WO2000006391A1 - Information recording medium and information recording method - Google Patents

Abstract

An information recording medium comprising a substrate and a recording layer on the substrate, in which the recording layer is partly transformed between a crystalline state and an amorphous state by partly heating and cooling the recording layer, a signal is recorded in the recording layer by the partial transformation of the recording layer, and the recording layer contains oxygen.

Description

 Description Information recording medium and information recording method Technical field to which the invention pertains and prior art:

 According to the present invention, the recording layer can be partially transformed between a crystalline state and an amorphous state by heating and cooling, and a signal is recorded in the recording layer by a partial transformation of the recording layer. The present invention relates to an information recording medium and a method of recording information on the information recording medium.

 JP-A-61-25894 discloses that a mixture of tellurium and tellurium oxide is deposited as an oxygen-containing recording layer on a recording medium substrate by electron beam evaporation or sputtering.

 JP—A—2—25 25 57 77 discloses that a tellurium-containing compound is deposited as a recording layer containing oxygen on a recording medium substrate by sputtering in a mixed gas of argon and oxygen.

 JP-A-63-3-5868636 discloses that a compound containing germanium oxide and tellurium is deposited as a recording layer containing oxygen on a recording medium substrate by electron beam evaporation; and Disclosed is that a tellurium-containing compound is deposited as a recording layer containing oxygen on a recording medium substrate by sputtering in a mixed gas of argon and oxygen.

Problems to be Solved by the Invention, Means for Solving the Problems and Actions of the Problems: An object of the present invention is to suppress the change of recorded information with time, and to make clear reading of Z or recorded information clear. It is an object of the present invention to provide an information recording medium and an information recording method for ensuring the above. In particular, the recording layer in the crystalline state surrounding the recording layer in the amorphous state is prevented from growing and entering the crystal (epitaxial) inside the recording layer in the amorphous state, and / or the recording layer in the amorphous state It is an object of the present invention to provide an information recording medium and an information recording method in which the boundary between the recording layer in the amorphous state and the crystalline layer surrounding the recording layer in the amorphous state is clear and smooth.

In recent years, so-called optical disks have become widespread, and with this, more severe Optical discs have been used and stored under environmental conditions. Therefore, there is a need to further improve the reliability of the optical disk. From these viewpoints, various durability tests were conducted on the above-mentioned materials. As a result, once the disk on which information was recorded was stored for a long time in a high-temperature and humid severe environment, the signal quality such as jitter was reduced. A problem was found when it deteriorated. Inspection of this in detail revealed that a portion of the crystal phase grew epitaxially at the point where the amorphous mark was in contact with the crystal phase, and that the shape of the amorphous mark changed. Wakata. It was also found that no change occurred in the vicinity of the center of the amorphous mark, that is, in the portion not in contact with the crystal phase. In order to solve this problem, we investigated various materials and compositions of the recording film and tried to improve the stability of amorphous marks using a recording film with a large activation energy, but the same phenomenon also occurred . For these reasons, this phenomenon has not been solved even if the activation energy of the amorphous phase is increased to improve the thermodynamic stability of the amorphous phase, and this phenomenon has not been solved from a viewpoint that has been focused on so far. I knew I needed to do it. The present inventors have conducted various studies in order to solve the above-mentioned problem. As a result, it is extremely important to improve the interface between the amorphous mark and the crystalline phase of the recording film, and the oxygen content of the recording film It has been found that the above problem can be solved by modifying the amount.

A substrate and a recording layer on the substrate, wherein the recording layer can be partially transformed between a crystalline state and an amorphous state by being partially heated and cooled, and a signal is partially transmitted to the recording layer. In an information recording medium, which is adapted to be recorded in a recording layer by transformation, the fact that the recording layer contains oxygen means that the transformed portion changes, in particular, a record that has been transformed from a crystalline state to an amorphous state. Suppresses recrystallization of a part of the layer and suppresses the change of recorded information over time. As the recording layer of the present invention, Ge—Sb—Te system, In—Sb—Te system, Ag—In—Sb—Te system, MA—Ge—Sb—Te system (MA is Au, Cu, Pd, Ta, W, Ir, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, Mn, Fe, Ru, Co, Rh, Ni, Ag, At least one element of Tl, S, Se and Pt), Sn—Sb—Te, In—Se—Tl, In—Se—Tl—MB (MB Are Au, Cu, Pd, Ta, W, Ir, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, Mn, Fe, Ru, Co, Rh, Ni, Ag, Tl, S, Te and at least one of Pt Materials such as one element), Sn—Sb—Se can be used.

The ratio of the content of oxygen in the recording layer to the content of all atoms in the recording layer is 2 atoms. If it is less than / _0, it will be difficult to obtain the effect of stabilizing the recording marks formed by the partial transformation of the recording layer. On the other hand, if it is higher than 20 atomic%, it is difficult to easily realize the transformation between the crystalline state and the amorphous state. In order to further enhance the recording mark stabilizing effect, the content is preferably 3 to 15 atomic%, and more preferably 8 to 14 atomic%.

 The fact that the recording layer contains oxygen as an oxide stably retains oxygen in the recording layer, and diffuses components from an amorphous state part and / or a crystal part and / or into or into the recording layer, and Suppresses crystal growth from Z or crystal part into amorphous state part.

 When the recording layer contains Ge, Sb, and Te, it is preferable that the recording layer contains at least a part of Ge as an oxide. The content a of at least a portion of Ge as an oxide in the recording layer a, and the content b of other portions of Ge in the recording layer other than at least a portion of Ge as an oxide Is preferably in the range of 0.02≤aZ (a + b) ≤0.5.

 When the recording layer contains Ge, Sb, and Te, it is preferable that the recording layer contains at least a part of Sb as an oxide. The content c of at least a part of Sb as an oxide in the recording layer and the content d of other parts of Sb in the recording layer other than at least a part of Sb as an oxide Is preferably in the range of 0.01 ≤ c / (c + d) ≤ 0.2.

When the recording layer contains Ge, Sb, and Te, the content of each element is such that Ge is 10 to 30 atoms. /. 31) is a force in the range of 10 to 30 atomic% and Te is in the range of 40 to 80 atomic%, or Ge is 35 to 65 atomic%, 31) is 10 to 30 atomic%, and Te is 35 to 65 atomic%. When the content is in the range of atomic%, the phase change between the amorphous phase and the crystalline phase can be easily performed, and the information can be rewritten. In addition, other elements such as Au, Cu, Pd, Ta, W, Ir, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, 1 to 10 atoms of at least one of Mn, Fe, Ru, Co, Rh, Ni, Ag, Tl, S, Se, Pt and N. Addition in the range of / ₀ has the effect of increasing the crystallization temperature of the amorphous phase or increasing the activation energy.

 When the recording layer contains Ag, In, Sb, and Te, the recording layer preferably contains at least a part of In as an oxide. The content e of at least a part of In as the oxide in the recording layer and the other part of In in the recording layer other than at least a part of In as the oxide The relationship between the content f and the content f is preferably in the range of 0.01≤e / (e + f) ≤0.5.

 When the recording layer contains Ag, In, Sb, and Te, the recording layer preferably contains at least a part of Sb as an oxide. Content g of at least a part of Sb as an oxide in the recording layer, and content of other parts of Sb in a recording layer other than at least a part of Sb as an oxide Preferably, the relationship with h is in the range of 0.01 ≤ g / (g + h) ≤ 0.2.

