CN1906666A - Optical recording medium, and recording and reproducing method and optical recording and reproducing apparatus of optical recording medium - Google Patents

Abstract

The present invention is aimed at providing a dual-layer phase-change optical recording medium which allows a high-density recording and a recording, where the optical recording medium has a high recording sensitivity even to a low power light with a short wavelength such as blue laser beam, does not cause noises such as jitter, has superior overwrite performance and favorable archivability, allows easier focusing and tracking and enables a compatibility with a ROM. Therefore, it provides an optical recording medium including a substrate and, on the substrate at least a first recording composite layer, an intermediate layer, a second recording composite layer and a cover substrate in this order, wherein the groove depth of the cover substrate is such that the magnitude of a push-pull signal of the first recording composite layer is equal or greater with respect to a push-pull signal of the second recording composite layer.

Description

The record regeneration method of optical recording media and optical recording media and optical recording and reproduction apparatus

Technical field

The present invention relates to the optical recording media (below the situation that is called " phase-change type optical information recording media ", " phase-change type optical recording media ", " optical information recording media ", " carrier " is arranged) of the single-sided two-layered type that the high-density recording with two-layer recording layer of rewritable DVR etc. employs and the record regeneration method and the optical recording and reproduction apparatus of this optical recording media.

Background technology

Usually, the reflectance varies that compact disk (CD) or DVD are used to from the bottom of pit and the interference of light of minute surface portion produces detects the record and the tracking signal of 2 value signals.In recent years, as the optical recording media that has regeneration interchangeability (interchangeability) with CD, except the rewritable compact disk (CD-RW:CD-Rewritable) of phase-change type is widely used gradually, DVD is also proposed the rewritable DVD of various phase-change types.In addition, having proposed at capacity is the DVD of 4.7GB, and to make the record regenerating wavelength be 350～420nm short wavelengthization and increase numerical aperture NA (Numerical Aperture) and as the scheme (referring to non-patent literature 1) of the system high-density DVR of the above capacity of 20GB.

Rewritable CD, the DVD of these phase-change types and DVR utilize by the reflection differences of the refringence generation of noncrystalline and crystalline state and phase differential variation the carrying out detection of recording information signal.Common phase-change type optical recording media has the structure that bottom protective seam, phase-change type recording layer, upper protective layer is set at least, reaches the reflection horizon on substrate; utilize the multiple interference control reflection differences and the phase differential of these structural sheets, thereby can make it have interchangeability with CD or DVD.In described CD-RW, in that refractive index is dropped in the scope of 15～25% degree, can guarantee the interchangeability of CD and tracer signal and groove signal, if use the CD driver that has added the amplification system that contains the low situation of reflectivity just can regenerate.In addition, the phase-change type optical recording media, because can only utilize the intensity modulated of a branch of focused beam wipes and recording process again, so in the phase-change type optical recording media of CD-RW or rewritable DVD etc., record also comprises (O/W) record of the overwrite (オ one バ one ラ イ ト) that writes down simultaneously and wipe.

In addition, utilize the recording of information of phase change can adopt crystallization, noncrystalline or their admixture, also can use a plurality of crystallization phases.But, the rewritable phase change type optical recording media that is practical at present, normally will not write down and erase status as crystalline state, and form amorphous mark and carry out record.

As the material of described phase-change type recording layer, be to use more and contain the sulfide-based alloy that chalcogen is S, Se or Te.For example, with GeTe-Sb ₂Te ₃Doubtful bianry alloy is the GeSbTe class of principal ingredient; With InTe-Sb ₂Te ₃Doubtful bianry alloy is the InSbTe class of principal ingredient; With Sb _0.7Te _0.3Eutectic alloy is AgInSbTe class, GeSbTe class alloy of principal ingredient etc.In these materials, mainly be at GeTe-Sb ₂Te ₃Added excessive Sb class in the doubtful bianry alloy, especially near Ge ₁Sb ₂Te ₄Perhaps Ge ₂Sb ₂Te ₅Deng the composition of intermetallic compound be practical.These are formed not follow the distinctive crystallization that is separated of intermetallic compound to turn to feature, and crystalline growth speed is fast, so initialization is easy, when wiping to recrystallize speed fast.Therefore, in the past as the recording layer that shows practical O/W characteristic, doubtful bianry alloy class or near the composition of intermetallic compound receive publicity (referring to non-patent literature 2).

In addition, formed about the GeSbTe ternary in the past or become parent with this tlv triple and contain the recording layer composition that adds element report (referring to patent documentation 1～4) was arranged.Yet the material of Zu Chenging has also just begun exploitation like this, be applicable to that also there are the problems that much must solve in the optical recording media that the high-density recording of rewritable DVR etc. is employed.

Especially under the situation of the short wavelength's of blue laser etc. optical system, light beam output is low, therefore exists recording layer to occur the such defective of noise easily.In addition; from light incident aspect; when making the thickness thickening of the protective seam between substrate and the recording layer; because when the thickness thickening of protective seam; just occur Thickness Variation easily or be difficult to realize preservation characteristics; so be difficult to satisfy this two aspect of O/W characteristic and preservation characteristics, therefore become the problem in the high-speed and high-density recordization.

In addition, under the situation of the optical recording media that can carry out the single-sided two-layered optical recording, reflectivity is following 5～7% very low of half of common optical recording media, when also considering every two-layer focusing saltus step, there is when jump to second recording layer little and focusing of push-pull signal or follows the tracks of the problem of disengaging easily.

