equipment conventionally used for sputtering resin onto a substrate to form an underlayer can be used, as long as it has been modified to heat the inner wall surface to the desired temperature. 2) Even a sputtering device like this can be used. For example, ion beam sputtering equipment,
Any of an RF glow discharge sputtering device, a DC glow discharge sputtering device, a magnetron sputtering device, etc. can be used.

In the present invention, the base layer is formed on the surface of the substrate by sputtering using the base layer forming resin as a target while heating the inner wall surface of the sputtering apparatus as described above.

The optimum heating temperature for the inner wall surface of the sputtering apparatus described above varies depending on the resin used, sputtering conditions, etc., but is generally 60°C.
Preferably, the temperature is in the range of ~300°C, in particular:
Preferably, the temperature is in the range of 80 to 200°C.

Generally, as sputtering power is increased and sputtering is performed at a higher speed and in a shorter time, it is necessary to raise the temperature of the inner wall surface of the sputtering apparatus. Note that, since the inside of the chamber 3 is maintained at a high vacuum, even if the temperature of the inner wall surface of the sputtering apparatus is increased, the substrate itself will not be adversely affected.

The sputtering conditions for forming the base layer in the present invention may be those known per se.

For example, when sputtering is performed using a magnetron sputtering device, a pressure of IX10-3 to 50X10-3 Torr, a power of 50 to 2000 W, and a target distance of 20 to 200 mm (7) are used. Nz. 02, Ne, Kr, X
e. It is preferable to carry out the process using a gas such as a mixture thereof.

The layer thickness of the base layer is preferably in the range of 100 to 3000×, particularly in the range of 300 to 2000×.

By the above method, the above-mentioned lower J1! ! Even if the process of forming layers in a short time with high power is repeated, errors in the obtained information recording medium do not increase as the number of the above steps increases, unlike in conventional methods. Recording media can be manufactured.

In the present invention, a recording layer is then provided on the underlayer formed as described in section 2 above.

One of the above recording layers is capable of recording and/or recording information using a laser beam.
Alternatively, a reproducible recording layer containing Te is provided.

The recording layer preferably contains Te and Se.

Furthermore, the recording layer has SeaTebMc (however, 0.0
2≦a≦0.35, 0.50≦b≦0.98, O≦C≦
The value is in the range of 0.45, and M is Pb, In, Ge,
S, Sb, As, Bf. Sn. A.M. Ga. Tl. Zn
．． Cd, Au. Pt, Ag. Cu. Ni. Pd. Rh,
Cr. It is preferable to have a composition represented by (representing at least one metal selected from Mo, W and Ta).

Furthermore, it is preferable that the recording layer has a composition represented by Sea Teb Pbc (where a, b, and C are as shown in ``2'').

On the recording layer of the information recording medium of the present invention, silicon dioxide,
Tin oxide, magnesium fluoride, titanium oxide, TeOx
(However, 1≦X≦2) It is preferable that layers made of either zirconium oxide or zinc oxide are laminated.

Among these materials, TeOx (where 1 5 X is a number within the range of l≦X≦2, especially 1.5≦
It is preferable that layers consisting of (preferably a number in the range of X≦2) are laminated.

Although the recording layer containing Te has particularly excellent recording sensitivity, deterioration in sensitivity over time tends to occur after the recording layer is formed. Although the durability is improved by incorporating Se compared to Te alone, it is not sufficient. M in the above general formula
When other metals are added, for example, they have the effect of increasing light absorption, improving reflectance, and improving the flatness of the surface of the recording layer, but no contribution to improving durability has been observed. do not have. When a layer made of TeOx (where l≦X≦2) is laminated on a recording layer containing Te, not only the durability improves but also the recording sensitivity hardly decreases (2 small pits are formed). It can become easier. By making it easier to form small pits in this way, the resolution of recorded information becomes higher, and the latitude, which represents the applicable range of recording power to obtain a high C/N, becomes wider. 6 Improvement in recording and reproducing characteristics can be seen. Furthermore, in terms of durability, the C/N ratio does not decrease even after repeated reproduction, and reading durability is improved.

