JP2002298436A - Optical information recording medium and method of manufacturing for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute an optical information recording medium which is excellent in the repetitive performance of a phase transition optical disk without increasing the total layers of layers. SOLUTION: A protective layer essentially consisting of Te-O is applied to at least either of the sides of the recording layer. As a result, the optical information recording medium which is excellent in the adhesiveness to the recording layer, can prevent the composition fluctuation of the recording layer and is excellent in both of the stability and the repetitive performance is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an optical information recording medium having an optically detectable recording layer and a method for manufacturing the same.

[0002]

2. Description of the Related Art A recording material thin film layer composed of a metal thin film or an organic thin film is formed on a disk-shaped or card-shaped substrate and irradiated with a high-energy beam focused on a minute light spot having a submicron-order diameter. A technique of causing a local change in the recording material layer by performing the above-described operation to thereby accumulate information signals is already widely known. Particularly, a medium using a magneto-optical material thin film or a phase-change material thin film for a recording layer has been actively researched and developed because a signal can be easily rewritten.

A medium usually has a multilayer structure as shown in FIG. 1, for example. That is, on a substrate 1 such as a polycarbonate or PMMA (polymethyl methacrylate) resin plate or a glass plate, a light absorbing material made of a phase change material or a magneto-optical material sandwiched between protective layers 2 and 4 made of a dielectric material. A method such as sputtering or vacuum vapor deposition of the metallic reflective layer 5 made of Au or an Al alloy, which functions to improve the light absorption efficiency of the recording layer 3 and the recording layer 3 or functions as a heat diffusion layer. And the overcoat layer 6 is formed. However, the laser beam is incident from the substrate 1 side.

When a phase change material is used for the recording layer 3, a chalcogenide thin film based on Te or Sb, for example, Ge-Sb-Te alloy thin film, Ge is added based on a eutectic composition of Sb-Te. System, Ge-Sn-Sb
-Te alloy thin film, In-Sb-Te alloy thin film, Ag
-In-Sb-Te alloy thin films and the like are often used. In a medium using such a phase change material, the recording layer is locally heated by irradiation with a laser beam, and a portion irradiated with relatively strong power is melted and then becomes amorphous in a quenching process.
In addition, rewrite recording is performed to reversibly generate a change that a portion irradiated with relatively weak power is crystallized in an annealing process.

The functions of the protective layers 2 and 4 made of a dielectric material include, for example, 1) a function of protecting the recording layer from mechanical damage from the outside, and 2) a function of the surface of the substrate caused by repetitive rewriting of signals. Function to reduce thermal damage such as roughness and breakage of recording layer and evaporation and to increase the number of repetitions. 3) Function to enhance optical change using interference effect by multiple reflection. 4) Function to cut off influence from outside air and to reduce chemistry. For example, Al ₂ O ₃ , TiO ₂ , SiO _2, etc., oxides such as Si ₃ N ₄ , AlN, etc. Nitrides, oxynitrides such as Si-ON (for example, JP-A-3-104038),
As a sulfide such as ZnS, a carbide such as SiC, or a mixture thereof, ZnS-SiO ₂ (Japanese Unexamined Patent Publication No.
53 No.) material such as have been proposed, but the protective layer material that is actually applied to a phase change optical disk that is commercialized is exclusively ZnS-SiO _2.

The reason that ZnS-SiO ₂ has been used is that it belongs to a class of dielectric materials having considerably low thermal conductivity, and the thermal diffusion generated when recording is performed by a laser beam or the like can be suppressed to a minimum. Sensitivity is increased, cracks are less likely to occur even when a thick film is formed due to small internal stress, adhesion to the phase change material layer is high, and peeling is difficult even after repeated laser irradiation. The present invention TeO based material is about to disclose or TeO _X system (1.2 ≦ x
≦ 2) There is no example that discloses a material or a Te-MO material to which an additive is added to be applied to the protective layer.

[0007]

However, as disclosed by the present inventors (N. Yamada et al., Jpn. J. Appl.
hys. Vol. 37 (1998) pp. 2104-2110), ZnS-SiO ₂
There are also issues with the protective layer. That is, when laser irradiation is repeatedly performed, S atoms having a relatively weak bond contained in the ZnS-SiO ₂ protective layer are released and diffused into the recording layer to change the optical characteristics and phase change speed of the recording layer. That is to let it. As a result, there has been a problem that the recording performance gradually deteriorates and the number of repetitions is limited. The authors, the diffusion of S atoms to form a nitride surface layer represented by Ge-N between the recording layer and the ZnS-SiO ₂ protective layers based on Te to overcome the above problems A method of suppressing is proposed. Indeed, it has been confirmed that according to this method, the diffusion of S is suppressed and the rewriting performance is improved repeatedly. However, the use of the interface layer causes an increase in the total number of layers, and as a result, a new problem arises from another viewpoint that manufacturing costs tend to increase.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an optical information recording medium having excellent repetition performance of a phase change optical disk without increasing the total number of layers.

[0009]

The present invention solves the above problems.
One of the information recording layers, preferably both
TeO in contact with the side surface_XOr containing Te-O as a main component
A protective layer is provided. The authors say that Te-O material is Te or
High adhesion to Sb-based information recording layer
I found it. Moreover, Te-O is chemically stable,
ZnS-SiO _TwoAnd diffused into the recording film
No S atoms are released. In addition, control of the composition
It is easy and can achieve an appropriate optical constant depending on the medium.
The melting point and refractive index are controlled by the additives.
It is also possible to control. At this time, the average of the Te-O thin film
Composition is TeO_X(1.2 ≦ x ≦ 2) is preferred
Ku, TeO_X(1.5 ≦ x ≦ 2.0)
Preferred.

The properties can be improved in various directions by the additive element M.
Group element (Ar, Kr, Xe), group Ib element (Cu, A
g, Au), Group IIa elements (Mg, Ca, Sr, Ba),
Group IIb element (Zn, Cd), Group IIIa element (Sc,
Y), Group IIIb elements (B, Al, Ga, In), Group IVa elements (Ti, Zr, Hf), Group IVb elements (C, Si, G
e, Sn, Pb), Va group elements (V, Nb, Ta), V
Group b element (N, Sb, Bi), Group VIa element (Cr, M
o, W), Group VIIa element (Mn), Group VIII element (Fe,
Co, Ni, Ru, Rh, Pd, Os, Ir, Pt),
Lanthanoid element (La), rare earth element (Dy, Eu,
Gd, Tb). Further, as one of the constituent elements, there is also possible to further include N, a composition of the protective layer Te _a M _b O
_c N _d (a + b + c + d = 100), [a ≧ b and c ≧ 5
0 at% and d = 0] or [a ≧ b and c + d ≧ 50
at% and c ≧ d> 0].