As such single-sided two-layered optical recording media, for example, in patent documentation 5, disclose the single-sided two-layered type CD of two recording layers.In addition, but but the optical data recording medium with the first write data recording layer and second write data recording layer are disclosed in patent documentation 6.In addition, in patent document 7, disclose and had the two-layer optical-information intermediat medium that is sandwiched in the recording layer of two phase change types between the dielectric layer.

But, under the situation of described single-sided two-layered type optical recording media, need the transmitance of the recording layer (the second interrecord structure layer) of raising light incident side, and make light arrive the recording layer (the first interrecord structure layer) of an opposite side with light incident side, just can carry out record.But, when making the thickness thickening of recording layer and then making heat dissipating layer not thick in order to write down fully, exist as recording beat, modulate insufficient such problem,

Therefore present situation is, even can't obtain low output light for the short wavelength of the two-layer DVD+RW of red laser or blue laser etc., but recording sensitivity is also high, do not produce the also good and focusing of noise, O/W characteristic good, file characteristic such as beat or follow the tracks of easily, can realize and the optical recording media of the double-layer structure of the high density recording of the exchange of ROM that therefore expectation can provide as early as possible.

Patent documentation 1: the spy opens clear 61-258787 communique

Patent documentation 2: the spy opens clear 62-152786 communique

Patent documentation 3: the spy opens flat 1-63195 communique

Patent documentation 4: the spy opens flat 1-211249 communique

Patent documentation 5: the spy opens the 2003-141775 communique

Patent documentation 6: specially permit communique No. 3216794

Patent documentation 7: special table 2002-515623 communique

Non-patent literature 1:ISOM Technical Digest, ' 00 (2000), 210

Non-patent literature 2:SPIE, vol.2514 (1995), pp294-301

Summary of the invention

The objective of the invention is to, solve existing problem and tackle described demand, the record regeneration method of a kind of optical recording media and this optical recording media is provided, though this optical recording media be also high with respect to the short wavelength's of blue laser etc. low output optical recording sensitivity, do not produce beat etc. noise, O/W characteristic good, file characteristic also well, focus easily and follow the tracks of, and can with ROM exchange can high density recording the optical recording media of single-sided two-layered type.

In order to solve described problem, the inventors of the present invention result of wholwe-hearted research repeatedly draw following opinion, have substrate and on this substrate, setting gradually in the optical recording media of at least the first interrecord structure layer, middle layer, the second interrecord structure layer, by the additional groove condition, can carry out easily two-layer focusing and tracking and with the exchange of ROM.

The present invention is based on the invention of inventors' of the present invention described opinion, and the means that are used to solve described problem are as follows.That is,

＜1〉a kind of optical recording media, it is characterized in that, it has substrate and have the first interrecord structure layer, middle layer, second interrecord structure layer and the covered substrate successively at least on this substrate, and the groove depth of this covered substrate is that benchmark is that the size of the push-pull signal of the described first interrecord structure layer becomes the equal above degree of depth with the push-pull signal of the described second interrecord structure layer.This＜1〉described optical recording media in, by optical recording media additional groove condition to double-layer structure, though make also high with respect to the short wavelength's of blue laser etc. low output optical recording sensitivity, do not produce noise, O/W characteristic good, file characteristic such as beat and focus well, easily yet and follow the tracks of and can exchange with ROM.

＜2〉above-mentioned＜1〉described in optical recording media, it is under the situation of covered substrate side incident light, the groove depth (d of substrate ₁) with the groove depth (d of covered substrate ₂) satisfy following formula d ₁＞d ₂, 0＜d ₁≤ 7 λ/8n and 0＜d ₂(wherein, λ represents the record regenerating wavelength to≤7 λ/8n, and n represents the refractive index of substrate.Groove depth is except the situation of λ/4n, λ/2n and 3 λ/4n).

＜3〉above-mentioned＜1〉to＜2 in any described optical recording media, wherein, the first interrecord structure layer has reflection horizon, first contact bed, first protective seam, first recording layer and second protective seam successively from substrate-side.

＜4〉above-mentioned＜3〉described optical recording media, wherein, first recording layer contains the above Sb of 60mol% ₇₀Te ₃₀

＜5〉above-mentioned＜1〉to＜4 in any described optical recording media, wherein, the second interrecord structure layer has the 3rd protective seam, heat dissipating layer, the 4th protective seam, second recording layer and five guarantees sheath successively from the middle layer side.

＜6〉above-mentioned＜5〉described optical recording media, wherein, second recording layer contains the above Ge of 40mol% ₅₀Te ₅₀

＜7〉above-mentioned＜3〉to＜6 in any described optical recording media, wherein, first recording layer and second recording layer contain at least a element of selecting of 0.1～5 atom % from O, N and S.

＜8〉above-mentioned＜3〉to＜7 in any described optical recording media, wherein, first recording layer and second recording layer contain at least a element of selecting from V, Nb, Ta, Cr, Co, Pt and Zr.

＜9〉above-mentioned＜5〉to＜8 in any described optical recording media, wherein, between heat dissipating layer and the 4th protective seam, have the second contact surface layer.

＜10〉above-mentioned＜3〉to＜9 in any described optical recording media, wherein, first protective seam, second protective seam, the 4th protective seam and five guarantees sheath contain ZnS and SiO ₂Potpourri.

＜11〉above-mentioned＜5〉to＜10 in any described optical recording media, wherein, the 3rd protective seam contains any one among ITO and the IZO.