The thickness of the recording layer is preferably in the range of 100 to 3000 J from the viewpoint of ease of writing information and reflectance.
Particularly preferred is a range of 200 to 1200X.

Further, the layer thickness of the layer made of T e O x etc. is 50 to 1
A range of 000X is preferable, particularly preferably <1OO~
The range is 500X.

The recording layer is formed on the substrate by a known method such as vapor deposition, sputtering, or ion plating using the recording layer material mentioned above. Similarly to the recording layer, the layer made of Teax or the like is formed on the substrate by a known method such as vapor deposition, sputtering, or ion plating.

The other recording layer is a recording layer containing a dye that allows information to be recorded and/or reproduced by laser light. 12. The dye described above is not particularly limited, and any dye may be used. For example, cyanine dyes, azulenium dyes, squalirium dyes, phthalocyanine dyes, pyrylium dyes, thiopyrylium dyes, indophenol dyes, indoaniline dyes, triphenylmethane dyes, quinone dyes, aminium dyes, Examples include diimmonium dyes and metal complex dyes. Preferably, cyanine dyes and phthalocyanine dyes can be mentioned.

Among these, semiconductor lasers that emit near-infrared light have been put into practical use as recording and reproducing lasers.
A dye that has a high absorption rate for light in the near-infrared region of 700 to 900 nm is preferable. Note that these dyes may be used alone or as a mixture of two or more. Further, when a cyanine dye is used, it is preferable to use the above metal complex dye, aminium dye, or diimmonium dye together as a quencher.

In that case, the quencher is 0.0% per mole part of total dye.
It is preferable to contain 0.001 to 0.1 mole part.

Formation of a recording layer containing the above-mentioned dye involves dissolving the above-mentioned dye and, if desired, a binder in a solvent to prepare a coating solution, then applying this coating solution to the substrate surface to form a coating film, and then drying. This can be done by - E as a solvent for preparing the dye coating solution, ethyl acetate,
Esters such as butyl acetate and cellosolve acetate, ketones such as methyl ethyl ketone, cyclohexanone, and methyl isobutyl ketone, halogenated hydrocarbons such as dichloromethane, l,2-dichloroethane, and chloroform;
Examples include ethers such as tetrahydrofuran, ethyl ether, and dioxane, alcohols such as ethanol, n-propanol, isopropanol, and n-butanol, amides such as dimethylformamide, and fluorinated solvents such as 2,2,3,3-tetrafluoropropanol. Can be done. These non-hydrocarbon organic solvents may contain hydrocarbon solvents such as aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, and aromatic l9 group hydrocarbon solvents, as long as the amount is within 50% by volume. Good too. The coating solution also contains antioxidants, UV absorbers, plasticizers,
Various additives such as lubricants may be added depending on the purpose. When a binder is used, examples of the binder include cellulose derivatives such as gelatin, nitrocellulose, and cellulose acetate, natural organic polymers such as dextran, rosin, and rubber, and polyethylene, polypropylene, polystyrene, polyisobutylene, etc. Hydrocarbon resins, polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride Vinyl resins such as polyvinyl acetate copolymers, acrylic resins such as polymethyl acrylate and polymethyl methacrylate,
Examples include organic polymeric substances such as polyvinyl alcohol, chlorinated polyolefins, epoxy resins, butyral resins, rubber derivatives, and initial condensates of thermosetting resins such as phenol/formaldehyde resins.

Application methods include spray method, spin coat 20 method, dip method, roll coat method, blade coat method,
Examples include a doctor roll method and a screen printing method. In order to form a good orientation state of the dye,
It is preferable to use the Subin coat method. When a binder is used as a material for a recording layer containing a dye, the ratio of the dye to the binder is generally 0. Ol~99%
(weight ratio), preferably 1.0 to 95% (
weight ratio).