In this case, the information recording layer is preferably made of a phase change type material layer, and a first protective layer containing Te—O as a main component, an information recording layer, and a second Te—O layer are formed on a substrate. It is more preferable to laminate three layers including a protective layer whose main component is a three-layer or a multilayer film including four layers obtained by further adding a metallic reflective layer (or a heat dissipation layer) to the three layers. .

As a method for manufacturing a protective layer containing Te—O as a main component constituting an optical information recording medium, a deposition method from a gas phase is used. Especially preferably a sputtering method, as a sputtering target, TeO _X (0 formed by solidifying a Te target or Te and TeO ₂ powder mixture
≦ x ≦ 2) Use a target. At this time, when a Te target is used, a reactive sputtering method using a mixed gas of an inert gas and an oxygen gas or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas is used, and a TeO _x (0 <x
≦ 2) When a target is used, a normal sputtering method using an inert gas according to the composition, a mixed gas of an inert gas and an oxygen gas, or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas is used. By any of the reactive sputtering methods.

At this time, a sputtering method is also used as a method for adding the additive M to the Te—O film. As a sputtering target, Te-M alloy or Te-M mixed powder target or Te and TeO ₂ and M and M oxides (or M nitride or M oxynitride,) Te-M mixed powder was solidified by formation of -O- (N) target is used. At this time, when a Te-M alloy or a Te-M mixed powder target is used, a reactive sputtering method using a mixed gas of an inert gas and an oxygen gas or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas is used. , And Te-MO-
(N) When a target is used, a normal sputtering method using an inert gas depending on the composition, a mixed gas of an inert gas and an oxygen gas, or a mixed gas of an inert gas, an oxygen gas, and a nitrogen gas is used. By any of the reactive sputtering methods.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION One of the optical information recording media of the present invention.
An embodiment is shown in FIG. In this embodiment, the substrate 1
Is a disk-shaped polycarbonate resin substrate having a thickness of 0.6 mm and a diameter of 120 mm. As the material used for the substrate, polycarbonate is generally excellent in that it has low hygroscopicity and low cost, but in addition, glass, acrylic resin, polyolefin resin, vinyl chloride, etc. can also be used. . A metal is also used, but in this case, the recording light beam cannot enter through the substrate. Therefore, it is necessary to design the structure of the medium so that the light enters from the side where the film is formed. In any case, the type of substrate does not limit the present invention.

The surface of the substrate is optically sufficiently smooth, and a spiral groove track 7 having a depth of, for example, 60 nm and a groove width of 0.615 is formed on the surface on which the multilayer film is formed.
.mu.m and a land width of 0.615 .mu.m are formed on almost the entire surface, and the laser beam for recording and reproducing the information signal can be moved to an arbitrary position on the disk by using the concave and convex shape of the groove as a guide. As a laser beam guiding method, there are known a continuous servo method using the spiral groove or the groove formed concentrically, and a sample servo method for tracking a periodically arranged signal pit row. A groove or the like is appropriately formed in the substrate 1 according to the beam guiding method, but this is not related to the essence of the present invention.

On the surface of the substrate 1 on which the groove tracks 7 are formed,
Is, in order, Te₃₀Zn_TenO₆₀Protective layer (130 nm), Ge
_TwoSb_TwoTe_FiveRecording layer (10 nm), Te₃₀Zn_TenO₆₀Security
Protective layer (30 nm), Al reflective layer (100 nm)
Are formed in this order by a sputtering method, and are cured by ultraviolet rays.
The same resin plate as the substrate 1 is used for the protection plate 1
It is stuck as 0. Conventionally, as a protective layer material
Only ZnS-SiO _TwoHas been used. For this reason
Is i) ZnS-SiO_TwoIs quite hot in dielectric
It belongs to the class of low conductivity and is recorded by laser beam etc.
Recording can be suppressed to a minimum.
Recording sensitivity is increased, ii) cracks even when a thick film is formed due to low internal stress
Iii) has high adhesion to the phase change material layer,
As mentioned above, there are some things that are difficult to peel off even if repeated.
Iii) that there were few materials with excellent performance
This point was decisive. However, that
According to a later study by the authors, when laser irradiation is repeated,
ZnS-SiO_TwoAtoms are released from the layer and into the information recording layer
And that gives rise to strong adhesion
It is thought that there was. In other words, conventional materials have improved adhesiveness.
In exchange, performance was repeatedly reduced.

On the other hand, the reason why the Te—O material exhibits excellent adhesiveness to the information recording layer has not been clarified yet, but it is a phenomenon that large atom diffusion occurs between the Te—O material and the recording layer. Has not been observed. Further, in the Te-O system, even if Te diffuses into the recording layer, Te is often the main component of the recording layer, and there is an advantage that the possibility of causing a problem is small. The Te—O thin film is usually formed in an amorphous state, and at this time, there is a great feature that the refractive index and the absorption coefficient can be continuously and easily controlled by the average composition. That is, since the refractive index and the absorption coefficient increase continuously as the Te component increases, the composition can be optimized as necessary.

For example, when the structural flexibility is desired to be increased, the melting point is required to be lowered, or the absorption is desired to be slightly increased, the Te concentration is increased. Conversely, if a slightly harder film is desired, if the melting point is to be increased, or if the film is to be made completely transparent, the O concentration should be increased. In the Te-O system, crystallization is likely to occur when the Te concentration is higher than a certain concentration, and it may be used as a recording material (Takenaga et al. J. Appl.
hys. Vol. 54 (9), pp. 5376-5380, 1983), where the O concentration is set sufficiently high so that crystallization does not occur. That is, in order to use a Te—O film as a protective layer, the average composition in the thickness direction is selected to be TeO _x (1.2 ≦ x ≦ 2.0). In order to obtain a more transparent film, TeO _x (1.5 ≦
x ≦ 2.0) is preferable.

An additional element M can be added to the Te—O film. As a result, various characteristics can be improved. Generally, when the additive concentration exceeds the Te atom concentration, the excellent performance of Te—O is undesirably reduced. Also, usually, a Te concentration of 1
At / 10 or more, the effect becomes remarkable.

As the additive element M, there are various elements as described below. First, Ar, Kr, Xe, and the like are rare gases that hardly form a compound. The rare gas is inevitably included in the film when a thin film is formed by a sputtering method using the gas as a sputtering gas. However, the rare gas usually contributes in the direction of reducing the optical constant (refractive index, extinction coefficient). . In this case, the oxygen concentration giving preferable characteristics is the same as in the case where there is no additive.