＜12〉above-mentioned＜3〉to＜11 in any described optical recording media, wherein, at least one contains from TiC and TiO in first contact bed and the second contact surface layer ₂Potpourri, ZrC and ZrO ₂Potpourri, SiC and SiO ₂Potpourri and CrC and CrO ₂Potpourri in select at least a.

＜13〉above-mentioned＜3〉to＜12 in any described optical recording media, wherein, reflection horizon and heat dissipating layer contain any one in Au and Au alloy, Ag and Ag alloy, Cu and the Cu alloy.

＜14〉a kind of record regeneration method of optical recording media, it is characterized in that, for above-mentioned＜1〉to＜13 in each interrecord structure layer in any described optical recording media, make light beam from the incident of described covered substrate side, carry out in recording of information and the regeneration at least one of them.

In the record regeneration method of optical recording media of the present invention, for described optical recording media of the present invention, by irradiating laser carry out recording of information and regeneration at least one of them.Its result, can stablize effectively and recording of information and regeneration reliably in any one.

＜15〉a kind of optical recording and reproduction apparatus, its to optical recording media from light source irradiation laser and this optical recording media carry out recording of information and regeneration at least one of them, it is characterized in that described optical recording media is above-mentioned＜1〉to＜13 in any described optical recording media.

Optical recorder of the present invention, to optical recording media from light source irradiation laser and this optical recording media carry out recording of information and regeneration at least one of them, use described optical recording media of the present invention as described phase-change type optical recording media.In this optical recorder of the present invention, can stablize and carry out reliably recording of information and regeneration at least one of them.

Description of drawings

Fig. 1 is the layer section of structure of an example of expression two stratotype optical recording medias of the present invention;

Fig. 2 is the sectional view of layer structure of the two stratotype optical recording medias of expression embodiment;

Fig. 3 is the groove depth and the figure that recommends the relation of (push pull) signal and RF signal of substrate of the light incident side of expression wavelength 405nm, NA=0.65;

Fig. 4 is inboard substrate is seen in expression from the light incident side of wavelength 405nm, NA=0.65 a groove depth and the figure that recommends the relation of (push pull) signal and RF signal;

Embodiment

(optical recording media)

At least the first interrecord structure layer, middle layer, second interrecord structure layer and the covered substrate that optical recording media of the present invention has substrate and forms successively on this substrate, and also have other layer as required.

The groove depth of described covered substrate is that benchmark is that the size of the push-pull signal of the described first interrecord structure layer becomes the equal above degree of depth with the push-pull signal of the described second interrecord structure layer.Thus, can carry out focusing, the tracking of second recording layer well.

Wherein, so-called described " on an equal basis ", the maximum error at measurment that is meant push-pull signal is 3% degree, little 3% the time when respectively the push-pull signal of the first interrecord structure layer and the second interrecord structure layer being read, then be 97%, big 3% the time when it is read, then be 103%, so both differences are 6% to the maximum.Therefore, when both difference of measured value is in 6%, then regard " on an equal basis " as.

Concrete, adopting under the situation of the structure of covered substrate side incident light, as the groove depth (d that makes substrate ₁) and the groove depth (d of covered substrate ₂) the pass be d ₁＞d ₂The time, from light incident side regard as into the groove depth of the substrate of inboard dark, though the push-pull signal of the first interrecord structure layer is bigger than the push-pull signal of the second interrecord structure layer thus, but owing to reduced by 40～60% by the second interrecord structure layer from the regenerated signal of the first interrecord structure layer, so can make the push-pull signal of the first interrecord structure layer approach the push-pull signal of the second interrecord structure layer, thereby focusing, tracking are stablized.And, also can make the RF signal of record become capable of regeneration level.But, since when groove depth be λ/4n, λ/2n, 3 λ/4n when (wherein, λ represents the record regenerating wavelength, and n represents the refractive index of substrate), push-pull signal becomes zero, so do not make such groove depth.In addition, the scope of groove depth is made as greater than 0 at 7 λ/below the 8n.In addition, though also can establish d ₂＞d ₁, but because easy more the obtaining of the dark more then push-pull signal of groove depth, so preferably make the big orientation of push-pull signal in the inboard.

Fig. 3 represent wavelength 405nm, NA=0.65 covered substrate groove depth with recommend (push pull) signal and RF signal.Fig. 4 represents groove depth and the push-pull signal and the RF signal of the substrate of wavelength 405nm, NA=0.65.

In the scope of Fig. 3 and groove depth shown in Figure 4, the maximal value of the push-pull signal of the second interrecord structure layer of light incident side is 23, the maximal value of seeing the push-pull signal of the first inboard interrecord structure layer from light incident side is 25, one side is big slightly for the first interrecord structure layer, and the focusing of first and second interrecord structure layer, tracking are all stablized.In addition, but the RF signal also is in the record regenerating scope equally with first and second interrecord structure layer.In addition, because preferred RF signal is big concerning regeneration, so, under the situation of Fig. 3 and Fig. 4, for example the groove depth with covered substrate is made as 30nm, and the groove depth of substrate is made as 40nm, and then first, second interrecord structure layer RF signal all becomes big, and the size of push-pull signal also about equally, so characteristic improves.

The described first interrecord structure layer of optical recording media of the present invention begins to have reflection horizon, first contact bed, first protective seam, first recording layer and second protective seam successively at least from substrate-side, and also can have other layer as required.