When the recording layer comprises Ag, I n, S b, the Te, the content of each element, A g force S. 1 to 1 5 atoms _^0/0, I n force ';:! ~ 1 5 atoms _^0/0, S b is 45 to 80 atomic _^0/0, T e force S 20 to 40 atoms. In the range of / ₀ , a phase change between an amorphous phase and a crystalline phase can be easily performed, and information can be rewritten. In addition, other elements such as Au, Cu, Pd, Ta, W, Ir, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, Mn, Fe, Ru, Co, Rh , N i, T l, S, S e, P t, and at least one element of N is 1 to 10 atoms. Addition in the range of / ₀ has the effects of increasing the crystallization temperature of the amorphous phase or increasing the activation energy. The recording layer is partially heated by light beam or electron beam irradiation.

 By including oxygen in the recording film as described above, the oxygen or oxide inhibits at least partially the direct contact between the amorphous phase and the crystalline phase, thereby preventing the crystal growth like epitaxy. Therefore, it can be considered that the stability of the amorphous mark is improved.

The recording layer contains oxygen as an oxide in the recording layer. When a part of the recording layer is heated and melted, the viscosity of a part of the recording layer is increased by the oxide contained in the part of the recording layer. To A high degree of holding the surface tension of a portion of the recording layer to a high degree, whereby the part of the recording layer and the part of the recording layer that have been melted and then cooled so as to be solidified At least part of the boundary between the surrounding recording layer and the rest of the recording layer should be round and smooth so that one of the "0" and "1" states of the signal to be recorded is When one of the "0" state and the "1" state of the signal defined and recorded by at least a part of the boundary is recognized at least in part of the boundary, One of the "0" state and the "1" state of the signal is caused by at least a part of the boundary between the round and smooth part of the recording layer and the other part of the recording layer to the signal recording medium. Can be clearly and reliably defined when recording signals, and clearly and clearly recognized when reading signals from the recording medium. It can be. A part of the recording layer after being cooled so as to be solidified may be in an amorphous state, and the other part of the recording layer may be in a crystalline state, or the part after being cooled so as to be solidified. A part of the recording layer may be in a crystalline state, and the other part of the recording layer may be in an amorphous state.

 The above method is extremely effective especially when the recording density is increased. By forming a spiral groove or a plurality of concentric grooves on the substrate, a plurality of grooves that extend substantially in the circumferential direction and are arranged in parallel in the radial direction, and between the grooves, When there are a plurality of land areas extending in the circumferential direction and arranged in parallel in the radial direction, and at least one of the plurality of grooves and the plurality of land areas is a recording track for recording a signal. In addition, the smaller the radial spacing of the recording tracks, the higher the recording density. The above-described method is more effective when the distance between the recording tracks in the radial direction is Ιμπ or less, and is particularly effective when the distance is 0.7 μιη or less.

 In addition, the recording density increases as the area of the recording layer cooled so as to be solidified after heating and melting, that is, the minimum circumferential length of the recording mark decreases. If the minimum length of the recording mark in the circumferential direction is less than 0.7 μπι, the size of the mark shape distortion due to epitaxy-like crystal growth at the mark boundary with respect to the mark size will increase, and the change in the mark shape will increase. The above method is effective because the influence on the signal quality increases. It is more effective when the minimum length of the recording mark in the circumferential direction is 0.5 μπι or less.

A protective layer in contact with the recording layer, wherein the protective layer has at least one of oxygen and nitrogen; When oxygen is contained, diffusion of oxygen from the recording layer to the outside is suppressed, and oxygen is stably retained in the recording layer. When the protective layer contains oxygen, the diffusion of oxygen from the protective layer into the recording layer is suppressed because the recording layer contains oxygen. When the protective layer contains nitrogen, the change of the recording layer from the amorphous state to the crystalline state, that is, the crystal growth of the crystalline layer of the recording layer in the amorphous layer of the recording layer is suppressed.

It is preferable that the ratio of the nitrogen content in the protective layer to the content of all atoms in the protective layer is 1 atomic% or more and 50 atomic% or less. It is preferable that the protective layer comprises a Z n S and S i 0 _2. If the protective layer contains at least one of chromium oxide, tantalum oxide, aluminum oxide, and germanium nitride, component diffusion between the protective layer and the recording layer is suppressed, and the components of the recording layer are stable. When the protective layer contains nitrogen, its content is preferably 1 atomic% or more and 50 atomic% or less. Further, it is more preferable that the nitrogen content gradient in the film thickness direction in the region where the recording layer and the protective layer are in contact is 1 atomic% Z nm or more and 50 atomic% or less. Under these conditions, if the recording film is heated to a high temperature below the melting point by irradiation with an energy beam such as a laser beam, crystal nuclei are likely to be generated in a region where the protective layer and the recording layer are in contact with each other. The phase change from the phase to the crystalline phase, that is, the erasure of the recording mark becomes easy. In other words, by controlling the oxygen content of the recording layer and the nitrogen content of the protective layer, it is possible to obtain the storage stability of the amorphous mark at room temperature and the excellent erasing performance at high temperature. It becomes possible to obtain a rewritable medium. As a material for the protective film, a mixture of ZnS and SiO 2 is preferable because of its low thermal conductivity and good recording sensitivity. However, in this material, S is diffused into the recording layer by rewriting many times more than 100,000 times, and the optical constant of the recording layer may be changed to cause a decrease in reflectance. Chromium oxide, tantalum oxide, aluminum oxide, and germanium nitride can be used as the protective layer material. Of these, chromium oxide has a large optical constant and is excellent in that a large difference in the reflectance between the amorphous phase and the crystal layer can be obtained due to the multiple interference effect.However, it has a disadvantage that stress is large depending on the film forming conditions. . Tantalum oxide is excellent in that it has a large heat capacity and therefore can have a large cooling effect after the recording film is heated and melted. Has the disadvantage of becoming Aluminum oxide is extremely stable Oxide but weak adhesion to the recording film. Germanium nitride is excellent in terms of adhesion to the recording film, but has a drawback in that it is brittle in bulk and difficult to form by sputtering or the like because it is a material. Each of these protective layer materials has superior and inferior points, but by mixing them, there are combinations that eliminate their respective disadvantages and show only advantages. For example, chromium oxide and aluminum oxide, chromium oxide and germanium nitride, tantalum oxide and aluminum oxide, aluminum oxide and germanium nitride, and the like. Further, a material other than the above-mentioned materials may be added to the above-mentioned protective layer material. As a material other than materials described _{above, Ce 0 2, L a 2} 0 3, S i 0, ln 2 0 3, GeO, Ri GeO, P b 0, SnO, S N_〇 _2, B i ₂ 0 _3, Te_〇 _{2, S c 2 0 3,} Y 2 Rei_3, T i 0 _2, Z R_〇 _{2, V 2 0 5, Nb} 2 0 5, W0 2, W0 3, Cd S, Cd S e, Zn S _{e, I n 2 S 3,} I n 2 S e 3, S b one _{S 3, S b 2 S e} 3 Ga 9. S 3, G a 2 S e 3 ^ Ge S, Ge S e,

_{Ge S e 2, Sn S,} S n S 2, S n S e, S n S e 2, Pb S, Pb S e,

_{B i 2 S e 3, B} i 2 S 3, Mg F 2, Ce F 3, Ca F 2, Ta N, S i 3 N 4, A 1 N, C r N, BN, S i, T i B ₂ , B ₄ C, S i C, B, C and those having compositions similar to these can be used =

 The oxygen concentration is the ratio of the number of oxygen atoms to the total number of atoms in a unit volume. If the oxygen concentration in the recording layer changes in the thickness direction of the recording layer, the oxygen concentration comes into contact with the recording layer The change in viscosity and the change in reflectance between the surface of the recording layer and the inside of the recording layer can be set as desired, while the component diffusion characteristics between the layer and the surface of the recording layer are set as desired. Adjustment of the oxygen concentration in the recording layer may be performed by oxidizing the recording layer in a gas containing oxygen after the recording layer is formed, or an atmosphere gas during the deposition of the recording layer. The control may be performed by controlling the oxygen concentration of the above.