Next, as an element which is less likely to form an oxide than Te, there is an element which has a smaller standard energy of oxide formation than Te and has a smaller tendency to oxidize than Te. For example,
Noble metal elements such as Ag, Cu, Au, Pd, and Pt.
These elements are likely to exist as non-oxides in the film, and usually contribute to increasing the optical constants (refractive index, extinction coefficient). In this case, since Te is preferentially oxidized in the film, the oxygen concentration that gives preferable characteristics is approximately the same as in the case of no additive or rare gas.
In this case, it is preferable that the entire oxygen concentration does not fall below 50%.

A desirable composition is a protective layer material composition Te-M
The composition point A (33.3, 0, 66.7) showing TeO ₂ , the composition point C (45.5, 0, 54.5) showing TeO _1.2 and the composition point M are shown in the triangular composition diagram of FIG. A composition point F (25, 25, 25) that a straight line cA connecting the points c and A intersects a straight line id connecting the composition point j indicating the TeO and the point d indicating the composition point MO.
50), a composition range ACD-D- surrounded by four composition points D (41.5, 8.5, 50) where a straight line cC connecting the points c and C indicating the composition point M intersects the straight line jd. It is desirable to be within F.

Here, when the composition has an O concentration lower than the composition line jd, the light absorption increases and the optical loss as the protective layer increases. In this sense, the composition point c and TeO
_A straight line cB connecting the composition point B (40, 0, 60) indicating _1.5
Defines a composition point E (33, 17, 50) that intersects with the straight line jd, and a transparent film can be obtained when the composition point is within the four composition points ABEF. preferable. If the composition is Te-rich than the composition cC, the thermal stability decreases.

In the region rich in O than the composition line cA, unbonded O atoms are present in the film, so that the recording layer is oxidized, which is not preferable. Also, the additive effect becomes remarkable when the additive concentration is 1/9 or more of Te (Te-
10% or more in M), a composition line ai and a composition line c connecting a composition point a indicating Te ₉₀ O ₁₀ and a composition point i indicating O.
Intersection with A and composition line cC, A1 (32.5, 3.5, 65)
By defining C1 (43, 5, 48), the composition region A1
-C1-DF is represented.

Next, there are elements whose standard energy of formation of oxide is smaller than that of Te and whose oxidation tendency is larger than that of Te.
Since Te belongs to an element that is relatively difficult to oxidize, these types of elements are very numerous. These are oxides of T
It can form a mixture or complex oxide with e-O to modify the properties of Te-O. For example, the melting point of TeO ₂ is 7
Although it is 33 ° C., the melting point of the entire system can be increased by adding an element forming an oxide having a higher melting point.

For example, Al, Bi, Cr, Dy, Eu,
Fe, Gd, Ge, Hf, Ho, In, La, Mg, M
n, Mo, Nb, Ni, Pb, Sc, Si, Sr, T
a, Tb, Ti, V, Y, Zn, and Zr are promising. Thereby, heat resistance as a protective layer can be increased. In particular, Al, Dy, Gd, Mg, Nb, Sc,
Si, Sr, Ta, Tb, Ti, Y, Zn, and Zr are suitable as additives because they form highly transparent oxides. If the melting point is too high, the internal stress is not easily relaxed and cracks are easily formed, so that the additive concentration needs to be appropriately selected. In general, exceeding the concentration of Te atoms is not preferable because excellent performance of Te-O is reduced. Further, the effect is usually remarkable from about 1/9 or more of the Te concentration.

Conversely, if an element forming an oxide having a low melting point is added, the melting point of the entire system can be lowered. For example, Sb is dominant. Generally speaking, it is desirable that the melting point of the protective layer be higher than the melting point of the recording material layer, but there are cases where there is a merit that by approaching the melting point of the recording material layer, it is easy to follow the deformation of the recording layer that occurs during recording. is there. Generally, the melting point of a phase change recording material based on Te or Sb is about 500 ° C. to 700 ° C., so that it is preferable to lower the melting point of the Te—O system to 733 ° C. of TeO 2 in accordance with the material system. There is also. Also in this case, it is desirable that the concentration of the additive does not exceed the concentration of Te atoms.

A desirable composition as a whole is that the additive element is
It depends on the form of the stoichiometric oxide that is inherently formed.
For example, if the oxide produced is MO,
The preferred composition is the triangular composition diagram shown in FIG.
dA and dC have the composition Te ₅₀M₅₀And a composition point b indicating
Intersect with the composition line bi connecting the composition points i indicating the formation O
Points, G (24,24,52) and I (20,20,60)
However, it is preferable to be within the composition region ACGI.
The composition point H (22,22,22) where the composition line ai and the composition line dB intersect
56), and within the four composition points ABHI,
Since a more transparent film can be obtained, it is preferable in terms of optical design.

On the right side of the composition line dC, the optical transmittance decreases, which is not preferable in optical design. Below the composition line bi, the adhesion performance, which is a characteristic of the Te—O film, is undesirably reduced. On the left side of the composition line dA, unbound O
Since the atoms are present, the recording layer is oxidized, which is not preferable. Further, the composition lines ai and dA and d
Intersection A2 (31,3.5,65.5) with B, C2 (41.5,4.
5, 54), the effect of the additive M becomes more remarkable in the composition range A2-C2-GI. As M for generating MO, Zn, Mg, Sr, and Nb showed good performance.

Hereinafter, as in the case of FIG. 4, FIGS.
7, in each of FIGS. 8, the form of oxides resulting additive M showed a proper range of the protective layer composition in a _{M 2 O 3, MO 2,} M 2 O 5, MO 3 . That is, when M generates M ₂ O ₃ , A (33.3,0,66.7),
C (45.5, 0, 54.5), J (21.5, 21.5, 57), L (1
8, 18, 64)
A (33.3, 0, 66.7), B (40, 0, 60), K (20, 2
0, 60) and L (18, 18, 64). A3 (30.5, 3.5, 66), C
3 (40.5, 4.5, 55), J (21.5, 21.5, 57), L (1
8, 18, 64), the effect of the additive is remarkable in the composition region. M is Al, Bi, Cr, Dy, Eu, G
d, Ho, La, Sb, Tb, Ti, and Y showed preferable performance.

When M generates MO ₂ , A (33.3, 0, 66.7), C (45.5, 0, 54.5),
It is preferably in a composition range surrounded by M (24, 24, 52) and O (16.7, 16.7, 66.6), and A (33.3, 0, 66.7),
B (40, 0, 60), N (23, 23, 54), O (16.7, 16.
More preferably, it is in the composition range enclosed by 7, 66.6). A4 (30, 3.3, 66.7), C4 (39.5, 4.5,
56), M (24, 24, 52), O (16.7, 16.7, 66.6) surrounded by a composition region where the additive effect is remarkable. S for M
i, Ge, Mn, Sn, Ti, Zr showed preferable performance.