A reflective layer made of metal is further provided on the dye recording layer. By providing a reflective layer, it is possible to obtain the effect of improving reflectance, improving S/N during information reproduction, and improving sensitivity during recording. The material for the reflective layer is Mg. Se. Y, Ti, Zr,
Hf, V. Nb. Ta. Cr. MoW. Mn. Re,F
e. Co. Ni. Ru, Rh. Pd, I r, Pt, C
u, Ag. Au, Zn. Cd, An, Ga, In, Si
, Ge, Te, Pb, Po, Sn. Mention may be made of metals and metalloids such as Bi. Furthermore, alloys such as stainless steel may be used. In the present invention, the temperature is 400°K.
It is preferable that a reflective layer made of a metal having a high thermal conductivity of at least Low/msk or higher is provided.

Thereby, heat generated when the dye recording layer is irradiated with laser light can be rapidly conducted to the reflective layer. Among these, Au, Ag, Cu, Pt, An, Cr, Ni and stainless steel are particularly preferred. These substances may be used alone, or in combination of two or more or as an alloy.

A protective layer may be provided on the recording layer as described above. The protective layer is preferably a laminate of a soft protective layer made of a soft resin material and a hard protective layer made of a hard resin material. This laminate is laminated on the recording layer with the soft protective layer side facing the recording layer side. Examples of the soft resin material include polyurethane, polyvinylidene chloride, ethylene/vinyl acetate copolymer, silicone rubber, styrene*butadiene*rubber, polyvinylidene chloride, and polyacrylic acid ester. Usually, these are applied onto the recording layer by methods such as solution coating, latex coating, and melt coating, and are subjected to treatments such as drying and heating as necessary to form a soft protective layer. The thickness of the soft protective layer is usually in the range of 100X to 5 JLm, preferably in the range of 0.3 to 3 JLm. Examples of hard resin materials include ultraviolet curing resins and thermosetting resins. Usually, these are applied onto a soft protective layer by a method such as solution coating, and if necessary, a treatment such as ultraviolet irradiation or heating is performed to form a hard protective layer. The thickness of the hard protective layer is usually 0.1 to 10Ii. m, preferably in the range of 1 to 3 ILm.

The surface of the substrate opposite to the side on which the recording layer is provided is coated with silicon dioxide, tin oxide, magnesium fluoride, and the above-mentioned T e O to improve scratch resistance, moisture resistance, etc.
A thin film made of an inorganic substance such as x, or a polymeric substance such as a thermoplastic resin or a photocurable resin may be provided by a method such as vacuum evaporation, sputtering, or coating.

2 3 Using the information recording medium manufactured according to the present invention, information can be recorded by an optical information recording method as described below. The information recording medium manufactured according to the present invention includes:
Since it is particularly suitable for recording CD format signals, this will be explained as an example.

First, while rotating the information recording medium at a constant linear speed of 1.2 to 1.4 m/sec, a recording light such as a semiconductor laser beam is applied from the substrate side having pregroups on the surface to the pregroups. CD by irradiating the group with laser light.
The formatted EFM signal is recorded by forming pits on the recording layer of the group. Generally, a semiconductor laser beam having an oscillation wavelength in the range of 750 to 850 nm is used as the recording light. Generally 3-15mW
recorded with a laser power of

As a result, the recording layer has a length of 0.70 to 4. OI1. m
The pits are formed concentrically or spirally at intervals of 0.70 to 4.0 JLm.

During recording, tracking control is performed using the tracking pre-group.

The recording of information according to the invention takes place in the bottom area of the group of the pregroup.

Information is reproduced by irradiating semiconductor laser light from the substrate side while rotating the recording medium at the same constant linear speed as above.
This can be done by detecting the reflected light.

Next, examples of the present invention will be described. However, these examples do not limit the invention.

[Example 1] Disc-shaped polycarbonate substrate with tracking grooves (outer diameter: 120 mm, inner diameter = 15 mm, thickness: 1.2
mm, inner diameter 46 mm to outer diameter 117 mmc7) A groove with a depth of 800X, a half width of 0.7 μm, and a pitch of 1.6 pm is provided in a spiral shape) using polytetrafluoroethylene on the surface. The temperature of the inner wall surface of the chamber of the magnetron sputtering apparatus as shown in FIG. Power 400W, target distance 90
The layer thickness was 12007 mm by sputtering for 10 minutes under the conditions of
The base layer was formed. Next, on this base layer, using a mixed target containing Te, Se and Pb of 78 atomic %: 18 M atomic % and 4 atomic %, respectively, sputtering gas: argon, pressure 5 mTorr, power 125 W, target} ffiJ190m
Sputtering was performed for 5 minutes under the conditions of m to form a recording layer with a thickness of 600 μm.

