JP2536819C - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION   I Background of the Invention   Technical field   The present invention is a magneto-optical device for recording and reproducing information using heat and light such as laser light.
The present invention relates to an optical recording medium such as a recording medium.   Prior art and its problems   As one of the optical recording media, there is a medium for a magneto-optical memory.   As a recording medium of a magneto-optical memory,   MnBi, MnAlGe, MnSb,   MnCuBi, GdFe, TbFe,   GdCo, PtCo, TbCo,   TbFeCo, GdFeCo,   TbFeO_Three, GdIG, GdTbFe,   GdTbFeCoBi, CoFe_TwoO_Four   Such materials are known. These are methods such as vacuum evaporation and sputtering.
Thus, a thin film is formed on a transparent substrate such as plastic or glass. These lights
Characteristics common to magnetic recording media include:   The axis of easy magnetization is perpendicular to the film surface,   In addition, the car effect and the Faraday effect are large.   What is required of such a medium is   First, the Curie point should be around 100-200 ° C and the compensation point should be around room temperature.
When,   Second, there are relatively few defects such as grain boundaries that cause noise.   Third, a magnetically and mechanically uniform film can be obtained over a relatively large area.
can give. In response to such demands, among the above materials, in recent years, rare earth-transition gold
Amorphous perpendicular magnetic thin films of the genus have attracted great attention.   However, a magneto-optical recording medium composed of such a rare earth-transition metal amorphous thin film is not used.
When the magnetic thin film layer is stored in contact with the atmosphere, it is diluted by oxygen and water in the atmosphere.
Earth is selectively corroded or oxidized, making it impossible to record and reproduce information.
You. Further, in order to improve the recording / reproducing characteristics and further improve the C / N ratio, recording is performed.
-It is necessary to increase the rotation angle during reproduction as much as possible.   Therefore, generally, a protective layer is provided on the surface of the magnetic thin film layer on the substrate side or on the side opposite to the substrate.
Many having the provided configuration have been studied.   Conventionally, to provide corrosion resistance such as moisture proof or multiple interference to Kerr effect
In order to increase the rotation angle by adding the effect of
Inorganic materials such as silicon oxide, silicon dioxide, aluminum nitride, silicon nitride, and zinc sulfide It is well known to provide an empty deposition film or the like (Japanese Patent Application Laid-Open No. 58-80142).   However, none of them is still satisfactory in terms of corrosion resistance and the like.   Further, as a material of the intermediate layer, a mixture of an oxide and a nitride, in particular, Si_ThreeN_FourAnd S
iO_TwoWith Si,_ThreeN_FourAnd SiO_TwoOr a mixture of AlN and Al_TwoO_ThreeMixed with
It is also known to use a compound (JP-A-60-145525).   However, this is not sufficient in terms of C / N ratio or corrosion resistance.   In addition, the present inventors have disclosed in Japanese Patent Application No. 61-307300 that an intermediate layer has two or more types.
Contains metal and metalloid nitrides and oxides, such as Si, Al, N and O
We propose to use a material that does the same as the intermediate layer.   However, this is not sufficient in terms of C / N ratio, corrosion resistance and the like.   Further, the refractive index is 2.1 or more with silicon nitride as the main component as the intermediate layer.
One containing additional components (Japanese Patent Application Laid-Open No. 61-22458), silicon nitride and oxidized
Sputtered target containing aluminum and yttrium oxide
And the like (Japanese Patent Application Laid-Open No. 61-278062).   These intermediate layers are Si, Al, N and O, yttrium, lanthanoid
When it contains at least one of an element and an actinoid element
Are satisfactory in terms of recording / reproduction characteristics and C / N ratio.   However, the specific composition of the intermediate layer described in JP-A-61-22458
Is Si_ThreeN_Four 90mol% -Al_TwoO_Three 6mol% -Y_TwoO_Three 4 mol%
, Si + N is 92.6 at%. Further, Japanese Patent Application Laid-Open No. 61-278062 discloses
Interlayer composition is Al_TwoO_Three 0.1-5 mol%, Y_TwoO_Three 0.1-3 mol%, Si_Three
N_Four 92 to 99.8 mol%, and Si + N is 94.2 at% or more. this
Therefore, these intermediate layers have a large film stress, and are repeatedly formed with the same apparatus.