When M generates M ₂ O ₅ , in FIG. 7, A (33.3,0,66.7), C (45.5,0,54.5),
It is preferably in a composition range surrounded by P (17.5, 17.5, 65) and R (15.5, 15.5, 69), and A (33.3, 0, 66.
7), B (40, 0, 60), Q (16.5, 16.5, 67), R (1
More preferably, it is in the composition range enclosed by 5.5, 15.5, and 69). A5 (29.5, 3.5, 67), C5 (38.5,
4.5, 57), P (17.5, 17.5, 65), R (15.5, 15.5, 6
In the composition region surrounded by 9), the additive effect is remarkable. As M, Nb, Sb and Ta showed preferable performance.

When M generates MO ₃ , A (33.3, 0, 66.7), C (45.5, 0, 54.5),
It is preferably in a composition range surrounded by S (16.5, 16.5, 67) and U (14.5, 14.5, 71), and A (33.3, 0, 66.
7), B (40, 0, 60), T (15.5, 15.5, 69), U (1
4.5, 14.5, 71). A6 (29, 3, 68) and C6 (38, 4, 5)
8), the composition region surrounded by S (16.5, 16.5, 67) and U (14.5, 14.5, 71) has a remarkable additive effect. As M, Sc showed preferable performance.

When the element to be added easily forms a nitride, it is also effective to partially nitride it and to include it as a nitride oxide in the film. For example, Al, Si, Ti, Nb, Z
Elements such as r and Ta. In general, nitrides have characteristics such as a higher melting point than oxides, low structural flexibility, and high light absorptivity. When the nitrides are too large, cracks are likely to occur or optical efficiency is reduced. Te of the present invention
In the protective layer based on -O, it is desirable that the nitrogen concentration does not exceed the oxygen concentration. Composition formula of the material system, and may include a nitrogen, separately if not _{included, Te a M b O c N} d (a +
b + c + d = 100) [a ≧ b and c ≧ 50 at% and d = 0] or [a ≧ b and c + d ≧ 50 at% and c
≧ d> 0]. The following is a summary of the additive elements by group.

Group 0 elements (Ar, Kr, Xe), Group Ib elements (Cu, Ag, Au), Group IIa elements (Mg, Ca, S
r, Ba), IIb group element (Zn, Cd), IIIa group element (Sc, Y), IIIb group element (B, Al, Ga, I
n), group IVa elements (Ti, Zr, Hf), group IVb elements (C, Si, Ge, Sn, Pb), group Va elements (V, N
b, Ta), group Vb elements (N, Sb, Bi), group VIa elements (Cr, Mo, W), group VIIa elements (Mn), group VIII elements (Fe, Co, Ni, Ru, Rh, Pd, Os , I
(r, Pt) lanthanoid element (La) rare earth element (D
y, Eu, Gd, Tb).

The material forming the recording layer 3 is a phase change material which undergoes a reversible state change upon irradiation with an energy beam such as a laser beam, and in particular, reversible between an amorphous state and a crystal upon irradiation with a laser beam. Those that produce a phase change are preferred. Typically, instead of Ge ₂ Sb ₂ Te ₅ ,
-Sb-Te, Ge-Sn-Sb-Te, Ge-Te,
In-Sb-Te, Sb-Te, Ge-Sb-Te-P
d, Ag-Sb-In-Te, Ge-Bi-Sb-T
e, Ge-Bi-Te, Ge-Sn-Te, Ge-Sb
-Te-Se, Ge-Bi-Te-Se, Ge-Te-
Sn-Au, Ge-Sb-Te-Cr, In-Se, I
n-Se-Co, Ge-In-Sb-Te, Ge-A
A system containing g-In-Sb-Te or the like as a main component, or various material systems obtained by adding an additive such as oxygen or nitrogen to these systems can be used.

These thin films are usually in an amorphous state when formed, but can be crystallized by laser irradiation or can be made amorphous again, and the change in the optical characteristics that occurs at that time can be reduced. It can be used to record and reproduce information. The recording film can be made amorphous by irradiating the recording film with short pulse light and melting and quenching the local portion. In addition, it can be annealed and crystallized by heating at a temperature equal to or longer than the crystallization temperature and equal to or longer than the case of the amorphization.

The reflection layer 5 is composed of a multilayer film combining a metal material layer or a dielectric film. In addition to Al, A
u, Ag, Pd, Ni, Cr, Ta, Ti, Si, etc. can be used alone or as an alloy based on them. For example, Au-Cr, Au-Co, Al-Ta,
Al-Ti, Al-Cr, Ag-Pd-Cu, Ag-C
Alloys such as r, Ni-Cr and Au-Pd are preferred. The reflective layer is not essential, but is preferably used to increase the heat dissipation efficiency and the degree of freedom in optical design.

FIG. 2 shows a configuration in which the overcoat layer 6 is provided on the uppermost layer. The overcoat layer 6 protects the protective layer and the recording layer of the optical information recording medium from the influence of moisture, dust and the like. For example, as shown in FIG. 9, a configuration in which a dummy substrate (cover plate, cover layer) 9 is bonded via an adhesive layer 8, using an adhesive with the overcoat layer surface inside. It is appropriately used according to a conventional method, such as a configuration in which two sheets are bonded together. For bonding, an adhesive such as a hot melt adhesive or an ultraviolet curable resin is applied.

As a medium configuration, as shown in FIG.
A multilayer film is formed on the substrate in the reverse order of the conventional one, and a cover layer 1 having a thickness of about 0.1 mm thinner than the conventional one is formed thereon.
There is also a method in which laser irradiation is performed from the side of the cover layer, but a material layer containing Te-O as a main component of the present invention can be similarly applied. For the cover layer, either a method of attaching a sheet or a method of spin-coating a resin layer can be used.

Next, a method of manufacturing the optical information recording medium will be described. The multilayer film constituting the recording medium of the present invention can be formed by a vapor deposition method such as vacuum evaporation, sputtering, laser sputtering, ion plating, and CVD. Then it is difficult for dust to come out,
It is preferable to use the sputtering method because the temperature of the substrate does not easily rise. Te of the optical information recording medium of the present invention
Layers other than the -O layer can be formed by a conventional method. In the case of the Te-O-based material of the present invention, there are a case where an oxide target is used and a case where an alloy target is used depending on the additive. For example, it is possible to perform sputtering using an inert gas such as Ar or Xe using a Te—O target. In this case, O and N are mixed at an appropriate concentration in the inert gas to perform sputtering. By doing Te
The degree of oxidation and the degree of nitridation can be controlled.