In the thickness direction of the recording layer, if the oxygen concentration increases from approximately the center of the recording layer to at least one of the surfaces on both sides of the recording layer, one of the layers that contacts the recording layer if the oxygen concentration increases. Maintains a high reflectance under the amorphous state at a point almost at the center of the recording layer while suppressing component diffusion between the recording layer and the surface of the recording layer.- A point almost at the center of the recording layer in the thickness direction of the recording layer From both sides, if the oxygen concentration increases towards each of the surfaces on both sides of the recording layer, it is noted that both layers are in contact with the recording layer. While suppressing the diffusion of components to and from the recording layer surface, the reflectivity under the amorphous state at a substantially central point of the recording layer is kept high.

 In the thickness direction of the recording layer, the oxygen concentration increases from the point substantially at the center of the recording layer toward at least one of the surfaces on both sides of the recording layer. Preferably, the increase is at least up to two times.

A recording layer disposed between the reflection layer and the substrate, wherein the recording layer has a first surface relatively close to the substrate in a thickness direction of the recording layer; When the second surface has an oxygen concentration near the first surface (or oxygen concentration at the first depth from the first surface), the oxygen concentration at the second surface (or approximately the first depth from the second surface) If the oxygen concentration at the first surface is lower than the oxygen concentration at the second surface, the oxygen concentration at the first surface increases toward the oxygen concentration at the second surface due to oxidation of the first surface by oxygen passing through the resin substrate. The oxygen concentration on the surface on both sides in the thickness direction of the layer is made uniform. The reflective layer is generally metallic, and has a lower oxygen permeability than a resin substrate. As a material used for the reflection layer, Au, Ag, Cu, A1, or a material containing at least one of these elements as a main component is preferable because the reflectance is extremely high. When these elements are used alone, the reflectance is extremely high, but the recording sensitivity is reduced due to the extremely high thermal conductivity. On the other hand, Ti, Cr, Co, Ni, Sb, Bi, In, Te, Se, Si, Ge, Pb, Ga, As, Zn, Cd, Sc, V, Mn, Fe, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir, Pt, Lanthanide element, Actinide element Those having at least one of them as the main components have low reflectance but extremely low thermal conductivity and good recording sensitivity. By mixing elements of the former group such as Au with elements of the latter group such as Ti, a reflective layer having high reflectance and low thermal conductivity can be obtained. Specifically, Au—Co, Au—Cr, Au—Ti, Au—Ni, Ag—Cr, Ag—Ti, Ag—Ru, Ag—Pd, Ag—Cu—Pd, A l—Ti, Al—Cr, Al—Co, Al—Ni, Al—Nb, and the like. Au-Ag and Au-Cu also have high reflectivity and can be reflective layers with low thermal conductivity. The oxygen concentration at the first surface (or oxygen concentration at a first depth from the first surface) is equal to the oxygen concentration at the second surface (or at a second depth approximately equal to the first depth from the second surface). (Oxygen concentration in the recording medium), the pair of recording layers is included in the information recording medium and the reflective layer is disposed relatively inward of the substrate in the information recording medium, and the information is recorded by recording and / or reproduction. When the temperature of a relatively inner point in the medium becomes higher than the temperature of a relatively outer point, oxidation of the second surface proceeds due to diffusion of oxygen from the protective layer, so that oxygen on the second surface is increased. The concentration increases toward the oxygen concentration on the first surface, and the oxygen concentration on both surfaces in the thickness direction of the recording layer is made uniform.

 In the thickness direction of the recording layer, if the oxygen concentration increases from a point approximately at the center of the recording layer toward the first surface, it is confirmed that oxygen passing through the substrate reaches a point approximately at the center of the recording layer. Suppress.

 In the thickness direction of the recording layer, if the oxygen concentration increases from the substantially central point of the recording layer toward the second surface, the pair of recording layers is included in the information recording medium and the reflective layer is included in the information recording medium. When the temperature at the relatively inner point in the information recording medium becomes higher than the temperature at the relatively outer point in the information recording medium due to recording and Z or reproduction, Suppresses the progress of oxidation at substantially the center of the recording layer.

When the recording layer has a first area in which information can be recorded and a second area in which only the pre-recorded predetermined information is reproduced, the oxygen content of the recording layer in the first area and the second area The difference from the oxygen content of the recording layer is 18 atoms. It is preferably at most / ₀ . After erasing a signal recorded in the first area and recording the signal a plurality of times, at least a part of the recording layer in the first area repeats a transformation between a crystalline state and an amorphous state a plurality of times. The difference between the oxygen content of the recording layer in the region and the oxygen content of the recording layer in the second region is 18 atoms. It is preferably at most / ₀ . The difference between the oxygen content of the recording layer in the first area where information can be recorded as described above and the oxygen content of the second area where only the predetermined information recorded in advance is reproduced is 18%. If it exceeds, the reflectance difference between the two will increase, and it will become difficult to reproduce the information in both the first and second areas in a similar manner. Usually, when a recording layer is formed by a method such as sputtering on an information recording medium having the first region and the second region as described above, the oxygen content of the first region and the second region immediately after the formation is The values are almost equal, and the reflectances of the two are almost the same, so that there is no hindrance to reproduction.However, the predetermined information in the second area is recorded by embossed pits. In this case, the physical shape is different from the first area in which only the grooves for recording and the gap between the grooves are formed, so that the way of oxygen diffusion inside the recording layer over time and the way of intrusion of oxygen from outside Can be different. Also, when recording is performed once or several times in the first area, only the recording layer in the first area undergoes an atomic arrangement change, so that oxidation is promoted as compared to the recording layer in the second area, Conversely, oxides can be eliminated. If the recording layer contains oxygen in advance, the above-mentioned problems are less likely to occur, and the difference between the oxygen content of the first area and the oxygen content of the second area after the time change or after multiple recordings is 18% or less. Can be held down.

 Heating and melting a part of the recording layer; and cooling and solidifying a part of the recording layer to be heated and melted to form a signal mark surrounded by another part of the recording layer other than the part of the recording layer. An information recording method for partially transforming the recording layer between a crystalline state and an amorphous state and recording a signal in the recording layer by partial transformation of the recording layer, the method comprising: The signal has a state of "0" and a state of "1", and one of the states of "0" and "1" to be recorded is a part of the recording layer and another of the recording layer. One of the "0" state and the "1" state defined and recorded by at least a part of the boundary between the parts is recognized in at least part of the boundary. In the report recording method,

The recording layer contains oxygen as an oxide in the recording layer, and when a part of the recording layer is heated and melted, the oxide contained in the part of the recording layer causes a part of the recording layer to be melted. The viscosity is maintained to a high degree to maintain the surface tension of a part of the recording layer to a high degree, whereby the part of the recording layer that has been melted and then cooled so as to be solidified and the recording layer If at least part of the boundary between the other parts of the signal is round and smooth, one of the "0" and "1" states of the signal to be recorded is at least one of the boundaries One of the "0" state and the "1" state of the signal, defined and recorded by the part, is recognized in at least a part of the boundary when the "0" state of the signal is recognized. One of the states and the state of "1" is that at least the boundary between one part of the round and smooth recording layer and the other part of the recording layer In part by, and as it can be clearly reliably defined when recording to the signal recording medium, it can be clearly recognized reliably and when reading from the signal recording medium. A part of the recording layer after being cooled so as to be solidified is in an amorphous state; The other part of the recording layer may be in a crystalline state, or a part of the recording layer after being cooled to be solidified may be in a crystalline state, and the other part of the recording layer may be in an amorphous state. Les ,. It is preferable that a part of the recording layer is heated and melted by light beam irradiation. The recording layer has a first recording layer (4b) and a second recording layer (4a), and the oxygen concentration is sharp between the first recording layer and the second recording layer in the recording layer thickness direction. (Compared to the change in oxygen concentration in the first and second recording layers), the average oxygen concentration in the first recording layer, averaged along the thickness direction of the recording layer, is And the thickness of the first recording layer may be greater than the thickness of the second recording layer. The recording layer may have a plurality of second recording layers, and the first recording layer may be disposed between the second recording layers.