When this occurs, the film substance adhering to the inner wall of the device is peeled off and adheres to the medium.
There are drawbacks such as formation of pinholes during film formation.   Furthermore, these intermediate layers have a low light transmittance, so that a sufficient amount of reflected light cannot be obtained.
This causes loss of the raw signal amount and instability of the reproduction system due to loss of the servo signal.   Incidentally, such a problem is caused by an optical recording medium having a so-called phase transition type recording layer.
But the same is true.   II Purpose of the Invention   An object of the present invention is to achieve stable recording / reproducing characteristics, a good C / N ratio and good corrosion resistance, and
Another object of the present invention is to provide an optical recording medium free from warpage of a substrate and pinholes in an intermediate layer.   III Disclosure of the Invention   Such an object is achieved by the present invention described below.   That is, the first invention of the present invention has a recording layer on a substrate, and the recording layer and the substrate
In an optical recording medium having an intermediate layer between the silicon and the aluminum,
And Y and lanthanoid elements (La, C
e, Pr, Nd, Sm and Eu) in the intermediate layer.
Content of at least one of, yttrium and lanthanoid elements is 0.1at%
Not less than 2 at% and the total content of silicon and nitrogen is 20 to 65 at%.
An optical recording medium characterized by the following.   Further, the second invention has a recording layer on a substrate and an intermediate layer between the recording layer and the substrate.
Optical recording medium having a protective layer between a substrate and an intermediate layer and / or on a recording layer
In the above, the intermediate layer contains silicon, aluminum, oxygen and nitrogen.
And yttrium and lanthanoid elements (La, Ce, Pr, Nd, S
m and Eu), and yttrium and
Content of one or more of the lanthanoid elements and lanthanoid elements is at least 0.1 at% and less than 2 at%;
Wherein the total content of silicon and nitrogen is 20 to 65 at%.
It is a recording medium.   IV Specific Configuration of the Invention   Hereinafter, a specific configuration of the present invention will be described in detail.   One embodiment of the magneto-optical recording medium of the optical recording medium of the present invention is shown in FIG.   In FIG. 1, a magneto-optical recording medium 1 of the present invention has an intermediate layer 4 on a substrate 2.
And a magnetic thin film layer 5 as a recording layer thereon.   In the second invention, the protective layer is provided between the substrate and the intermediate layer and / or on the recording layer. 31 and 35.   Such an intermediate layer 4 of the present invention comprises silicon, aluminum, oxygen and nitrogen.
And one or more of yttrium and lanthanoid elements.
It contains.   Good durability and corrosion resistance are exhibited by containing these elements.
As a result, the recording and reproducing characteristics and the C / N ratio are also excellent. Also, in this case,
If even one of the essential elements is missing, the effect of the present invention will not be realized.   In the intermediate layer of the present invention, the total content of silicon and nitrogen, ie, Si + N is 20 to 6
5 at%. If this total is less than 20 at%, the refractive index will be low and the enhancement effect will be obtained.
When the result exceeds 65 at%, the film stress increases and the use of a forming apparatus
Repeated times generate dust in the vacuum chamber, pinholes in the intermediate layer, and light transmission
As the reflectivity decreases, the reflectivity decreases, the servo signal decreases, and stable
This is because there is a drawback that it is difficult to obtain a disk. Also, Si + N is 20 to 65.
At% is preferred in terms of light transmittance.   Further, the content of aluminum is 3 to 33 at%, more preferably 3 to 25 at%.
is there. At this time, the film quality is stable and dense, and the corrosion resistance is improved.   The content of Si should be 8 to 40 at%, more preferably 8 to 36 at%.