The composition of the target can be changed by the additives. For example, since it is difficult to handle a group IIa element as a simple substance, it is preferable to treat it as an oxide. For example, a mixture target of Mg-O and Te-O or a mixture target of Mg-O and Te is used. When an element that is easily oxidized is added, it is more convenient to treat it as an oxide. For example, Tb, Gd, D
rare earth elements such as y and Eu, lanthanoid elements such as La,
Group IIIa elements such as Sc and Y, and I such as Ti, Zr and Hf
Va group element, Va group element such as V, Nb, Ta, etc., Cr, M
Group VIa elements such as o and W and group VIIa elements such as Mn are more convenient to be treated as oxides because of their high melting points in addition to their easy melting points. However, these can be treated as a single unit. Here, sputtering is performed using an inert gas such as Ar or Xe. At this time, the sputtering is performed by mixing N or O into the inert gas and performing sputtering.
And the degree of oxidation and the degree of nitridation of Mg as an additive can be controlled.

In the case of the same Group II element of the Group IIb element, Zn
An alloy with Te, such as Te or CdTe, can be easily formed. For example, when adding Zn, the mixing ratio of Te and Zn is optimized according to the required Zn concentration,
For example, sputtering can be performed from an alloy target such as Te ₈₀ Zn ₂₀ or Te ₇₀ Zn ₃₀ . As a sputtering gas, a mixed oxide film of a Te oxide and a Zn oxide can be obtained by mixing O into an inert gas such as Ar or Xe and performing reactive sputtering. At this time, by changing the gas pressure, the partial pressure ratio, and the sputtering speed as sputtering conditions,
Oxygen concentration can be controlled. Further, by further mixing and sputtering N, a nitride oxide can be formed. In the present embodiment, a Te ₇₅ Zn ₂₅ target is used, and Ar gas 35% and O ₂ gas 65
% Of a mixed gas, and was formed by a DC sputtering method of 100 W at a degree of vacuum of 0.4 Pa.

A metal element having a relatively low melting point or an element having a low oxidation tendency, for example, a group IIIb element (B, Al, Ga, I
n), group IVb elements (Si, Ge, Sn, Pb), and group Vb elements (Sb, Bi) are easier to alloy as in the case of Zn and Te, but as a single element in Te-O. It can be mixed, or a target can be made by mixing with Te or Te-O as the oxide MO. However,
C employs a method in which the C is included as a hydrocarbon in the sputtering gas or mixed as a carbide of another element, for example, SiC or WC. As a clue to know whether or not Te is easily oxidized, there is Gibbs' standard free energy of formation that generates oxides. As the energy is higher, an oxide is more easily formed. Therefore, compared to the free energy for forming a Te oxide (-270.3 KJ / mol), it can be said that an oxide having a higher absolute value is easier to generate an oxide than Te.
The Chemical Handbook revised by the Chemical Society of Japan, III Edition, Basic Edition II (P3
05-).

Since noble metal elements such as Au, Pt, Pd, and Rh are not easily formed into oxides, they are alloyed with Te or mixed as a simple substance in Te-O. Further, any of Group VIII elements (Fe, Co, Ni) and the like are possible.

The recording medium that had been bonded was subjected to an operation (initialization) of crystallizing the recording layer in advance. The initialization was performed by laser irradiation as described below. A disk medium is rotated at a constant linear speed of 5 m / s at a wavelength of 780 n.
m laser beam at 1 μm × 100 μm on the disk surface
(Half width) It was shaped so as to form an elliptical spot, and its long direction was arranged in the radial direction, and crystallization was performed sequentially from the outer periphery to the inner periphery of the disk at a pitch of 30 μm / rotation. .

The method for manufacturing the optical information recording medium according to one embodiment of the present invention has been described above. The above-described method is essentially the same even when the number of layers of the multilayer film to be formed and the thickness of each layer change. Next, a method for recording and reproducing a signal on the optical information recording medium formed as described above will be described.

As shown in FIG. 11, for evaluation of recording characteristics, an optical head 13 on which a semiconductor laser light source 11 having a wavelength of 660 nm and an objective lens 12 having a numerical aperture of 0.6 were mounted.
A linear motor 14 as a transporting means for guiding the optical head to an arbitrary position on the recording medium, a tracking servo mechanism and a circuit (not shown) for controlling the position, and controlling the attitude of the optical head to form a laser spot on the recording film. A focusing servo mechanism and circuit for irradiating the surface (not shown), a laser drive circuit for modulating the laser power, and a time interval analyzer (not shown) for measuring the jitter value of the reproduced signal. Although a deck provided with a motor 15 is used as a rotation control mechanism for rotating an optical disk, the present invention can be applied even when the laser wavelength is further reduced to 400 nm or less. It is obvious from the principle that it does not depend on NA.

When recording or overwriting a signal, first, the disk 16 is rotated at a predetermined rotation speed, the linear motor is operated to move the optical head to an arbitrary track position, and then the focus servo mechanism is operated to record the laser beam 17. The laser beam is focused on the film surface, and then the tracking servo mechanism is operated to cause the laser beam to track an arbitrary track. Next, the laser drive circuit is activated to change the laser output according to the information signal as shown in FIG. By irradiating the optical information recording medium with power by performing power modulation between the crystallization pulse portion having the crystallization pulse portion and the crystallization pulse portion, a state in which an amorphous portion and a crystalline portion are alternately formed is formed.

It should be noted that the peak pulse portion may be formed as a so-called normal multi-pulse formed by a narrower pulse train. The portion irradiated by the amorphizing pulse portion is instantaneously melted and then rapidly cooled to be in an amorphous state, and the portion irradiated by the crystallization pulse portion is annealed to be in a crystalline state.

Next, at the time of reproducing a signal, the irradiation power of the laser beam is set to a reproduction power level lower than the power level used for crystallization that does not add a further change to the optical information recording medium. The portion where the optical change occurred was scanned, and the detector received and detected a change in intensity of reflected light or transmitted light depending on the difference between the amorphous state and the crystalline state. Note that the pulse waveform is not limited to that shown in FIG. 12. For example, as shown in FIG. 13, (A) the amorphizing pulse is switched between the amorphizing power level and the level equal to or lower than the reproducing power. Modulate, (B) make only the first pulse and the last pulse relatively longer than the middle part, (C) make the pulse width of amorphization uniform, or (D) irradiate without pulse modulation at the time of amorphization, (E) Various recording / reproducing / erasing methods can be applied, such as providing a period in which the reproducing power level is always equal to or lower than before and / or after the amorphizing pulse, and combining them.