BRIEF DESCRIPTION OF THE DRAWINGS:

 FIG. 1 is a schematic sectional view showing the structure of a phase change (transformation) type information recording medium according to an embodiment of the present invention.

 FIG. 2a is a cross-sectional view of a radially cut substrate showing a groove of the substrate on which the recording layer according to the present invention is disposed and lands protruding from the groove.

 FIG. 2b shows two embodiments of a substrate on which a recording layer according to the invention is arranged (a plurality of concentric grooves extending substantially radially parallel to a radial direction and a plurality of lands). FIG. 2 is a front view showing a concentric surface shape to be formed, and a spiral surface shape that forms a plurality of grooves and a plurality of lands that are arranged in the radial direction and that extend substantially in the circumferential direction. FIG. 3 is a schematic diagram showing a relationship between a recording mark and one of a “1” state and a “0” state of a signal to be read from or recorded by the recording mark. When the level of the recording signal changes, one of the "1" state and the "0" state of the signal is read and recorded.

 FIG. 4 is a schematic partial cross-sectional view showing that the recording layer may be composed of a plurality of layers so that the oxygen concentration differs in the thickness direction.

 Figure 5 shows the relationship between the oxygen concentration, the shortest recorded mark length, and the jitter after the acceleration test.

Figure 6 shows the relationship between oxygen concentration, track pitch and jitter after the acceleration test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS:

 Hereinafter, the present invention will be described in detail with reference to Examples.

 [Example 1]

It is made of a transparent material (eg, polycarbonate resin, glass, etc.) having a diameter of 120 mm and a thickness of 0.6 mm in a substantially circumferential direction (ie, concentric or spiral) as shown in FIG. A substrate 1a was prepared in which a radially parallel groove 1 'extending and a radially parallel land portion 1 "extending substantially circumferentially were prepared in advance. In one embodiment, a groove 1' The radial distance between the center and the center of the adjacent land 1 "was 0.74 / m. This substrate 1a was placed in a first sputtering chamber in a sputtering apparatus having a plurality of sputtering chambers and excellent in uniformity of layer thickness and reproducibility. Using a mixture of Z n S and S i O ₂ as data one target, a thickness of 90 nm by sputtering rings in argon gas (Z n S) ₈₀ Mo and (S I_〇 _{2) 20} (80 and 20 %) Of the first overlay layer 2 was formed on the substrate 1a. Then, after moving the substrate to a second sputtering chamber, C r ₂ 0 ₃ was used, the first protective layer 3 of C r ₂ O ₃ of 20 nm thick was laminated by sputtering in an argon gas as a target Was. After moving this substrate to the third sputtering chamber,

^{A § 2. 5 G e 20 S} b 22. 5 T e 55 (2 · 5, 2 0, 22. 5, 55 atomic

%) As a sintered body, the recording layer 4 was laminated with a thickness of 16 _nm by sputtering in argon gas. Then, a mixed gas of argon and oxygen having an oxygen partial pressure of 10% was introduced into the third sputtering chamber at a gas flow rate of 200 SCCM for a certain period of time to oxidize the surface of the recording layer 4. Next, the substrate was moved to the fourth sputtering chamber, and a thickness of 18 nm was formed by sputtering in the same manner as in the formation of the first overlay layer.

A second protective layer 5 of (ZnS) ₈₀ (Sio2) 20 (80 and 20 is mol%) was laminated. Then, using the A 1 C r alloy fifth sputtering chamber as data one Ggetto, A 1 94 C r ₆ first thickness of the reflective layer 6 35 nm (atomic. / ₀ and 94 and 6) by sputtering Was laminated. Finally with A 1 T i alloy as Targ Tsu preparative sixth sputtering chamber chamber by sputtering A 1 ₉₉ T i! (99% and 1 are% by weight) of the second reflective layer 7 having a thickness of 35 nm. The substrate on which the protective layer, the reflective layer, and the overlay layer are laminated is removed from the sputtering apparatus, and an ultraviolet curable resin is placed on the uppermost layer The protective layer 8 was applied by spin coating.

Similarly to the other piece of the same substrate 1 on b (Z n S) go ( S i 0 2) 2 o (8 0 the molar _^0/0 and 20) first overlay layer of 2 ', 〇 ₂ 0 ₃ protective layer _{3 ', Ag 2. 5 G} e 20 S b 22. 5 recording layer 4 Te 55',

_{(Z n S) 80 (S} i 0 2) 20 (80 and mole _^0/0 and 20) the second protective layer 5 of the '

A 1 ₉₄ Cr ₆ (94 and 6 are atoms. / ₀ ) first reflective layer 6, A 1 _{99 Tix} (99 and 1 are% by weight) second reflective layer 7 ′, UV cured The resin protective layer 8 'was laminated, and the two substrates la and 1b were opposed to each other with the ultraviolet curable resin protective layers 8 and 8' facing inside, and were bonded together with the adhesive layer 9. At this time, if the diameter of the adhesive layer was set to 118 mm or more, peeling of the adhesive layer due to impacts such as dropping became difficult to occur. The same oxidation treatment as that of the recording layer 4 was performed on the recording layer 4 ′.

 After the recording layers 4 and 4 'were formed, several samples of the discs were prepared by changing the oxygen content or oxygen concentration in the recording layer by changing the time during which a mixed gas of argon and oxygen was added to the recording layer. First, initialization was performed by irradiating a laser beam having an elliptical beam with a wavelength of 810 nm, a beam major axis of 75 mm, and a minor axis of 1 mm. Next, the disc is rotated to a linear velocity of about 6 m / s, and a semiconductor laser beam with a wavelength of 660 nm is condensed by an NA0.6 objective lens, irradiated onto the recording layer through the substrate, and recorded and reproduced. Was done. For the recording, a random signal modulated with 8-16 modulation was recorded using a waveform in which the laser power was modulated between 111111 and 5111 \ ^. A record mark was formed at a power of llmW, and direct overwriting was performed to erase with a power of 5mW. However, a multipulse recording waveform that divides recording pulses other than the shortest mark into a plurality was used. Recording was performed both on the groove and on the land.

After measuring the jitter of the signal recorded as described above, an acceleration test was performed in which the disc was left in an environment of 90 ° C and 80% for 100 hours, and the jitter was measured again after the acceleration test. When the oxygen content or concentration in the recording layer was changed, the jitter before and after the acceleration test was as follows. The oxygen content in the recording layer was measured by the Auger electron spectroscopy. 【table 1】

記録層の酸化処理を確実に行わなかったサンプル 8は、 サンプル 1〜 7に比べ て加速試験後のジッターが著しく増大した。 また、 混合ガス流入時間を最も長く したサンプル 1は、 加速試験前後でジッターの変化はなかったが、 初期ジッター がサンプル 2 8に比べて著しく悪くなつた。 なお、 上記サンプル 1 7では記 録層の成層後に酸素を含む混合ガスを流入させて記録層の酸化処理を行ったが、 アルゴンと酸素の混合ガス雰囲気中で記録層をスパッタリングにより形成するこ とによっても記録層を酸化させることができる。

In Sample 8, in which the recording layer was not oxidized, the jitter after the accelerated test was significantly increased as compared with Samples 1 to 7. In sample 1, which had the longest mixed gas inflow time, the jitter did not change before and after the accelerated test, but the initial jitter was significantly worse than in sample 28. In Sample 17, the recording layer was oxidized by flowing a mixed gas containing oxygen after the recording layer was formed.However, the recording layer was formed by sputtering in a mixed gas atmosphere of argon and oxygen. Can also oxidize the recording layer.