In addition, the described second interrecord structure layer begins to have the 3rd protective seam, heat dissipating layer, the 4th protective seam, second recording layer and five guarantees sheath successively at least from the middle layer side, and also can have other layer as required.

At this, Fig. 1 is the layer structural profile pattern illustrated figure in ground with an example of expression optical recording media of the present invention.This optical recording media has the structure of 2/ first contact bed, 14/ first protective seam, 3/ first recording layer, 4/ second protective seam, 5/ middle layer 6/, substrate 1/ reflection horizon the 3rd protective seam 7/ heat dissipating layer 8/ the 4th protective seam 9/ second recording layer 10/ five guarantees sheath 11/ covered substrate 13.And second contact surface layer (not having diagram) can be set also between heat dissipating layer 8 and the 4th protective seam 9.

-substrate-

As the material of described substrate 1, can use for example transparent resin or the clear glass of polycarbonate resin, acrylic resin, polyene resin etc.In them, polycarbonate resin is used most widely for CD, and cheap, so be most preferred material.

At the groove that is provided with usually on the described substrate 1 below the spacing 0.8 μ m of leader record reproduced light, but this groove not necessarily must be the groove of geometric rectangle or trapezoidal shape, also can form the groove of optics by utilizing the different such structures of waveguide of formation refractive index such as for example ion injection.

Under the situation of the object lens that use high NA, preferably covered substrate 13 is the thickness of the following sheet of 0.3mm, more preferably 0.06～0.20mm.As long as NA is about 0.6～0.65, then used thickness is the substrate of 0.6mm.

-the first recording layer-

As to the employed preferred phase change recording materials of first recording layer, can enumerate with Sb and Te is the alloy of principal ingredient, preferably Sb ₇₀Te ₃₀Content more than 60mol%, 60～90mol% more preferably.By making described content is more than the 60mol%, and the O/W characteristic is improved rapidly, when surpassing 90mol%, and O/W characteristic variation once more then.

In these materials, serve as the material that constitutes element preferably with Sb, Te, Ge.By such first recording layer that element constitutes that constitutes, also other element can be added to amounting to about 10 atom % as required.In addition, by on first recording layer and then add at least a element of from O, N, S, selecting of 0.1～5 atom %, can finely tune the optical constant of first recording layer.But, when adding, wipe degradation owing to making crystallization speed reduce to make above 5 atom %, be not preferred therefore.

In addition, the crystallization speed when not reducing O/W and improve aging stability is preferably added the following at least a element of selecting of 8 atom % from V, Nb, Ta, Cr, Co, Pt and Zr, and more preferably addition is 0.1～5 atom %.Be below the 15 atom % preferably for these elements of SbTe and the total addition of Ge.When surpassing 15 atom %, will cause Sb being separated of composition in addition.What particularly additive effect was big is that Ge content is the situation of 3～5 atom %.

-the second recording layer-

As at the employed preferred phase change recording materials of described second recording layer, can list with Ge and Te is the alloy of principal ingredient, preferably Ge ₅₀Te ₅₀Content more than 40mol%, 40～90mol% more preferably.By making described content is more than the 40mol%, even also become good at the high layer O/W of transmitance.In addition, when surpassing 90mol%, O/W characteristic variation.

In these materials, only the material that is made of Ge, Te is preferred.To by such second recording layer that element constitutes that constitutes, also other element can be added to amounting to about 10 atom % as required.In addition, by at recording layer and then add at least a element of from N, O, S, selecting of 0.1～5 atom %, can finely tune the optical constant of second recording layer.But, when adding, can make record, wipe the enough variation of performance above 5 atom %, be not preferred therefore.

In addition, the crystallization speed when not reducing O/W and improve aging stability is preferably added the following at least a element of selecting of 20 atom % from V, Nb, Ta, Cr, Co, Pt and Zr, and more preferably addition is 2～15 atom %.When for a long time, then cause being separated of Ge atom or Te atom than 15 atom %.

And then, as the material that adds at first and second recording layer,, preferably add the following at least a element of from Si, Sn and Pb, selecting of 5 atom % for the raising of aging stability and the fine setting of refractive index.Preferably the total addition of these elements and Ge is below the 15 atom %.In addition, Si, Sn, Pb are identical with Ge, are to have the cancellated element of 4 coordinations.

In addition,, crystallized temperature is risen, can reduce simultaneously and beat, improve recording sensitivity by adding at least a element of from Al, Ga and In, selecting below the 15 atom %, but owing to segregation also is easy to generate, so be preferably below the 10 atom %.

In addition, when adding Ag with the amount below the 8 atom %, produce effect improving on the recording sensitivity, it is remarkable that the addition that particularly ought be used for Ge surpasses under the situation of 5 atom % effect.But, when the addition of Ag surpasses 8 atom %, owing to can make the stability of beating and increasing or destroying the noncrystalline mark, so be not preferred.In addition, the total addition of Ag and Ge surpasses 15 atom % and just is easy to generate segregation, so be not preferred.Content as Ag particularly preferably is below the 5 atom %.

Preferably the thickness of first and second recording layer is the scope of 5～100nm.If just be difficult to obtain sufficient contrast than 5nm is thin, also have the slack-off tendency of crystallization speed, at short notice wipe the difficulty that easily becomes.On the other hand, if surpass the contrast that 100nm is difficult to obtain optics equally, also be easy to generate crackle.Degree need have the interchangeability with regeneration such as DVD Special disc as a comparison.