Is preferred. In the intermediate layer, silicon and aluminum are usually
Contained in the form of oxides and nitrides to form amorphous.   These compounds may be out of stoichiometric composition in their composition.
.   In the intermediate layer of the present invention, the above-mentioned amorphous, yttrium and lanthanoid
Contains one or more of the elements. To contain these elements less than 2at%
It is possible to increase the refractive index without impairing the reflectance, and improve the recording sensitivity.
Can be   By containing these, recording sensitivity and C / N ratio become better.
.   In the present invention, the lanthanoid element includes yttrium (Y), lanthanum (La)
), Cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium At least one element selected from the group consisting of (Sm) and europium (Eu)
is there. By using these, only recording and reproduction characteristics such as recording sensitivity and C / N ratio
This is because better results can be obtained in terms of durability, corrosion resistance, and the like.   In addition, when obtaining a sintered compact target, these yttrium and lanthanoid sources are used.
By including at least one element, a more precise target can be obtained.
As a result, the cooling efficiency of the target is improved and the radiant heat during sputtering is suppressed.
You.   One or more of these yttrium and lanthanoid elements (hereinafter referred to as R
Is mixed with the above-mentioned amorphous material in the intermediate layer.
Alternatively, it may be contained in any form of the compound. When contained as a compound
, Usually in the form of an oxide.   The content of one or more yttrium and lanthanoid elements in the intermediate layer is:
It is preferably at least 0.1 at%, particularly 0.2 to 1.9 at%. 0.1at% not yet
If it is full, there is no effect of the present invention.   The content of each element in the intermediate layer is determined by Auger, ESCA, SIMS, LAM
What is necessary is just to measure by MA etc.   In addition, such an intermediate layer can be formed by various vapor deposition methods, for example, a sputtering method, an evaporation method,
The layer is formed by an ion plating method, plasma CVD, optical CVD, or the like. Special
It is preferable to use a sputtering method, and in this case, it corresponds to the composition to be formed.
Sputtering method using a target, using a target composed of two or more different compositions
Multi-source sputtering, reactive sputtering using oxygen and nitrogen, etc.
It is formed.   And, in particular, of the above-mentioned vitreous and yttrium and lanthanoid elements
It is preferable to use a multi-source sputtering method using at least one of the above as a target.
  The thickness of such an intermediate layer is 30 to 300 nm, particularly 50 to 200 n.
m is preferable.   Further, the film thickness is set to λ / 4n (where λ is the laser wavelength used and n is the refractive index of the intermediate layer).
When specified, a more favorable result is obtained in terms of the enhancement effect.   Further, Ar, N existing in the film formation atmosphere as impurities in the intermediate layer are used._TwoEtc. You may.   Other, Fe_TwoO_Three, CuO, Cr_TwoO_Three, MnO_x, CoO, NiO, As_TwoO_Three
Etc. may be contained in an amount of about 1.0% by weight or less of the whole.   The magnetic thin film layer 5 used as a recording layer in the present invention is a modulated heat beam.
Or the information is magnetically recorded by a modulated magnetic field.
It reproduces the data by performing magneto-optical conversion.   The material of the magnetic thin film layer 5 is preferably a rare earth metal such as Gd or Tb.
Alternatively, an alloy of a transition metal such as Fe or Co is formed into an amorphous film by sputtering, vapor deposition, or the like.
It was formed. In this case, the total content of Fe and Co is 65 to 85 at%.
Preferably, there is.   The balance is substantially a rare earth metal, especially Gd and / or Tb.   As preferable examples thereof, TbFeCo, GdFeCo, GdTbFeC
O and the like.   Further, a part of Gd and / or Tb is replaced with Sm, Nd, Dy, Eu, Pr, C
e, substitution of at least 50 at% with one or more of Ho is more favorable in terms of recording sensitivity.