 In the above, the Ge content is 10 30 atoms. /. The Sb content is 10 to 30 atoms. /. When using a recording layer in which the Te content is changed in the range of 4080 at%, or the Ge content is 35 65 atoms. /. The Sb content is 10 30 atoms. /. The same results as above were obtained when using a recording layer in which the Te content was changed in the range of 3565 at%.

 Similar results were obtained when a recording film containing no Ag was used, or when a recording film was used in which the Ag content was changed in the range of 110 atomic%.

Further, a part or all of Ag is replaced to form Au, Cu Pd, Ta, W, IrScYTi, Z, VNbCr, MoMn, Fe, RuCoRhNi, Ag 110 atoms of at least one element of TlS, Se, Pt and N. Similar results were obtained when the addition was in the range of / ₀ . When forming the recording layer 4, a 2 nm-thick second recording layer 4a was formed using a mixed gas of argon and oxygen as a sputtering gas.

Modified to form the first recording layer 4 b with a thickness of 16 nm

When the second recording layer 4a having a thickness of 2 nm is formed again by changing to a mixed gas of oxygen and oxygen, and the oxidation treatment is not performed by flowing the argon-oxygen mixed gas after the formation of the recording layer, the reflectivity of the disk is reduced. A higher effect was obtained. When the average oxygen content of the first and second recording layers is adjusted from 2 atomic% to 20 atomic% by changing the oxygen partial pressure of the mixed gas when forming the second recording layer, the jitter due to the acceleration test The rise was similar to Table 1. When the oxygen content of the first recording layer was 1/3 or less of the oxygen content of the second recording layer, the disk reflectance increased by 2%. When the second recording layer 4a was formed on only one of the first recording layers 4b, characteristics similar to those formed on both sides were obtained. Similar characteristics were obtained when the film thickness of the second recording layer 4a was changed in the range of 1 to 10 nm.However, when the film thickness was increased to 5 nm or more, the recording sensitivity deteriorated, and it was necessary for recording. Power increased by about 1 mW.

 [Example 2]

The same substrate 1a as in Example 1 was placed in a first sputtering chamber in a sputtering apparatus having a plurality of sputtering chambers and having excellent layer thickness uniformity and reproducibility. Using a mixture of Zn S and S i O ₂ as data one target, a thickness of 90 nm by sputtering in argon gas _{(Z n S) 80 (S} i 0 2) 20 (80 A and 20 mole ⁰ / ₀ ) was formed on the substrate 1a. Next, after moving this substrate to the second sputtering chamber, Cr ₂ O ₃ was used as a target, and a 20 nm-thick first protective layer 3 of Cr ₂ O ₃ was deposited by sputtering in argon gas. did. After moving this substrate to the third sputtering chamber,

_{Ag 2. 5 G e 2 0 S} b 2 2. 5 T e 5 5 (2. 5, 20, 22. 5, 55 atomic%) as a sintered body of the recording layer 4 by sputtering in an argon gas _Was laminated with a thickness of 16 _nm . Thereafter, the substrate was moved to an oxide formation chamber, and left for a certain period of time in an oxygen atmosphere to oxidize the recording layer 4. Next, the substrate was moved to the fourth sputtering chamber, and a thickness of 18 nm was formed similarly to the formation of the first overlay layer.

(Zn S) ₈₀ (S I_〇 _{2) 2} o Sno the second protective layer 5 (80 and 20 and the mole _^0/0),. The layers were laminated by the cutter. Then, using the A 1 C r alloy fifth sputtering chamber as Ta' target was laminated first reflective layer 6 of A l ₉₄ C r _{6 (94} and atomic% and 6) in a thickness of 35 nm by sputtering . Finally, in the sixth sputtering chamber

An A 1 Ti alloy was used as a target, and a second reflective layer 7 having a thickness of 35 nm was deposited by sputtering with A 1 ₉₉ Ti 丄 (99 and 1 being% by weight). The substrate on which the overlayer, the protective layer, the recording layer, and the reflective layer were laminated was taken out of the sputtering apparatus, and the ultraviolet curable resin protective layer 8 was formed on the second reflective layer 7 by spin coating. Similarly, on another similar substrate 1 b,

_{(Z n S) 8 0 (} S i 02) 2 o (80 and 20 mole _^0/0 and) first over one laid layer 2 ', the protective layer 3 of C r ₂ O _3', recording layer 4 ' , first the _{(Zn S) 80 (S i} O 2) 20 ( atomic _^0/0 94 6) second protective layer 5 ,, a 1 94 C r ₆ (8 0 mol% and 20) 1 Reflective layer 6 ', A 1 ₉₉ Ti! (99 and 1 are weight./ ₀ ) The second reflective layer 7 ′ and the ultraviolet curing resin protective layer 8 ′ are sequentially laminated, and the two substrates are placed with the ultraviolet curing resin protective layers 8 and 8 ′ inside. And bonded together by the adhesive layer 9. At this time, if the diameter of the adhesive layer was set to 118 mm or more, peeling of the adhesive layer due to impact such as dropping was less likely to occur. The same oxidation treatment as that for the recording layer 4 was performed on the recording layer 4 '.

After the formation of the recording layers 4 and 4 ', the oxygen partial pressure and the storage time were changed, and the content of Ge oxide and Sb oxide in the recording layer was changed for each of a plurality of types of disc samples. After preparing a plurality of sample disks, each sample disk was initialized in the same manner as in Example 1, and a drive signal was used to record a random signal 8-6-1 modulated. After that, an acceleration test was performed in which these disks were left in an environment of 70% and 90% for 40 days.After the acceleration test, a playback test was performed on the drive, and the number of disks whose error rate was at least twice as high as before the test Was examined. Furthermore, for each sample after initialization, recording of a 8-16 modulated random signal was repeatedly performed on the same portion of the disk using a drive, and the number of times a reproduction or recording error occurred was examined. Table 2 shows the number of disks where the error more than doubled when the content of Ge oxide and Sb oxide in the recording layer was changed. When the content of Ge oxide and Sb oxide in the recording layer was changed, the number of repetitive recordings was as shown in Table 2. Unagi. The content of the Ge oxide and the Sb oxide in the recording layer was measured using an XPS apparatus, and the peaks of the XPS spectra of Ge and Sb were obtained. In Table 2, a is the content of Ge in oxide state, b is the content of Ge in non-oxide state of metal or alloy, c is the content of Sb in oxide state, and d is It is the content of Sb in the non-oxide state of the metal or alloy.

 [Table 2]

記録層の酸化処理を確実に行わなかったサンプル 7は、 サンプル：！〜 6に比べ て加速試験後のエラ一レートが著しく増大し、 10枚中 8枚が 2倍以上にエラー レートが増大しただけでなく、 そのうちの 4枚で再生そのものが著しく困難にな る現象が生じた。

Sample 7 in which the recording layer was not oxidized was sample:! The error rate after the accelerated test was significantly increased compared to that of ~ 6, and the error rate was increased more than twice in 8 out of 10 images, and the reproduction itself became extremely difficult in 4 of them. Occurred.

In the above, the Ge content is 10 to 30 atom%, and 31) the content is 10 to 30 atom. /. , T e when the content was used a recording layer was changed within a range of 40 to 80 atomic%, or G e content of 35 to 65 atomic%, S b content of 10-30 atomic _^0/0, T The same results as above were obtained when using a recording layer in which the e content was changed in the range of 35 to 65 atomic%.

 Similar results were obtained when a recording film containing no Ag was used, or when a recording film was used in which the Ag content was changed in the range of 1 to 10 atomic%.