Here, the evaluation was performed based on the DVD-RAM standard Ver.2.0. The signal system is 8-15 modulation, the shortest recording mark length is 0.42 μm, and the shortest bit length is 0.2.
8 μm. The disk is fixed on a turntable and rotated at a linear velocity of 8.2 m / s. Overwriting of a random signal for randomly recording a mark length in a groove track within a range of 3T to 11T is repeated, thereby changing the signal amplitude and jitter. values (percentage of the sum sigma _sum of the window width T _w of the standard deviation sigma of a jitter value of each signal mark 3T to 11T sigma
A _sum / T _w, examined the change of that) and may be equal to or less than 12.8%.

For comparison, in addition to the disk (A) having the structure of the embodiment, in (A), only the lower side of the Te-O-based protective layer was changed to the conventional ZnS-SiO ₂ (SiO ₂ : 20 mol%). Disk (B), only upper side of conventional ZnS-SiO
Disk (C) changed to ₂ (SiO ₂ : 20 mol%),
Conventional ZnS-SiO ₂ (SiO ₂ : 20
mol%), and a Te—O-based protective layer (Te ₃₅ O ₆₅ = TeO _1.85 ) that does not contain Zn on both upper and lower sides was prepared, and the repetitive performance was compared.

The first evaluation item is a jitter value after 100,000 repetitive recordings (a method of independently measuring a jitter between a mark front end and a front end and a jitter between a mark rear end and a rear end). ), When both the jitter between the mark front end and the front end and the jitter between the mark rear end and the rear end are below the reference value, and there is almost no change, ◎, the change but the value of the jitter itself is the reference The case where the value was less than the value was represented by ○, the case where the standard was slightly exceeded by 100,000 times was indicated by Δ, and the case where the standard was already exceeded by 10,000 times was indicated by ×. The evaluation power is set to be about 10% higher than the lower limit jitter value at which the initial jitter value satisfies 12.8% or less.

The second of the evaluation items is 1 in the upper test track.
The results of observing the amplitude after the repetition of 100,000 times are as follows: a case where there is almost no change is indicated by ◎; a case where a change of about 10% or less is observed is ○; a change of about 20% is indicated. What was seen was △, what was much lower than that was ×
And

The third evaluation item is weather resistance. Put the prototype disk in a high temperature and high humidity environment of 90 ° C and 80% RH.
After leaving for 00 hours and 400 hours, observation with a microscope was performed. ◎: No abnormality was observed even after 400 hours, ○: Slight peeling was observed after 200 hours, ○: Slight peeling was observed in 200 hours, Δ: Large peeling by 200 hours Was evaluated as x.

The above results are shown in (Table 1). Table 1 shows that the configuration of the present invention can provide excellent characteristics in both the repetition characteristics and the weather resistance. Z to TeO ₂
It was found that n addition was also effective.

[0058]

[Table 1]

Hereinafter, the present invention will be described in detail with reference to more specific examples.

(Specific Example 1) Te ₁₀₀ M _100-x (x = 2,
5,10,20,25,33,40,50,60,7
In the form of 0), M is Al, Nb, Si, Ta, Ti, Zn,
A Te-M alloy target made of Zr, Dy, and Sb was prepared, and a Te-MO film was formed by a sputtering method. It was confirmed by the ICP method that the Te-M element ratio in the film was approximately equal to the target composition. The sputtering conditions are Ar
Using a mixed gas of gas and O ₂ gas, each
Is a reactive sputtering method at a vacuum degree of 100 W. In each case, the concentration of O ₂ gas was changed to change the O concentration in the film.
The oxygen concentration in the obtained film was determined by SIMS using a standard sample.
(Secondary ion mass spectrometry). The film under each condition was evaluated in the same manner as in the above-described embodiment.
It was found that the effect of improving the repetition performance was effective when it was 〜50%. Less than 5% has little effect, 50%
If it exceeds, the weather resistance (adhesion performance with the recording layer) was reduced.
When the oxygen concentration in the film was less than 50%, the repetition performance was reduced.

(Specific Example 2) In Example 1, when a protective layer was formed by mixing N ₂ gas with O ₂ gas in half in addition to Ar and O ₂ as a sputtering gas, Al, Nb except Zn was removed. ,
It was found that the elements of Si, Ta, Ti, and Zr increased the number of repetitions, though slightly, by about 20%. The effect is obtained even when the N ₂ concentration is about 10% of the O ₂ concentration. Since each element also towards oxidation proceeds preferentially over nitride, N ₂ was able to put up quite a lot. It was preferable to select from a range of 10% to 10 times the O ₂ concentration. When the O ₂ concentration exceeds 10 times, the degree of nitridation of the film is excessively advanced, and as a result, there arises a problem that the adhesiveness to the recording layer is reduced.

(Example 3) In Example 2, the composition of the recording film was changed to G
e _2.5 Sn _1.5 SbTe ₇ and _{(Sb 0.70. Te 0. 3)} 95
The same effect as Ge ₅ was confirmed.

(Specific Example 4) Te-O-based and Te-Ti
The adhesiveness with the Ge ₆ Sb ₂ Te ₉ film was examined in the —O system. T
If when the oxygen concentration in the e-O-based approaches TeO ₂ increases, shows a slight decline adhesion performance of the recording layer, in practice showed excellent adhesion regardless of the composition. Also Te
A similar tendency if the -ti-O system, when the oxygen concentration is approaching the TeO ₂ -TiO ₂ with increased, tended to adhesion performance decreases slightly regardless of the Ti concentration. Ti is Te
Therefore, Ti is preferentially oxidized in the film. In a film having a high oxygen concentration, all Ti atoms are oxidized, but some of the Te atoms remain unbonded. Will be. That is, in each case, the result was obtained that it is desirable that a small amount of Te be left without being oxidized. However, if the remaining unbound Te is too much,
A tendency to increase the optical density was also confirmed.

(Example 5) In Example 4, the composition of the protective layer was changed to T.
e-Zn-O, Te-Mg-O, Te-Si-O, Te
-Zr-O, Te-Al-O, Te-Bi-O, Te-
Discs having various compositions were prepared as Nb-O, Te-Ta-O, and Te-Sc-O, and evaluations were made according to the embodiment and the specific example 1. As a result, Te—Zn—O, Te using an additive that forms a stoichiometric oxide called MO.
-Mg-O showed excellent repetition performance and adhesion performance in the region shown in FIG. For example, as shown in (Table 2), No. No. 1 to No. The Te-Zn-O samples up to 8 showed the results as shown in (Table 2).

[0065]

[Table 2]

Further, Te—Al—O, Te—Bi—O using an additive forming a stoichiometric oxide called M ₂ O _3.
Showed excellent repetition performance and adhesion performance in the region shown in FIG. For example, no. No. 1 to No. Up to 8 Te-Al-O protective layer samples showed results as shown in (Table 3).