In addition, be under the situation of the high density recording below the 0.5 μ m in the shortest mark lengths, preferably the thickness of first and second recording layer is 5～25nm.Not enough 5nm then reflectivity can become low, also is prone to the influence of the uneven composition of film early growth period, sparse film, is not preferred therefore.On the other hand, if thicker than 25nm, except the big recording sensitivity variation of thermal capacitance quantitative change, because crystalline growth becomes 3 dimensions, so have the edge busyness of noncrystalline mark, the tendency of beating and increasing.And the volume change that is caused by the phase change of first and second recording layer becomes significantly, repeats overwrite (O/W) permanance variation, so be not preferred.From the beating and repeat the permanance viewpoint of overwrite (O/W) of mark end, more preferably below the 20nm.

Preferably the density of first and second recording layer is more than 80% of volume density, more preferably more than 90%.Want to make density big in the spatter film forming method, the pressure of the sputter gas in the time of will reducing film forming rare gas such as () Ar or make substrate approach the front configuration etc. of target need make the high-octane Ar amount that is radiated on the recording layer increase.

High-octane Ar is radiated at an Ar ion part on the target to be rebounded and arrive the Ar of substrate-side or the Ar ion in the plasma and quickened by the comprehensive epidermis voltage of substrate and arrive among the Ar of substrate any one for sputter.The radiation response of so high-octane rare gas is called " atom sandblast (atomic peening) effect ".Sputter in the common employed Ar gas is sneaked in the sputtered film Ar by " atom sandblast effect ".Can estimate " atom sandblast effect " according to the amount of the Ar in this film of sneaking into.That is,, mean that then the radiation response of high-energy Ar is little, easily form the sparse film of density if the amount of Ar is few.On the other hand, if the amount of Ar is too much, then the irradiation of high-octane Ar is strong, though density uprises, the Ar that enters in the film is released when repeating O/W, produces space (void), makes the repeated durability deterioration.Suitable Ar amount in the record tunic is 0.1～1.5 atom %.And,, can reduce the Ar amount in the film during use high-frequency sputtering and obtain density film, so be preferred owing to compare with d.c. sputtering.

In addition, the noncrystalline normally of the state after first and second recording layer film forming.Therefore, after the film forming, need make the comprehensive crystallization of each recording layer and as the state (not recording status) that is initialised.As initial method, also can be the initialization of being undertaken by the annealing of solid phase, still, preferably cools down makes the what is called of its crystallization be recrystallized by fusing and the initialization carried out when making the recording layer fusing for the time being and solidifying.Though the nuclear of above-mentioned each recording layer crystalline growth after film forming does not almost have, the crystallization difficulty of solid phase recrystallizes according to fusing, by melting under the situation of the nuclei of crystallization that form minority, makes crystalline growth become main body, recrystallizes to carry out at a high speed.

Because recrystallize and the crystallization that forms is different with the crystallization reflectivity that is formed by the annealing of solid phase by described fusing, so if mix the reason that just becomes noise.And, when the O/W of reality record,, the portion of wiping recrystallizes the crystallization that forms, so preferably initialization also utilizes to melt to recrystallize and carries out owing to becoming by fusing.

When utilizing fusing to recrystallize to carry out initialization, the fusing of recording layer preferably local and in 1 millisecond of short time below the degree, carry out.Its reason is, when melting range expansion, fusing time or cool time are long, because heat can make each layer destroyed or make the distortion of plasticity substrate surface.In order to give and to be suitable for initialized thermal process, preferably the high output semiconductor laser focusing about wavelength 600～1000nm being become major axis is that 100～300 μ m, minor axis are that the ellipse of 1～3 μ m shines, and scans as the linear velocity of scan axis with 1～10m/s with short-axis direction.Even if identical focused light near circle then the melting range also can be excessive, causes amorphous materialization easily again, the infringement to each layer of sandwich construction and substrate is big in addition, is not preferred.

Recrystallize by fusing for initialization and to carry out and to confirm as follows.That is, on the optical recording media after the initialization, direct current ground is focused into the recording light of the recording power Pw of littler than the 1.5 μ m approximately point enough fusing recording layers directly of diameter with certain linear velocity irradiation.Having under the situation of guiding groove, applying tracking servo and focusing is carried out under the servo condition to this groove or by the track that forms between groove.

Then, if on same rail direct current irradiation erase power Pe (≤Pw) wipe light and the reflectivity of the erase status that obtains, almost completely identical with the reflectivity of Unrecorded original state, can confirm that then this init state is to melt crystalline state again.Its reason is, because the recording light irradiation is melted recording layer for the time being, and, be to have passed through the fusing undertaken by recording light and by wiping the process that recrystallizes that light carries out and be melted the state that recrystallizes with wiping rayed itself and the state of the perfect recrystallizationization that forms.In addition, it is roughly the same that the reflectivity Rini of so-called init state and fusing recrystallize the reflectivity of state Rcry, be meant usefulness (Rini-Rcry)/(Rini+Rcry)/both reflection differences of 2} definition is (promptly below 20%) below 0.2.Usually, have only its reflection differences of solid phase crystallization of annealing etc. bigger than 20%.

-first, second, the 4th and the five guarantees sheath-

As shown in Figure 1, first recording layer is to be clipped in the state setting between first protective seam and second protective seam, and second recording layer is to be clipped in the state setting between the 4th protective seam and the five guarantees sheath.

Below at clip these recording layers first, second, the 4th and the five guarantees sheath describe.