Further, a part or all of Ag is substituted to Au, Cu, Pd, Ta, W, Ir, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, Mn, F e, Ru, Co, At least one element of Rh, Ni, Ag, Tl, S, Se, Pt and N is 1 to 10 atoms. Similar results were obtained when the addition was in the range of / ₀ .

 [Embodiment 3]

The technical limitation, except that the radial sense between the center of the groove 1 'and the center of the adjacent groove was 0.75 // m, was the same as in Example 1, except that the substrate 1a was It has a sputter chamber, and was placed in the first sputter chamber in a sputter apparatus with excellent layer thickness uniformity and reproducibility. Using a mixture of Z n S and S i 0 ₂ as a target, a thickness of 90 nm by sputtering in argon gas _{(Z n S) 80 (S} i 0 2) 2 o (80 molar% and 20) The first protective layer 2 was formed on the substrate 1a. Then, after moving the substrate to a second sputtering chamber, a target _{Ag 4 I n 7 S b 62} T e 2 7 (4, 7, 6 2, 2 7 atomic ./.) As a sintered body, argon The recording layer 4 was laminated with a thickness of 20 nm by sputtering in a gas. Thereafter, the substrate was moved to an oxide formation chamber, and left in an oxygen atmosphere for a certain time to oxidize the recording layer 4. Next, the substrate is moved to the third sputter chamber, and a thickness of 20 nm is formed in the same manner as the formation of the first protective layer.

_{(Z n S) 80 (S} it 02) 20 ( mol. / ₀₎ a second protective layer 5 is laminated in. Then, using the A 1 T i alloy as Taggetto fourth sputtering chamber, A 1 _{9 9} T i E (9 9 1 The weight. / ₀₎ a reflective layer 7 was laminated with a thickness of l OO nm. The substrate on which the protective layer, the recording layer, and the reflective layer were laminated was taken out of the sputtering apparatus, and the ultraviolet curable resin protective layer 8 was applied on the uppermost layer by spin coating.

Similarly, the other piece of the same substrate 1 on _{b (Z n S) 8 0} (S I_〇 _{2) 2 0} (80 and moles. / ₀ and 20) first protective layer 2 ', the recording Tier 4 ',

_{(Z n S) 8 0 (} S i O 2) 20 (80 molar and 20. / ₀₎ a second protective layer 5 A 1 _{9 9} of T i! (The weight of 9 and 1 is weight. /.) Reflective layer 6 ′ and UV curable resin protective layer 8 ′ are sequentially laminated, and two substrates face each other with UV curable resin protective layers 8 and 8 ′ inside. Then, bonding was performed using the adhesive layer 9. At this time, if the diameter of the adhesive layer was set to 118 mm or more, peeling of the adhesive layer due to impacts such as dropping became difficult to occur. The same oxidation treatment as that of the recording layer 4 was performed on the recording layer 4 ′.

The technical limitation, except that recording was performed only on the groove, was as described in Example 1. After measuring the jitter of the signal recorded as described above, the disc was placed in an environment at 80 ° C and 90%. An acceleration test in which the sample was allowed to stand for 200 hours was performed below, and the jitter was measured after the acceleration test. When the oxygen partial pressure and the storage time were changed and the content of In oxide and Sb oxide in the recording layer was changed, the jitter before and after the acceleration test was as follows. The content of In oxide and Sb oxide in the recording layer was measured using an XPS apparatus, and the XPS spectra of In and Sb were separated by peaks. In Table 3, e is the In content in the oxide state, f is the In content in the non-oxide state of the metal or alloy, g is the Sb content in the oxide state, and h is The content of Sb in the non-oxide state of the metal or alloy.

 [Table 3]

記録層の酸化処理を確実に行わなかつたサンプル 7は、 サンプル 1〜 6に比べ て加速試験後のジッターが著しく増大した。 また、 放置時間を最も長くしたサン プル 1は、 加速試験前後でジッターの変化はなかったが、 初期ジッターがサンプ ル 2〜 7に比べて著しく悪くなつた。

In Sample 7, in which the recording layer was not oxidized, the jitter after the accelerated test was significantly increased as compared with Samples 1 to 6. In Sample 1, which had the longest standing time, the jitter did not change before and after the accelerated test, but the initial jitter was significantly worse than Samples 2 to 7.

 The above sample :! In Nos. 6 to 6, the recording layer was oxidized by leaving the recording layer in an oxygen atmosphere.However, the recording layer was also oxidized by forming the recording layer in a mixed gas atmosphere of argon and oxygen. Can be.

 In the above, the Ag content is 1 to 15 atoms. /. The content is 1 to 15 atom%, and the Sb content is 45 to 80 atom. /. The same results as described above were obtained when using a recording layer in which the Te content was changed in the range of 20 to 40 atomic%.

In addition, other elements such as Au, Cu, Pd, Ta, W, Ir, Sc, Y, Ti, Zr, V, Nb, Cr, Mo, Mn, Fe, Ru, Co, Rh, Ni, T, and at least one element of S, Se, Pt, and N are 1 to 10 Similar results were obtained with the addition in the range of atomic%.

 [Example 4]

The same substrate 1a as that of Example 1 was placed in a first sparch chamber in a sputtering apparatus having a plurality of sputter chambers and having excellent film thickness uniformity and excellent reproducibility. Using a mixture of ZnS and SiO ₂ as a target, a 90 nm thick

(Z n S) so (S i 0 2) 20 ( mol _^0/0) to form a first overlay layer 2. After the next Ide The substrate was moved to a second sputtering chamber, a C r ₂ 0 ₃ used as a target, to form a C r ₂ 0 first protective layer 3 of ₃ of 20 nm thick in argon gas. After moving this substrate to the third sputtering chamber,

Ag _2. As _{5 Ge 20 S b 22. 5} T e 55 ( atom. / ₀₎ sintered body was formed in the thickness of the recording film 4 of 16 nm in an argon gas. Thereafter, a recording gas 4 was oxidized by flowing a mixed gas of argon and oxygen having a partial pressure of oxygen of 10% into the third sputtering chamber at a gas flow rate of 200 SCCM for a certain period of time. Next, the substrate was moved to the fourth sputtering chamber, and a thickness of 18! ! ^ Formed a second protective layer 5 of n S -S i O ₂ —N. Next, using the A 1 Cr alloy as a target in the fifth sputtering chamber,

A 1 ₉₄ C r ₆ (atom. / ₀₎ and the first reflective layer 6 was formed with a thickness of 35 nm. Finally with A 1 T i alloy sixth sputtering chamber interior as Tagge' bets, and the second reflection layer 7 of A 1 ₉₉ T i E (wt. / ₀₎ to 35 nm formed. The laminated substrate was taken out from the sputtering apparatus, and an ultraviolet curable resin protective layer 8 was formed on the uppermost layer by spin coating. Similarly, on another similar substrate 1 b

_{(ZnS) 8 0 (S i} O 2) 20 ( mol%) first overlay layer 2 ', C r ₂ 0 ₃ coercive Mamorumaku 3', recording layer 4 ', Z n S- S i 0 2 - N a 2 Protective layer 5 ', A 1 ₉₄ Cr ₆ (atomic%) First reflective layer 6', Al ₉₉ T ii (wt%) Second reflective layer 7 ', UV curable resin Protective layer 8' Then, the two substrates were bonded together with the adhesive layer 9 with the UV-curable resin protective layers 8 and 8 ′ inside. At this time, if the diameter of the adhesive layer was set to 118 mm or more, peeling of the adhesive layer due to an impact such as dropping became difficult to occur. Prepare several types of discs as described above, and 8-16 modulated using a drive After recording a random signal and measuring the error rate, an acceleration test is performed in which the disc is left for 100 hours in an environment of 90 ° C and 80%, and after the acceleration test, the error rate reproduction error at the same location is performed. After measuring the error rate, the random signal was overwritten at that location and the error rate (overwrite error rate) was measured. Oxygen-containing organic content in the recording film is kept constant at 8 atomic%, Z n S- S i 0 2 - by changing the N nitrogen concentration in the mixed gas of argon emissions and nitrogen during deposition of the second protective layer Z n S- S i O ₂ - when changing the n nitrogen content of the second protective layer, disc number of sheets after the acceleration test Erareto is increased more than 2 times were as follows. The oxygen content in the recording film and the nitrogen content in the second protective layer were measured by using forge electron spectroscopy.