[0067]

[Table 3]

Also, Te—Si—O, Te—Zr—O using an additive forming a stoichiometric oxide called MO _2.
Showed excellent repetition performance and adhesion performance in the region shown in FIG. For example, no. No. 1 to No. Up to 8 Te-Si-O protective layer samples showed results as shown in (Table 4).

[0069]

[Table 4]

Further, Te—Ta—O, Te—Nb—O using an additive forming a stoichiometric oxide called M ₂ O _5.
Showed excellent repetition performance and adhesion performance in the region shown in FIG. For example, no. No. 1 to No. Up to 8 Te-Nb-O protective layer samples showed results as shown in (Table 5).

[0071]

[Table 5]

Further, Te-Sc-O and Te-WO using MO ₃ , an additive for forming a stoichiometric oxide, have excellent repetition performance and adhesion performance in the region shown in FIG. Indicated. For example, no. No. 1 to No. T up to 8
The e-Nb-O protective layer sample showed the results as shown in (Table 6).

[0073]

[Table 6]

[0074]

According to the present invention, it is possible to realize an optical information recording medium in which fluctuations in recording characteristics and reproduction characteristics due to repetition of recording and reproduction are small and excellent in weather resistance.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a conventional phase change optical recording medium.

FIG. 2 is a cross-sectional view showing one configuration example of the optical information recording medium of the present invention.

FIG. 3 is a first triangular composition diagram showing the composition of a protective layer used in the optical information recording medium of the present invention.

FIG. 4 is a second triangular composition diagram showing the composition of a protective layer used in the optical information recording medium of the present invention.

FIG. 5 is a third triangular composition diagram showing the composition of a protective layer used in the optical information recording medium of the present invention.

FIG. 6 is a fourth triangular composition diagram showing the composition of the protective layer used in the optical information recording medium of the present invention.

FIG. 7 is a fifth triangular composition diagram showing the composition of a protective layer used in the optical information recording medium of the present invention.

FIG. 8 is a sixth triangular composition diagram showing the composition of the protective layer used in the optical information recording medium of the present invention.

FIG. 9 is a sectional view showing another configuration example of the optical information recording medium of the present invention.

FIG. 10 is a sectional view showing another example of the configuration of the optical information recording medium of the present invention.

FIG. 11 is a diagram of an evaluation system for recording / reproducing a signal to / from the optical information recording medium of the present invention.

FIG. 12 is a diagram of a laser waveform for recording / reproducing a signal to / from the optical information recording medium of the present invention.

FIG. 13 is a diagram of another laser waveform for recording / reproducing a signal to / from the optical information recording medium of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2, 4 Protective layer 3 Information recording layer 5 Reflective layer 6 Overcoat layer 7 Groove track 8 Adhesive layer 9 Dummy substrate (cover substrate) 10 Thin cover layer (thin cover plate) 11 Laser light source 12 Objective lens 13 Optical head 14 Transfer mechanism (linear motor) 15 Rotation control mechanism (motor) 16 Disk 17 Laser beam

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (reference) G11B 7/24 538 G11B 7/24 538B B41M 5/26 7/26 531 G11B 7/26 531 B41M 5/26 X (72 ) Inventor Takashi Nishihara 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. FA12 FA14 FA25 FB09 FB12 FB25 5D029 JA01 JC18 LA13 LA14 LA17 LB04 LB07 NA23 5D121 AA04 EE03 EE09 EE11 EE14 EE17

Claims (29)