On this recording layer, Te02 was sputtered for 3 minutes under the conditions of sputtering gas: argon, pressure of 5 mm Torr, power of 100 W, and target distance of 90 mm, resulting in a layer thickness of 803 mm.
A layer of T e O of 1.6 was formed. In sputtering after forming the recording layer, the inner wall surface of the sputtering device was not particularly heated. In this way, an information recording medium consisting of a substrate, an underlayer, a recording layer, and a layer of TeOI, 6, was manufactured. Subsequently, the sputtering device for forming the base layer used in the production of the above information recording medium was used as it was without cleaning, and a second information record 8111 body was produced in the same manner as above, and the following was carried out in the same manner. , the production of the information recording medium was repeated a total of 5 times.

Wavelength: 7 for the information recording media manufactured in each of the above steps
80nm. NA: 0.5. EFM signals were recorded with linear velocity: 1.2 m/sec, laser power = 5.6 mW, and recording waveform: duty and pulse number correction.

The recorded signal is reproduced at wavelength: 780 nm, NA: 0.
．． 45, Linear velocity: 1.2m/sec, Laser power: 0.5
mW, and the CI error (numbers/second) at that time was measured.

Table 1 shows the errors for the information recording media manufactured each time.

[Comparative Example 11 In Example 1, an information recording medium was manufactured in the same manner as in Example 1, except that the inner wall surface of the sputtering device was not particularly heated during the formation of the underlayer.

Subsequently, the base layer sputtering equipment used in the production of the above information recording medium was used as it was without cleaning, and a second information recording medium was produced in the same manner as above. The production of the information recording medium was repeated five times in total.

Example 1 Regarding the information recording medium manufactured in each of the above steps,
The error was measured in the same manner as in.

The results are shown in Table 1. Table 1 As is clear from the results in Table 1, the information recording medium manufactured according to the present invention obtained in Example 1 showed an increase in the number of repetitions when the formation of the underlayer was repeated in the same device. However, the errors in the information recording medium obtained in Comparative Example 1 increased significantly as the number of repetitions increased. are doing.

[Advantageous Effects of the Invention 1] The method for manufacturing an information recording medium of the present invention makes it possible to shorten the time required to form the base layer by increasing the power when forming the base layer by sputtering, and to form the base layer under such conditions. Since the performance of the information recording medium manufactured does not deteriorate even if the information storage medium is damaged, the number of times required for maintenance and cleaning of the sputtering equipment for forming the base layer can be reduced, and information with stable performance can be obtained. This has the remarkable effect of not only making it possible to manufacture recording media but also significantly increasing the productivity of information recording media.

[Brief explanation of the drawing]

FIG. 1 shows the main parts of a specific example of a sputtering apparatus that can be used to form an underlayer in the present invention.
It is a partial sectional view shown typically. Reference Signs List 1: Spatter device, 2: Wall, 3: Chamber, 4: Substrate support, 5: Target support, 6: Inner wall surface, 7a, 7b, 7c: Electric resistance heating element, 8: Substrate, 9: Resin target.

Claims (1)

[Claims] 1. A method for manufacturing an information recording medium comprising forming an underlayer made of resin on the surface of a disc-shaped substrate by sputtering, and then providing a recording layer on the underlayer, the underlayer comprising: 1. A method of manufacturing an information recording medium, characterized in that the formation of the information recording medium is performed using a sputtering device that heats the inner wall surface. 2. The method for manufacturing an information recording medium according to claim 1, wherein the base layer is made of a fluororesin. 3. The method for manufacturing an information recording medium according to claim 1, wherein the recording layer contains Te that allows information to be recorded and/or reproduced by laser light.