 [Table 4]

第 2保護層中の窒素含有量を 6 0原子％とした場合には 1 0枚中 9枚のディス クで再生エラーレートが 2倍以上になっただけでなく、 そのうちの 8枚で再生そ のものが極めて困難になる現象が生じた。 窒素含有量 5 0原子。 /₀、 2 5原子％の 場合にも再生エラーが 2倍以上になるディスクが生じたが、 これらのディスクに おいては再生が困難になるような現象は生じなかった。

When the nitrogen content in the second protective layer was 60 atomic%, the reproduction error rate not only doubled or increased with nine out of ten discs but also with eight of those discs. A phenomenon that made it extremely difficult. Nitrogen content 50 atoms. In some cases, the reproduction error was more than doubled in the case of / ₀ , 25 atomic%, but no phenomenon that made reproduction difficult in these disks occurred.

 [Example 5]

After recording on a disk manufactured in the same manner as in Example 1 with the shortest mark length changed, an acceleration test was performed in which the sample was left for 100 hours in an environment with a temperature of 90% and a relative humidity of 80% to accelerate. After the test, the jitter was measured. The radial distance between the center of the groove 1 'and the land 1 "adjacent to it is 0.74 μππ, and recording is performed both on the groove and on the land. I got it. The modulation method is a mark position method in which information of 1 is placed at the mark position and information of 0 is placed at other positions, and information 1 is placed at the end of the mark and information is placed at other positions. We examined both of the mark edge methods. When the oxygen content in the recording film was changed, the jitter after the acceleration test changed as shown in FIG.

 [Example 6]

 It is made of a transparent material (eg, polycarbonate resin, glass, etc.) with a diameter of 120 mm and a thickness of 0.6 mm, as shown in FIG. 2 (ie, on a concentric or spiral surface). A radially extending groove 1 ′ extending substantially in the circumferential direction and a radially extending land 1 ″ extending substantially in the circumferential direction are formed, and the center of the groove 1 ′ and the land adjacent thereto are formed. Several types of substrates 1a having different distances from the center of 1 "were prepared. After recording on these substrates with the shortest mark length of 0.7 μηι on a disk fabricated in the same manner as in Example 1, the disk was placed in an environment at a temperature of 90 ° C and a relative humidity of 80% for 100 hours. An acceleration test in which the sample was left for a while was performed, and the jitter was measured after the acceleration test. The modulation method is a mark position method in which information of 1 is placed at the position of the mark and information of 0 is placed at the other position, and information 1 is placed at the end of the mark and information of 0 is placed at the other position. Both mark edge methods were studied.

 When the oxygen content in the recording film was changed, the jitter after the acceleration test changed as shown in FIG.

 [Example 7]

It is made of a transparent material (eg, polycarbonate resin, glass, etc.) with a diameter of 120 mm and a thickness of 0.6 mm, as shown in FIG. 2 (ie, on a concentric or spiral surface). Radially juxtaposed grooves 1 ′ extending substantially in the circumferential direction and radially juxtaposed lands 1 ″ extending substantially in the circumferential direction are formed. Further, these grooves 1 ′ or lands 1 ″ are formed. In the circumferential direction, it is divided into a plurality of groove portions or a plurality of land portions, and in the region between the groove portions or the land portions, the groove 1 ′ or the land portion 1 ″ extends in the circumferential direction along which it extends. was prepared substrate 1 _a of the embossed pits are formed indicating, for example Adoresu information substantially along. both on the substrate, to prepare a disk in the same manner as in example 1, the groove 1 'and the land portion 1 " Record track After recording 10,000 times on multiple recording tracks, an acceleration test was performed in which the device was left in an environment at a temperature of 90 ° C and a relative humidity of 80% for a certain period of time. Oxygen content in the recording layer of the groove 1 'or land 1 "area where the recording was performed 10,000 times, that is, the first area where information can be recorded, and the address The relationship between the oxygen content in the recording layer of the area where the emboss pits indicating information and the like are formed, that is, the second area where only predetermined information is reproduced, and the reflectance of the first area and the second area is as follows. Has changed to

 [Table 5]

 Leaving time 1st area 2nd area 1st area and 2nd area 1st area and 2nd area Oxygen-containing oxygen content difference of oxygen content Difference in reflectance