Good results are obtained. Note that, in these magnetic thin film layers, C
r, Al, Ti, Pt, Si, Mo, Mn, V, Ni, Cu, Zn, Ge, Au
Etc. may be contained.   Further, Sc, Y, La, Ce, Pr,
Nd, Pm, Sm, Eu, Dy, Ho, Er, Tm, Yb, Lu, etc.
Good.   The thickness of such a magnetic thin film layer is usually about 10 to 1000 nm.   In addition, as a material of the recording layer, as a so-called phase transition type, for example,   Te-Se, Te-Se-Sn, Te-Ge, Te-In, Te-Sn, Te
-Ge-Sb-S, Te-Ge-As-Si, Te-Si, Te-Ge-Si
-Sb, Te-Ge-Bi, Te-Ge-In-Ga, Te-Si-Bi-Tl
, Te-Ge-Bi-In-S, Te-As-Ge-Sb, Te-Ge-Se-
S, Te-Ge-Se, Te-As-Ge-Ga, Te-Ge-S-In, Se
-Ge-Tl, Se-Te-As, Se-Ge-Tl-Sb, Se-Ge-Bi , Se-S (above, Japanese Patent Publication No. 54-41902, Patent No. 1004353, etc.)
  TeO_x(Te oxidation described in JP-A-58-54338 and JP-A-974257.
Te) dispersed in the material   TeO_x+ PbO_x(Japanese Patent No. 974258),   TeO_x+ VO_x(Japanese Patent No. 974257), other, Te-Tl, Te-Tl
-Si, Se-Zn-Sb, Te-Se-Ga, TeN_xMainly Te, Se, etc.
Chalcogen   Alloys that cause an amorphous-crystalline transition, such as Ge-Sn and Si-Sn   Color change due to crystal structure change of Ag-Zn, Ag-Al-Cu, Cu-Al, etc.
And alloys such as In-Sb that cause a change in crystal grain size.   Such a recording layer is formed by a deposition method, a sputtering method, an ion plating method or the like.
What is necessary is just to set up using an coating method etc. And its thickness is 20nm ~
It is about 1 μm.   The substrate 2 is made of glass or resin, and is preferably made of acrylic resin.
Resin, polycarbonate resin, epoxy resin, polymethylpentene resin, etc.
I can do it.   Among these resins, polycarbonates are used in terms of durability, especially resistance to warpage, etc.
Nate resins are preferred.   As the polycarbonate resin in this case, aliphatic polycarbonate, aromatic
-Aliphatic polycarbonate, aromatic polycarbonate may be any
It is particularly preferable to use an aromatic polycarbonate resin. Of these,
Polycarbonate resin from bisphenol is preferred in terms of point, crystallinity, handling, etc.
Good. Among them, bisphenol A type polycarbonate resin is most preferable.
Used.   The number average molecular weight of the polycarbonate resin is 10,000 to 15,000.
It is preferred that it is about.   The refractive index at 830 nm of such a substrate 2 is usually about 1.55 to 1.59.   Since the recording is performed through the substrate 2, the recording or reading light
The transmittance is 86% or more.   A tracking groove is formed on the surface of the disk-shaped substrate on which the magnetic thin film layer is formed.
May be performed.   The depth of the groove is about λ / 8n, particularly λ / 6n to λ / 12n (where n is
Index of refraction). The width of the groove is set to about 0.4 to 2.0 μm.   Further, a pit for an address may be formed.   Then, usually, the magnetic thin film layer located in the concave portion of the groove is used as a recording track portion,
It is preferable to irradiate the writing light and the reading light from the back side of the substrate.   With this configuration, the writing sensitivity and the C / N ratio for reading are improved.
In addition, the tracking control signal becomes large.   Further, other shapes of the substrate may be tapes, drums, and the like.   According to the second aspect of the present invention, protection is provided between the intermediate layer and the substrate and / or on the recording layer.
It has layers 31 and 35. At this time, the durability and corrosion resistance as a medium are more preferable.