First protective seam has the function of dispelling the heat efficiently to the reflection horizon simultaneously.In addition, second protective seam is effective to preventing that high temperature owing to when record from making the surface deformation in middle layer mainly.The 4th protective seam has simultaneously to the function of heat dissipating layer, the 3rd protective seam heat radiation and the function that prevents second recording layer and the counterdiffusion mutually of heat dissipating layer.In addition, the distortion of the covered substrate that causes of the high temperature of five guarantees sheath when preventing owing to the adjustment of reflectivity and record is effective.

First, second, the 4th and the material of five guarantees sheath, consider that refractive index, temperature conductivity, chemical stability, physical strength, connecting airtight property etc. decide.Low as material expectation thermal conduction characteristic, but its index is 1 * 10 ^-3PJ/ (μ mNnsec).In addition, the temperature conductivity of directly measuring the filminess of such low thermal conductivity material is difficult, can replace directly measuring and obtains index from the measurement result of thermal simulation and actual recording sensitivity.

As described low thermal conductivity material, can list for example ZnS, the ZnO, the TaS that contain 50～90mol% ₂, at least a transparent height and fusing point or decomposition point the composite dielectrics that comprises in the terres rares sulfide at the heat-resisting compound more than 1000 ℃.As described terres rares sulfide, can list the composite dielectrics of terres rares sulfide 60～90mol% such as containing La, Ce, Nd, Y.In these materials, especially preferably make ZnS, ZnO, TaS ₂Or the ratio of terres rares sulfide is the material of 70～90mol%.

As described fusing point or decomposition point is heat-resisting compound more than 1000 ℃, can list fluoride of oxide, nitride or the carbonide of for example Mg, Ca, Sr, Y, La, Ce, Ho, Er, Yb, Ti, Zr, Hf, V, Nb, Ta, Zn, Al, Si, Ge, Pb etc. and Ca, Mg, Li etc. etc.

And described oxide, sulfide, nitride, carbonide, fluoride not necessarily must adopt the composition of chemical dimension, for the control break of refractive index etc. form or mix use also effective.

As first, second, the 4th, and five guarantees sheath material, consider described lime light and with the matching of the material of first, second recording layer, ZnS and SiO ₂Potpourri be most preferred, consider that from manufacturing cost reduction aspect each protective seam adopts identical materials favourable.

The layer structure of optical recording media of the present invention belongs to a kind of of the layer structure that be called fast cold junction structure.Speed cold junction structure is the layer structure of the cooling velocity when promoting that by employing heat radiation raising recording layer solidifies again, in the problem that recrystallizes when avoiding the noncrystalline mark to form, has realized wiping ratio by the height of high speed crystallization generation.

The permanance of topped the writing of thickness counterweight (O/W) of the first and the 4th protective seam has a significant impact, and is especially important on variation is beated in inhibition.Thickness generally is 5～30nm.Not enough 5nm, then insufficient at the carryover effects of the heat conduction of described protective seam portion, recording sensitivity significantly descends, and is not preferred.Film Thickness Ratio 30nm is thick; then except the sufficient planarization effect of the Temperature Distribution that can not obtain the mark width direction; the recording layer side separately that also makes when record second and five guarantees sheath becomes big with the temperature difference of reflection horizon or heat dissipating layer side, owing to the thermal expansion difference of protective seam both sides causes that easily protective seam self asymmetricly is out of shape.This plastic yield that repeats to make microcosmic causes noise to increase at the protective seam inner accumulation, is not preferred therefore.

Described first and the thickness of the 4th protective seam when the wavelength of recording laser is 600～700nm, be preferably 1～25nm, when wavelength is 350～600nm, be preferably 3～20nm, more preferably 3～15nm.

In addition, described second and the thickness of five guarantees sheath, be preferably 30～150nm, consider 40～130nm more preferably from O/W characteristic aspect.Described Film Thickness Ratio 30nm is thin, and the distortion during then owing to the recording layer fusing etc. are destroyed easily, O/W characteristic variation.In addition, surpass 150nm, then the variation of reflectivity is variable big, is difficult to record equably.

When using described phase change recording materials, in the high density recording below the shortest mark lengths is 0.3 μ m, can realize low beating, but (for example at the laser diode that uses the short wavelength in order to realize high density recording, wavelength 410nm is following) situation under, also need further to note the layer structure of described fast cold junction structure.Especially use that wavelength is below the 500nm, numerical aperture NA is 1 the restrainting on overwrite (O/W) The Characteristic Study of little focused beam 0.55 or more, wipe the surplus of erase power when in order to obtain height widely, it is important making the Temperature Distribution planarization of mark width direction.Described tendency, though on the optical system of the DVR correspondence of using the optical system before and after wavelength 350～420nm, the NA=0.85 too.

Therefore, in order to have photopermeability and also to have thermal diffusivity and become high recording sensitivity,, remove second surface layer if heat dissipating layer uses Au, and the thickness that makes heat dissipating layer more than 2nm, can make the design of the sensitivity unanimity of two-layer recording layer less than 10nm.

In using the high density marker length modulated record of described optical system, use the low material of thermal conductivity at the first and the 4th protective seam especially, preferably making its thickness is that 3～20nm is important.Therefore, first contact bed that is arranged on first protective seam need be a high thermal conductivity, utilizes this structure, and heat can not discharge rapidly when high-speed record, and heat is delivered to the reflection horizon, thereby can carry out high-speed record.