 0 hours 4% 2% 2% 0%

 50 hours 8% 2% 6% 0 ~; 1%

100 hours 10% 2% 8% 1%

 200 hours 1 5% 2% 13% 2%

 300 hours 20% 3% 1 7% 4%

 500 hours 22% 4% 1 8% 5%

 1000 hours 25% 5% 20% 8%

Claims

The scope of the claims 1. having a substrate and a recording layer on the substrate, wherein the recording layer can be partially transformed between a crystalline state and an amorphous state by being partially heated and cooled; An information recording medium, which is adapted to be recorded in a recording layer by dynamic transformation, wherein the recording layer contains oxygen.  2. The information recording medium according to claim 1, wherein the recording layer includes at least one of Te and Se as a main component of the recording layer.  3. The information according to any one of claims 1 and 2, wherein a ratio of an oxygen content in the recording layer to a content of all atoms in the recording layer is 2 to 20 atomic%. recoding media.  4. The information recording medium according to claim 1, wherein the recording layer contains oxygen as an oxide.  5. The information recording medium according to claim 1, wherein the recording layer contains Ge, and the recording layer contains at least a part of Ge as an oxide.  6. The content a of at least a portion of Ge as the oxide in the recording layer, and other portions of Ge in the recording layer other than at least a portion of Ge as the oxide. The information recording medium according to claim 5, wherein a relationship between the content b of the information recording medium and the content of the recording medium is within a range of 0.02≤a / (a + b) ≤0.5.  7. The information recording medium according to claim 1, wherein the recording layer contains Sb, and the recording layer contains at least a part of Sb as an oxide.  8. The content c of at least a portion of Sb as the oxide in the recording layer, and the other portion of Sb in the recording layer other than at least a portion of Sb as the oxide. 8. The information recording medium according to claim 7, wherein the relationship between the content d of d and the content d is within the range of 0.01≤c / (c + d) ≤0.2.  9. The recording layer according to claim 1, wherein the recording layer includes Ag, In, Sb, and Te, and the recording layer includes at least a part of In as an oxide. Information recording medium according to (1). 10. The content e of at least a part of In as the oxide in the recording layer, The relationship between the content f of the other part of In in the recording layer except for at least a part of I η as an object is 0.0 1 ≤ e Z (e + f) ≤ 0.5. The information recording medium according to claim 9, wherein  11. The recording layer according to claim 1, wherein the recording layer includes Ag, In, Sb, and Te, and the recording layer includes at least a part of Sb as an oxide. Information recording medium according to (1).  12. The content g of at least a part of Sb as the oxide in the recording layer, and other parts of Sb in the recording layer other than at least a part of Sb as the oxide. The information recording medium according to claim 11, wherein the relationship between the content h and the content h is within the range of 0.01≤gZ (g + h) ≤0.2.  13. The information recording medium according to claim 1, wherein the recording layer is partially heated by light beam irradiation.  14. The recording layer contains oxygen as an oxide in the recording layer, and when a part of the recording layer is heated and melted, the oxide contained in a part of the recording layer causes the oxide to be included in the recording layer. The surface tension of a part of the recording layer is maintained at a high level by maintaining the viscosity of the recording layer to a high degree, whereby the part of the recording layer that has been melted and then cooled so as to be solidified and the recording layer are maintained. 2. The information recording medium according to claim 1, wherein at least a part of a boundary between the part and the other part of the recording layer surrounding the part is round and smooth.  15. The recorded signal has a state of "0" and a state of "1", and one of the states of "0" and "1" recorded is at least partially defined by the boundary. 15. A defined and recorded one of the "0" and "1" states is recognized at least partially at the boundary. Recording media.  16. A part of the recording layer after being cooled so as to be solidified is in an amorphous state, and the other part of the recording layer is in a crystalline state. Recording media. 17. The recording layer according to claim 13, wherein a part of the recording layer after being cooled so as to be solidified is in a crystalline state, and another part of the recording layer is in an amorphous state. By the recording medium _c 18. The substrate comprises a plurality of substantially circumferentially extending and radially parallel grooves; A plurality of lands extending substantially in a circumferential direction between the grooves and arranged in a radial direction, at least a plurality of grooves arranged in a radial direction and a plurality of lands arranged in a radial direction The information recording medium according to claim 1, wherein one forms a recording track on which a signal is recorded.  19. The information recording medium according to claim 18, wherein a radial distance between the recording tracks is 1 x m or less.  20. The information recording medium according to claim 18, wherein a radial distance between the recording tracks is 0.7 zm or less.  21. The information recording medium according to claim 18, wherein a part of the recording layer that is cooled so as to be solidified after being melted has a substantially minimum circumferential length of 0.7 μηα or less.  22. The information recording medium according to claim 18, wherein a part of the recording layer that is cooled so as to be solidified after being melted has a substantially circumferential minimum length of 0.5 μm or less.  23. The information recording medium according to claim 1, further comprising a protective layer in contact with the recording layer, wherein the protective layer contains at least one of oxygen and nitrogen. 24. The ratio of the nitrogen content in the protective layer to the content of all atoms in the protective layer is 1 atomic% or more and 50 atoms. The information recording medium according to claim 23, wherein the _{value is not} more than / ₀ . 25. The protective layer comprises a Z n S and S i O _2, the information recording medium according to claim 2 3. 26. The information recording medium according to claim 23, wherein said protective layer includes at least one of chromium oxide, tantalum oxide, aluminum oxide, and germanium nitride.  27. The information recording according to claim 1, wherein the oxygen concentration is a ratio of the number of oxygen atoms to the number of all atoms in a unit volume, and the oxygen concentration in the recording layer changes in the thickness direction of the recording layer. Medium.  28. The information recording according to claim 27, wherein the oxygen concentration increases from a point substantially at the center of the recording layer in the thickness direction of the recording layer toward at least one of the surfaces on both sides of the recording layer. Medium.  29. The information recording medium according to claim 27, wherein the oxygen concentration increases from a substantially central point of the recording layer toward each of the surfaces on both sides of the recording layer in a thickness direction of the recording layer. 30. In the thickness direction of the recording layer, from the point substantially at the center of the recording layer to at least one of the surfaces on both sides of the recording layer, the oxygen concentration is changed from the point substantially at the center of the recording layer. 28. The information recording medium according to claim 27, wherein the oxygen concentration increases at least twice. 31. Furthermore, a reflective layer for reflecting light is provided, and a recording layer is disposed between the reflective layer and the substrate. The recording layer has a first surface relatively closer to the substrate in the thickness direction of the recording layer and a reflective layer. 28. The information recording medium according to claim 27, further comprising a second surface that is relatively close, wherein the oxygen concentration of the first surface is lower than the oxygen concentration of the second surface.  32. The apparatus further comprises a reflective layer for reflecting light, wherein a recording layer is disposed between the reflective layer and the substrate, wherein the recording layer has a first surface relatively close to the substrate in a thickness direction of the recording layer, and a reflective layer. 28. The information recording medium according to claim 27, comprising a relatively near surface and a second surface, wherein the oxygen concentration on the first surface is higher than the oxygen concentration on the second surface.  33. A reflective layer for reflecting light is further provided. A recording layer is disposed between the reflective layer and the substrate. The recording layer has a first surface relatively close to the substrate in a thickness direction of the recording layer, and a reflective layer on the reflective layer. 28. The information according to claim 27, having a second surface that is relatively close, and wherein in a thickness direction of the recording layer, the oxygen concentration increases from a substantially central point of the recording layer toward the first surface. recoding media.  34. Furthermore, a reflective layer for reflecting light is provided, and a recording layer is disposed between the reflective layer and the substrate. The recording layer has a first surface relatively close to the substrate in a thickness direction of the recording layer and a reflective layer. 28. The information according to claim 27, further comprising a second surface that is relatively close, and in a thickness direction of the recording layer, the oxygen concentration increases from a substantially central point of the recording layer toward the second surface. recoding media. 35. The recording layer includes a first area in which information can be recorded and a second area in which only pre-recorded predetermined information is reproduced. The oxygen content of the recording layer in the first area and the second area The difference from the oxygen content of the recording layer was 18 atoms. The information recording medium according to claim 1, which is not more than / ₀ .  36. Erasure of the signal recorded in the first area and recording of the signal are performed a plurality of times, and at least a part of the recording layer in the first area is repeatedly transformed between a crystalline state and an amorphous state a plurality of times. 36. The information recording medium according to claim 35, wherein the difference between the oxygen content of the recording layer in one area and the oxygen content of the recording layer in the second area is 18 atomic% or less. 37. heating and melting a portion of the recording layer; Cooling and solidifying a part of the recording layer that is melted by heating to form a signal mark surrounded by another part of the recording layer other than a part of the recording layer, and partially crystallizing the recording layer. An information recording method is used to record a signal in the recording layer by partially transforming the recording layer by transforming between the state and the amorphous state, and the signal to be recorded is in the state of “0” and the state of “1”. One of the “0” state and the “1” state to be recorded is determined by at least a part of a boundary between a part of the recording layer and another part of the recording layer. An information recording method, wherein one of the defined and recorded "0" state and "1" state is recognized in at least a part of the boundary.  The recording layer contains oxygen as an oxide in the recording layer, and when a part of the recording layer is heated and melted, the oxide contained in the part of the recording layer causes a part of the recording layer to be melted. The viscosity is maintained to a high degree to maintain the surface tension of a part of the recording layer to a high degree, whereby the part of the recording layer that has been melted and then cooled so as to be solidified and the recording layer The information recording method, wherein at least a part of the boundary between the other part and the other part is round and smooth.  38. The information recording method according to claim 37, wherein a part of the recording layer cooled so as to be solidified after being melted is in an amorphous state, and another part of the recording layer is in a crystalline state.  39. The information recording method according to claim 37, wherein a part of the recording layer cooled so as to be solidified after being melted is in a crystalline state, and another part of the recording layer is in an amorphous state.  40. The information recording method according to claim 37, wherein a part of the recording layer is heated and melted by irradiation with a light beam.  41. The recording layer has a first recording layer and a second recording layer, and the oxygen concentration changes sharply between the first recording layer and the second recording layer, and the oxygen concentration in the thickness direction of the recording layer changes. The average oxygen concentration of one recording layer is 1/3 or less of the average oxygen concentration of the second recording layer in the thickness direction of the recording layer, and the thickness of the first recording layer is larger than the thickness of the second recording layer. Information recording media according to 27.  42. The information recording medium according to claim 41, wherein the recording layer has a plurality of second recording layers, and the first recording layer is disposed between the second recording layers.