It becomes   The material of such protective layers 31 and 35 includes oxygen, carbon, nitrogen, sulfur and the like.
Compounds such as SiO_Two, SiO, AlN, Al_TwoO_Three, Si_ThreeN_Four, ZnS,
BN, TiO_TwoVarious dielectric materials such as, TiN, etc. or a mixture thereof; glass
For example, borosilicate glass, barium borosilicate glass, aluminum borosilicate
Acid glass or the like_ThreeN_FourEtc. may be used. Inside
But SiO_Two 40-80 wt% borosilicate glass, barium borosilicate glass
, Aluminum borosilicate glass and these SiO_TwoPart of Si_ThreeN_FourEtc.
What is replaced is preferable.   Of these, particularly preferred are the following.   (1) 40-60 wt% of silicon oxide, BaO, CaO, SrO, MgO, Zn
50% by weight or less of divalent metal oxides such as O and PbO and / or alkali metal oxides
Containing not more than 10 wt% and boron oxide and / or aluminum oxide
.   (2) Si, Ba, Ca, Sr, Mg, Zn as another metal or metalloid element
, Pb, etc., one or more Al, B, and one or more alkali metal elements.
Including at least one of the above, wherein the atomic ratio of Si in all metals or metalloids is 0.3 to 0.9 and further contains O and N, and O / (O + N) is 0.4 to 0.8.
Things.   These are disclosed in Japanese Patent Application Nos. 61-300859, 61-302275, and 61-301.
No. 303224, No. 61-307300, No. 61-313614, No. 61-
No. 313615, No. 61-314949, No. 61-314948, No. 61-
No. 313720 and the like.   When the above is used, durability and corrosion resistance are more excellent. Also,
The method of forming the protective layers 31 and 35 as described above may be performed according to the method of the intermediate layer 4.
The thickness is preferably about 30 to 300 nm, particularly preferably 50 to 200 nm.
.   Usually, an organic protective coat layer 6 is provided on the protective layer 35.   As the material of the organic protective coat layer 6, various known organic substances are usually used.
Just do it.   More preferably, the radiation-curable compound is cured by radiation such as electron beam, ultraviolet light, etc.
It is better to use   The radiation-curable compound used is sensitive to ionization energy,
Acrylic acid or methacrylic acid having an unsaturated double bond exhibiting polymerizability, or it
Acrylic double bond such as ester compounds, diallyl phthalate
Radiation of unsaturated double bonds such as allylic double bonds, maleic acid and maleic acid derivatives
Monomers containing or introduced in the molecule crosslinkable or polymerizable groups by irradiation
, Oligomers and polymers.   As the radiation-curable monomer, a compound having a molecular weight of less than 2000 may be an oligomer.
Used are those having a molecular weight of 2,000 to 10,000.   These are styrene, ethyl acrylate, ethylene glycol diacrylate
, Ethylene glycol dimethacrylate, diethylene glycol diacrylate
, Diethylene glycol methacrylate, 1,6-hexane glycol diacrylate
And 1,6-hexane glycol dimethacrylate, etc., are also particularly preferred.