In addition, the light that arrives the first interrecord structure layer owing to be see through that the second interrecord structure layer comes through light, so incident light quantity is below half of the incident light quantity of the second interrecord structure layer, therefore, expectation increases the incident light of the second interrecord structure layer or the sensitivity that improves first recording layer.

In the present invention, at the first few interrecord structure layer of incident light, the layer low with temperature conductivity clips first recording layer and improves recording sensitivity, and is that 3～20nm is easy to absorb heat by the thickness attenuate that makes first protective seam, thereby can improve recording sensitivity.

In described layer structure; under the situation of only considering thermal conductivity; can promote radiating effect though improve the coefficient of heat conductivity of first protective seam or the 4th protective seam; but promote heat radiation too much; the irradiation power that will produce record needs uprises; recording sensitivity is the such problem of decline significantly, so need limit temperature conductivity low.

And; because by using the thinfilm protective coating of low heat conductivity; in several nsec～tens of nsec (nanosecond) when recording power irradiation beginning; to giving and time delay to the heat conduction of reflection horizon or heat dissipating layer from recording layer; can promote heat radiation afterwards, so can not make the clever density of record be reduced to required above level owing to the thermal conduction characteristic of protective seam to reflection horizon or heat dissipating layer.

Because like this, known to existing with SiO ₂, Ta ₂O ₅, Al ₂O ₃, AlN, SiN etc. are the protective layer material of principal ingredient preferably do not use because the temperature conductivity of himself is too high with monomer.

-Di three protective seams-

As the 3rd protective seam preferable material, can list the ITO (In that to bring up at the light transmission rate of wavelength 380～420nm more than 70% ₂O ₃Mixing class composition with SnO), IZO (In ₂O ₃Form with the mixing of ZnO) etc.Because these material temperature conductivity height, so the heat that produces when second recording layer writes down is dispelled the heat by the 3rd protective seam via heat dissipating layer.Thus, the recording layer that is made of the phase-transition material that is principal ingredient with the rapid SbTe that cools off of needs becomes best fast cold state, thereby can form little amorphous mark.

Expectation is thick more good more if the 3rd protective seam is considered radiating effect, if but thicker than 200nm, then stress will become big and crackle occur.In addition, less than 20nm, then radiating effect is little.Therefore, preferably the thickness of the 3rd protective seam is 20～200nm, more preferably 30～160nm.

-first and second contact bed-

At satisfying layer structure of the present invention and having by 4nm thick (TiC) ₈₀(TiO ₂) ₂₀First contact bed that constitutes, the phase-change type optical recording media of second contact surface layer (structure identical) and the phase-change type optical recording media that except any one this point that does not have first, second contact bed, has identical layer of structure with embodiment 1, compared the recording sensitivity characteristic (80 ℃, the file characteristic when 85%RH preserves down) of first recording layer, the result is as shown in following table 1.

Wherein, recording is, record regenerating optical wavelength: 405nm, the NA=0.85 of object lens, line speed record: 6.0m/s, call wire density 0.160 μ m/bit, recording power: 9.0mW (minimal power of beating), regenerating power: 0.5mW is made as the 1-7 modulation with logging mode and has write down random signal.In addition, beating is σ/Tw (window width).

Table 1.

File characteristic (80 ℃, 85%RH)

	First contact bed has	First contact bed does not have	The second contact surface layer has	The second contact surface layer does not have
					Beat (%) initial stage	7.9	8.1	8.2	8.3
Beat behind (%) 300H	7.9	25.8	8.3	26.3

Know from the result of table 1, under the situation that does not have first contact bed, second contact surface layer, file characteristic variation.

In addition, when material use (TiC) as first and second contact bed ₈₀(TiO ₂) ₂₀, (ZrC) ₈₀(ZrO ₂) ₂₀, (SiC) ₈₀(SiO ₂) ₂₀, (CrC) ₈₀(CrO ₂) ₂₀In any one the time because these these material settling outs, and the oxygen amount in the material is following a small amount of of 10 weight %, so even in the reflection horizon or heat dissipating layer use Ag or Al etc. also almost to can't see the variation that oxidation causes.The file keeping quality of the optical recording media of the reflection horizon that constitutes with above-mentioned material with by Ag and heat dissipating layer combination (preserving 200 hours under 80 ℃, 85%RH) is verified, the result, the no change of beating of the mark of record has shown good characteristic.

Form 2～15nm by thickness unfertile land, be preferably about 3～10nm, can be easy to dispel the heat to the reflection horizon with first and second contact bed.Contain S and the reflection horizon comprises under the situation of Ag at protective seam, because Ag cures easily, so, need 2nm at least in order to suppress its reaction.In addition, if blocked up,, can't write down tick marks, so under blue wavelength, be preferably below the 15nm because thermal capacitance is easily accumulated.

But; the thermal diffusivity of the second interrecord structure layer; like that just the thermal diffusivity of the 3rd protective seam is inadequate as described; in the recording layer that constitutes by phase-transition material; owing to utilizing the initial fast cold amorphous mark that forms; so, utilize the structure of the 3rd protective seam and heat dissipating layer combination can be improved high density recording characteristic, O/W characteristic, keeping quality in order to improve thermal diffusivity.