[Claims] 1. A multi-layered film including an information recording layer and a protective layer is provided on a substrate.
An optical information recording medium for reproducing information, wherein an optical information recording medium provided with a protective layer containing Te-O as a main component on at least one surface in contact with the information recording layer. 2. The Te—O thin film having an average composition of TeO
_2. The optical information recording medium according to claim 1, wherein _X (1.2 ≦ x ≦ 2.0). 3. The average composition of a Te—O thin film is TeO.
3. The optical information recording medium according to claim 2, wherein _X (1.5 ≦ x ≦ 2.0). 4. The Te—O thin film further contains N, and its concentration does not exceed the O concentration.
The optical information recording medium according to any one of the above. 5. A thin film containing Te—O as a main component has a group 0 element (Ar, Kr, Xe) and a group Ib element (Cu, A) as an additive element M.
g, Au), Group IIa elements (Mg, Ca, Sr, Ba),
Group IIb element (Zn, Cd), Group IIIa element (Sc,
Y), Group IIIb elements (B, Al, Ga, In), Group IVa elements (Ti, Zr, Hf), Group IVb elements (C, Si, G
e, Sn, Pb), Va group elements (V, Nb, Ta), V
Group b element (N, Sb, Bi), VIa group element (Cr, M
o, W), Group VIIIa element (Mn) Group VIII element (Fe, C
o, Ni, Ru, Rh, Pd, Os, Ir, Pt) lanthanoid element (La) rare earth element (Dy, Eu, Gd,
Comprises at least one selected from among Tb), comprises the N is in accordance with the addition _{condition, Te a M b O c N} d (a + b + c + d = 100) [a ≧ b and c ≧ 50at% and d = 0] or [a ≧
5. The optical information recording medium according to claim 1, which is represented by a composition formula of b and c + d ≧ 50 at% and c ≧ d> 0]. 6. When the additive element M is an element having a smaller standard energy of oxide formation than Te, the composition of the protective layer is A (33.0) in the order of Te, M, and O in the Te-MO triangular composition diagram.
3, 0, 66.7), C (45.5, 0, 54.5), D (41.5, 8.
6. The optical information recording medium according to claim 5, wherein the optical information recording medium is in a composition range surrounded by (5, 50) and F (25, 25, 50). 7. The composition of the protective layer in the Te-MO triangular composition diagram is Te (M, O) in the order of A (33.3, 0, 66.7), B (40,
7. The optical information recording medium according to claim 6, wherein the optical information recording medium is in a composition range surrounded by (0, 60), E (33, 17, 50), and F (25, 25, 50). 8. The optical information recording medium according to claim 6, wherein M is any one of Ag, Au, Pt, Pd, and Cu. 9. When the additive element M is an element having a larger standard energy of formation of an oxide than Te, and its stoichiometric composition is represented by MO, the composition of the protective layer is Te-MO.
In the triangular composition diagram, A (33.3, 0, 66.
7), C (40, 0, 60), G (24, 24, 52), I (20, 2)
The optical information recording medium according to claim 5, which is in a composition range surrounded by (0, 60). 10. The composition of the protective layer is A (33.3,0,66.7), B (4) in the order of Te, M, O in the Te-MO triangular composition diagram.
The optical information recording medium according to claim 9, wherein the optical information recording medium is in a composition range surrounded by (0, 0, 60), H (22, 22, 56), and I (20, 20, 60). 11. The optical information recording medium according to claim 9, wherein M is any one of Zn, Mg, Sr, and Nb. 12. When the additive element M is an element having a larger standard energy of formation of an oxide than Te, and its stoichiometric composition is represented by M ₂ O ₃ , the composition of the protective layer is Te-M
In the -O triangular composition diagram, the order of Te, M and O is A (33.3, 0, 6
6.7), C (45.5, 0, 54.5), J (21.5, 21.5, 5
7. The optical information recording medium according to claim 5, wherein the optical information recording medium is in a composition range surrounded by 7) and L (18, 18, 64). 13. The composition of the protective layer is such that A (33.3, 0, 66.7) and B (4
The optical information recording medium according to claim 12, wherein the optical information recording medium is in a composition range surrounded by (0, 0, 60), K (20, 20, 60), and L (18, 18, 64). 14. M is Al, Bi, Cr, Dy, Eu,
11. The optical information recording medium according to claim 9, wherein the optical information recording medium is any one of Gd, Ho, La, Sb, Tb, Ti, and Y. 15. When the additive element M is an element having a larger standard energy of formation of an oxide than Te and its stoichiometric composition is represented by MO ₂ , the composition of the protective layer is Te-M
In the -O triangular composition diagram, the order of Te, M and O is A (33.3, 0, 6
6.7), C (45.5, 0, 54.5), M (24, 24, 52), O
6. A composition region surrounded by (16.7, 16.7, 66.6).
The optical information recording medium described in the above. 16. The composition of the protective layer is A (33.3, 0, 66.7), B (4) in the order of Te, M, and O in the Te-MO triangular composition diagram.
0, 0, 60), N (23, 23, 54), O (16.7, 16.7, 66.
16. The optical information recording medium according to claim 15, wherein the optical information recording medium is in a composition range surrounded by 6). 17. M is Si, Ge, Mn, Sn, Ti,
17. The optical information recording medium according to claim 15, which is one of Zr. 18. When the additive element M is an element having a standard oxide formation energy larger than that of Te and its stoichiometric composition is represented by M ₂ O ₅ , the composition of the protective layer is Te-M
In the -O triangular composition diagram, the order of Te, M and O is A (33.3, 0, 6
6.7), C (45.5, 0, 54.5), P (17.5, 17.5, 6
The optical information recording medium according to claim 5, wherein the optical information recording medium is in a composition range surrounded by 5) and R (15.5, 15.5, 69). 19. The composition of the protective layer is A (33.3, 0, 66.7), B (4) in the order of Te, M, and O in the Te-MO triangular composition diagram.
0, 0, 60), Q (16.5, 16.5, 67), R (15.5, 15.
19. The optical information recording medium according to claim 18, which is in a composition range surrounded by (5, 69). 20. The optical information recording medium according to claim 18, wherein M is any one of Nb, Sb, and Ta. 21. When the additive element M is an element having a larger standard energy of formation of an oxide than Te and its stoichiometric composition is represented by MO ₃ , the composition of the protective layer is Te-M
In the -O triangular composition diagram, the order of Te, M and O is A (33.3, 0, 6
6.7), C (45.5, 0, 54.5), S (16.5, 16.5, 6
7. The optical information recording medium according to claim 5, wherein the optical information recording medium is in a composition region surrounded by U and 14.5, 14.5, and 71. 22. The composition of the protective layer is A (33.3,0,66.7), B (4) in the order of Te, M, O in the Te-MO triangular composition diagram.
0, 0, 60), T (15.5, 15.5, 69), U (14.5, 14.
22. The optical information recording medium according to claim 21, which is in a composition range surrounded by (5, 71). 23. The optical information recording medium according to claim 21, wherein M is any one of Sc and W. 24. The optical element according to claim 1, wherein the information recording layer is formed of a phase-change material layer, and changes a phase between a plurality of optically detectable states in response to laser irradiation. Information recording medium. 25. Three layers including a first protective layer containing Te-O as a main component, an information recording layer, and a second protective layer containing Te-O as a main component. The optical information recording medium according to any one of claims 1 to 24, wherein a multilayer film including four layers obtained by further adding a metallic reflective layer (or a heat dissipation layer) to one layer is laminated. 26. The optical information recording medium according to claim 24, wherein the information recording layer is an alloy thin film containing Te or Sb. 27. A layer structure comprising: an information recording layer containing Te or Sb on a substrate; and a protective layer containing Te—O as a main component in contact with at least one surface of the information recording layer. A method for manufacturing an optical information recording medium, comprising:
The protective layer containing O as a main component is made of a Te target or Te.
TeO _X (0 ≦ x ≦ formed by solidifying a TeO ₂ powder mixture with
2) Forming using a target. At this time, when a Te target is used, a reactive sputtering method using a mixed gas of an inert gas and an oxygen gas or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas is used.
When a TeO _x (0 <x ≦ 2) target is used, a normal sputtering method using an inert gas according to the composition,
A method for producing an optical information recording medium by any of a reactive sputtering method using a mixed gas of an inert gas and an oxygen gas or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas. 28. A layer configuration in which an information recording layer containing Te or Sb is provided on a substrate, and a protective layer in contact with at least one of the surfaces of the information recording layer and containing Te—O as a main component and an additional element M is provided. Is a method for producing an optical information recording medium comprising: Te--O as a main component and M as a protective layer;
-M alloy or Te-M mixed powder target or Te
And TeO ₂ and M and M oxides (or M nitride or M
Te-MO- formed by solidifying the mixed powder of
(N) A target is formed using a Te-M alloy or a Te-M mixed powder target.
By a reactive sputtering method using a mixed gas of an inert gas and an oxygen gas or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas, and when using a Te-MO- (N) target, the composition is Optical information recording by either a normal sputtering method using an inert gas, a reactive sputtering method using a mixed gas of an inert gas and an oxygen gas, or a mixed gas of an inert gas, an oxygen gas and a nitrogen gas, depending on the situation Method of manufacturing a medium. 29. The additive M comprises a Group 0 element (Ar, Kr, Xe) and a Group Ib element (Cu, A
g, Au), Group IIa elements (Mg, Ca, Sr, Ba),
Group IIb element (Zn, Cd), Group IIIa element (Sc,
Y), Group IIIb elements (B, Al, Ga, In), Group IVa elements (Ti, Zr, Hf), Group IVb elements (C, Si, G
e, Sn, Pb), Va group elements (V, Nb, Ta), V
Group b element (N, Sb, Bi), VIa group element (Cr, M
o, W), Group VIIa element (Mn), Group VIII element (Fe, C
o, Ni, Ru, Rh, Pd, Os, Ir, Pt) lanthanoid element (La) rare earth element (Dy, Eu, Gd,
3. At least one selected from Tb).
29. The method for producing an optical information recording medium according to 7 or 28.