There are pentaerythritol tetraacrylate (methacrylate),
Pentaerythritol acrylate (methacrylate), trimethylolpropa Triacrylate (methacrylate), trimethylolpropane diacrylate
(Methacrylate), polyfunctional oligoester acrylate (Aronix M-
7100, M-5400, M-5500, M-5700, M-6250, M-6
500, M-8030, M-8060, M-8100, etc., Toagosei), urethane
Acrylic modified elastomer (Nipporan 4040) or these
To which a functional group such as COOH is introduced, and phenol ethylene oxide adduct
Acrylate (methacrylate), pentaerythritol represented by the following general formula
Acrylic group (methacrylic group) or ε-caprolactone-acrylic group
Compound   1) (CH_Two= CHCOOCH_Two)_Three-CCH_TwoOH                                   (Special acrylate A)   2) (CH_Two= CHCOOCH_Two)_Three-CCH_TwoOH_Three                                   (Special acrylate B)   3) [CH_Two= CHCO (OC_ThreeH₆)_n-OCH_Two]_Three-CCH_TwoCH_Three                                   (Special acrylate C)   In the formula, a compound of m = 1, a = 2, b = 4 (hereinafter referred to as special pentaerythritol-
Compound A), Compounds with m = 1, a = 3, b = 3 (hereinafter referred to as special pentaerythritol condensate B
A), m = 1, a = 6, b = 0 (hereinafter, special pentaerythritol-condensed)
Compound C), a compound of m = 2, a = 6, b = 0 (hereinafter referred to as a special pentaerythritol condensate D
Say), And special acrylates represented by the following general formula.   8) CH_Two= CHCOO- (CH_TwoCH_TwoO)_Four-COCH = CH_Two                                   (Special acrylate H)   Further, as the radiation-curable oligomer, a polyfunctional oligomer represented by the following general formula is used.
Modified acrylic of ester acrylate or urethane elastomer or this
These include those in which a functional group such as COOH is introduced.   In addition, radiation-curable type obtained by radiation-sensitive modification of thermoplastic resin
Compounds may be used.   Specific examples of such a radiation-curable resin include an unsaturated polymer having radical polymerizability.
Acrylic acid, methacrylic acid, or their ester compounds showing a double bond
Acrylic double bond such as, allyl double bond such as diallyl phthalate,
Cross-linking due to irradiation of unsaturated bonds such as maleic acid and maleic acid derivatives
Or a resin in which a polymerizable group is contained or introduced into the molecule of the thermoplastic resin.   Examples of thermoplastic resins that can be modified into radiation-curable resins include vinyl chloride copolymers.
Coalescence, saturated polyester resin, polyvinyl alcohol resin, epoxy resin
And phenoxy resins, cellulose derivatives and the like.   Other resins that can be used for radiation-sensitive modification include polyfunctional polyesters.
Ter resin, polyetherester resin, polyvinylpyrrolidone resin and derivatives
(PVP olefin copolymer), polyamide resin, polyimide resin, phenol
Resins, spiroacetal resins, hydroxyl-containing acrylic esters and methacrylates
Acrylic resins containing at least one kind of lyl ester as a polymerization component are also effective.
.   The thickness of the organic protective coating layer 6 of such a radiation-curable compound is 0.1 to 30 μm.
m, more preferably 1 to 10 μm.   If the thickness is less than 0.1 μm, a uniform film cannot be formed, and The moisture-proof effect in the air is not sufficient, and the durability of the magnetic thin film layer 5 is not improved. Also, 3
If the thickness exceeds 0 μm, warpage of the recording medium or a protective layer due to shrinkage due to curing of the resin film.
Cracks occur in the inside, making it unsuitable for practical use.   Such coatings are usually spin-coated, gravure-coated, spray-coated,
The layers may be formed by a combination of various known methods such as chipping. The paint film at this time
The layering conditions are appropriately determined in consideration of the viscosity of the mixture of the coating composition, the target coating thickness, and the like.
You only have to decide.   In order to cure such a coating film to form a protective layer, radiation such as electron beams, ultraviolet rays, etc.
The coating may be irradiated.   When an electron beam is used, the radiation characteristics include an acceleration voltage of 100 to 750 KV and a good radiation characteristic.
Preferably, use a radiation accelerator of 150 to 300 KV and reduce the absorbed dose to 0.5 to 20
It is convenient to irradiate so as to be gallads.   On the other hand, when ultraviolet rays are used, some of the radiation-curable compounds described above
Usually, a photopolymerization sensitizer is added.   As the photopolymerization sensitizer, conventionally known photosensitizers may be used.
Ether, benzoin ethyl ether, α-methylbenzoin, α-chlordeo
Benzoin series such as xybenzoin, benzophenone, acetophenone, bisdia
Ketones such as rukylaminobenzophenone, anthraquinone, phenanthraquino
Quinones, benzyl disulfide, tetramethylthiuram monosulfide
And the like. The photopolymerization sensitizer is based on the resin solid content.
A range of 0.1 to 10% by weight is desirable.   Then, a coating film containing such a photopolymerization sensitizer and a radiation-curable compound is irradiated with an ultraviolet ray.
Curing by wire may be performed according to various known methods.   For example, an ultraviolet light bulb such as a xenon discharge tube and a hydrogen discharge tube may be used.   On such an organic protective coat layer 6, a protective plate 7 is usually provided via an adhesive layer.
Be killed.   That is, from the back surface of the substrate 2 (the surface on which the magnetic thin film layer 5 is not provided) side
In the case of so-called single-sided recording in which recording / reproduction is performed only, this protective plate 7 is used.   The resin material of the protective plate 7 is not required to have a special transparency or the like. Various resins such as polyethylene, polyvinyl chloride, polystyrene, polypropylene
Ren, polyvinyl alcohol, methacrylic resin, polyamide, polyvinylidene chloride
Various thermoplastic resins such as thermoplastics, polycarbonates, polyacetals, fluororesins, etc.
Enol resin, urea resin, unsaturated polyester resin, polyurethane, alkyd
Various thermoplastic resins such as resin, melamine resin, epoxy resin, and silicon resin are used
It is possible.   Note that various inorganic materials such as glass and ceramic may be used as the protection plate 7.   The shape, dimensions, and the like of this are almost the same as those of the above-described substrate 2.   Such a protective plate 7 is bonded via the adhesive layer as described above. adhesive
The layer is usually an adhesive such as a hot melt resin and has a thickness of 1 to 100 μm.
Degree.   On the other hand, instead of using the protective plate 7, the magnetic thin film layer 5, the intermediate layer 4,
By further using one set of substrates having the layers 31 and 35, the organic protective coat layer 6, and the like,
Facing each other with the magnetic thin film layer inside and bonding using an adhesive layer,
A so-called double-sided recording type in which writing is performed from the front side may be used. In addition,
On the back surface of the substrate 2 and the protective plate 7 (the surface on which the magnetic thin film layer 5 is not provided), various
It is preferable to perform coating as a protective film. As coating material
May be the same as the material of the organic protective coat layer 6 described above.   V Specific effects of the invention   The optical recording medium of the present invention can record recording sensitivity, C / N ratio, and servo signals.
Good regenerating characteristics and corrosion resistance.   In addition, while maintaining such good characteristics, the film stress of the intermediate layer is reduced.
No warping occurs on the substrate. Also, even if the forming apparatus is used many times,
Furthermore, the disadvantage that a pinhole is formed in the intermediate layer is also eliminated.   VI Specific Examples of the Invention   Hereinafter, the present invention will be described in more detail with reference to examples of the present invention.   [Example 1]   13cm diameter, 1.2mm thick bisphenol A optical disc grade po A glass (SiO 2) is formed on a substrate 2 made of a carbonate resin._Two 48wt%, Al_TwoO_Three
 15wt%, B_TwoO_Three 14wt%, Ba_TwoO3wt%, K_TwoO_Two wt%, BaO5wt%, C
aO9 wt%, MgO4 wt%) protective layer 31 is applied by high frequency magnetron sputtering.
The layer was formed to a thickness of 0 nm.   On top of that, an intermediate layer 4 having various compositions shown in Table 1 below was formed by a sputtering method.
By multi-source sputtering. The film composition was determined by Auger spectroscopy.
It was measured. In addition, the film thickness of each sample is the enhancement of λ / 4n.
The optimum thickness (80 to 150 nm in this case) was set. R in Table 1 is yttrium
And one or more of lanthanoid elements.   On such an intermediate layer, 25 at% Tb, 63 at% Fe, 7 at% Co, 5 at% T
An i-alloy thin film is formed to a thickness of 800 ° by sputtering, and a magnetic thin film layer 5
did.   The target is an Fe target on which Tb, Co, and Ti chips are mounted.
Was used.   On this magnetic thin film layer 5, a protective layer 35 having the same composition as the protective layer 31 is further protected.
The layer was provided in the same manner as the layer 31.   On this protective layer 35, a coating composition containing the following radiation-curable compound is organically protected.
The protective coat layer 6 was formed by spin coating. (Coating composition)   Multifunctional oligoester acrylate                             100 parts by weight   5 parts by weight of photosensitizer   After applying such a coating composition, ultraviolet rays are irradiated for 15 seconds to cure by crosslinking,
It was made into a film.   Thus, various optical recording media as shown in Table 1 below were manufactured.   The sample No. Reference numeral 12 denotes a magnetic thin film layer 5 of 15 at% Tb, 10 at% Dy,
63at% Fe, 7at% CO, 5at% Ti alloy thin film.   Sample No. Reference numeral 13 denotes a magnetic thin film layer 5 of 17.5 at% Tb, 7.5 at% Nd,
63at% Fe, 7at% CO, 5at% Ti alloy thin film.   For these, the following characteristics were measured.   (1) C / N ratio   The C / N ratio was measured under the following conditions.   Linear velocity 4m / sec   Carrier frequency 1.0MHz   Resolution 30KHz   Video bandwidth 100Hz   Recording power (830nm) 3-6mW   Reproduction power (830nm) 1mW   (2) Reflectance   The reflectance at a wavelength of 830 nm on the flat portion was measured with a spectrophotometer.   (3) Corrosion resistance   Heat cycle test: IEC-2-38 (-10 ° C to 60 ° C, 90% RH)
)   The time when the burst error doubled in the above acceleration test was measured. In this condition
Mainly, peeling, cracks, etc. of the film contributed to the increase of the burst error.   Table 1 shows the results.   Sample No. Samples 12 and 13 are superior in recording sensitivity to other samples.
Was.   Those not containing one or more of yttrium and lanthanoid elements are:
The recording sensitivity was inferior to the other samples.   In addition, in addition to R shown in Table 1, at least one of Pr, Sm, and Eu was used.
In this case, the above-mentioned effect is similarly realized, and the phase transition type Te-Ge, TeO_x, Te
The same was realized with a recording layer such as -Se.   The effects of the present invention are clear from the above results.

[Brief description of the drawings]   FIG. 1 is a sectional view of a magneto-optical recording medium showing an example of the present invention.   Explanation of reference numerals   1: magneto-optical recording medium,   2 ... substrate   31, 35 ... protective layer,   4 ... Intermediate layer,   5 ... magnetic thin film layer,   6 ... Organic protective coat layer   7 ... Protective plate

Claims (1)

Claims: (1) In an optical recording medium having a recording layer on a substrate and an intermediate layer between the recording layer and the substrate, the intermediate layer comprises silicon, aluminum, oxygen and nitrogen. And Y and lanthanoid elements (La, Ce, Pr, Nd, Sm and E
u), the content of at least one of the yttrium and lanthanoid elements in the intermediate layer is 0.1 at% or more and less than 2 at%, and the total content of silicon and nitrogen is An optical recording medium having a content of 20 to 65 at%. (2) An optical recording medium having a recording layer on a substrate, an intermediate layer between the recording layer and the substrate, and a protective layer between the substrate and the intermediate layer and / or on the recording layer. The intermediate layer contains silicon, aluminum, oxygen and nitrogen, and further contains yttrium and lanthanoid elements (La, Ce, Pr, Nd, Sm and Eu)
And the content of at least one of yttrium and the lanthanoid element in the intermediate layer is at least 0.1 at% and less than 2 at%, and the total content of silicon and nitrogen is 20 to An optical recording medium having a content of 65 at%.