-reflection horizon-

Use the especially high material of temperature conductivity by the reflection horizon, can improve and wipe erase power surplus when.Found that of research, want the good erasing characteristic that performance recording layer of the present invention is held in wide erase power scope, use preferably just that the Temperature Distribution of film thickness direction and time change, and the also layer structure of planarization as much as possible of the Temperature Distribution of face direction (direction that relative record beam flying direction is vertical).Therefore, in the present invention, preferably use very high temperature conductivity, the following thin reflection horizon of 300nm to promote horizontal radiating effect.

In addition, the temperature conductivity of film is compared less with the temperature conductivity of body state usually.Especially the film of the not enough 40nm of thickness because the influence of the island structure of early growth period has temperature conductivity to reduce the above situation of 1 figure place, is not preferred.And because according to membrance casting condition and crystallinity or impurity level difference, so even plan to make the film temperature conductivity of same composition difference is arranged also, this is to need to consider.

Though make the heat radiation in thickness thickening also can the promotion reflection horizon of the first interrecord structure layer in reflection horizon, but when thickness surpasses 300nm, compared with the face direction of first recording layer, the heat conduction of film thickness direction becomes significantly, can not reach the effect of the Temperature Distribution of improving the face direction.In addition, the thermal capacity in reflection horizon self increases, and not only reflection horizon, and the cooling of first recording layer also needs the time, has hindered the formation of noncrystalline mark.The reflection horizon of thin high thermal conductivity most preferably is set and promotes selectively to horizontal heat radiation.The existing fast cold junction structure that is used, the heat of only paying attention to 1 dimension of film thickness direction discharges, and only expectation to the reflection horizon quick heat radiating, but does not give one's full attention to the planarization of the Temperature Distribution of this in-plane from first recording layer.

As the material in described reflection horizon, can list Au and Au alloy, Ag and Ag alloy, Cu and Cu alloy, Al and Al alloy etc.As the Ag alloy, preferably contain more than the Ag90 atom %.Can list Cu, Pt, Pd etc. as adding element.

Using under Ag or the situation of Ag alloy as the reflection horizon, preferred thickness is 30～200nm.If not enough 30nm is even its radiating effect of pure Ag is also insufficient.When surpassing 200nm, discharge to vertical direction compared with horizontal direction heat, the heat distribution that is unprofitable to horizontal direction improves, and unwanted thick film can make productivity descend.In addition, also variation of the flatness of the microcosmic on film surface.

As the Al alloy, can list the alloy that has added at least a element 0.2～2 atom % that from for example Ta, Ti, Co, Cr, Si, Sc, Hf, Pd, Pt, Mg, Zr, Mo and Mn, selects, these alloy specific insulations increase pro rata with the concentration of adding element, in addition, owing to improved anti-projection, use so can consider that permanance, specific insulation, film forming speed wait.When adding amount of element less than 0.2 atom %, though also form according to membrance casting condition, the inadequate situation of anti-projection (ロ of anti-ヒ Star Network) is many.In addition, if more, then be difficult to obtain described low-resistivity than 2 atom %.Under the situation of more paying attention to aging stability, preferably with Ta as adding element.

And the Al-Cu class alloy that contains Cu0.3～5.0 atom % also is preferred.Especially at stacked ZnS and SiO ₂Mixing the class film and the Ta that form ₂O ₅Under the situation of the protective seam of the double-layer structure of film, satisfy the complete characteristic of corrosion stability, connecting airtight property, high thermal conductivity well owing to contain the Al-Cu class alloy equilibrium of Cu0.5～4.0 atom %, so be preferred.In addition, the Al-Mg-Si class alloy that contain Si0.3～0.8 atom %, contains Mg0.3～1.2 atom % also is preferred.

State in the use under the situation of Al alloy as the reflection horizon, preferred thickness is 150～300nm.Not enough 150nm, even then pure Al radiating effect is also insufficient, if surpass 300nm, then the situation with the Ag alloy is identical, discharge to vertical direction compared with horizontal direction heat, be unprofitable to the improvement of the heat distribution of horizontal direction because the thermal capacitance quantitative change in reflection horizon self is big, so that the cooling velocity of recording layer is slack-off.In addition, the flatness variation of the microcosmic on film surface.

Having confirmed increases pro rata at the Ag alloy of reflection horizon use or the concentration of its specific insulation of Al alloy and its interpolation element.On the other hand, the interpolation of impurity reduces the crystallization particle diameter usually, makes the electronics increase at random of crystal boundary, and temperature conductivity is descended.Add the adjusting of the amount of impurity, need for obtaining the original high thermal conductivity of material by increase crystallization particle diameter.

Crystalline growth during near second recording layer of the present invention solidifying again crystallized temperature (Tm) becomes the speed that recrystallizes.Make near the cooling velocity of Tm increase to the limit, reliably and clearly form noncrystalline mark and edge thereof, hypervelocity cold junction structure is effective, and, the planarization of the Temperature Distribution of face direction can be wiped at a high speed near Tm originally, thereby can guarantee reliably by recrystallizing wiping of carrying out up to higher erase power.Therefore; when being applied on the second interrecord structure layer of the present invention with so-called " having considered the hypervelocity cold junction structure of the heat conduction carryover effects of the 3rd protective seam "; even use the structure of translucent phase-transition material, also can noncrystallineization form record mark well.

-heat dissipating layer-

In the present invention, heat dissipating layer is set for such hypervelocity is cold.When heat dissipating layer formed, the rate of sedimentation in the time of need making film forming was eliminated membrane thickness unevenness slowly than the situation in reflection horizon.Preferably its thickness is more than 2nm and less than 10nm, if less than 2nm, even then rate of sedimentation slow down also can form inhomogeneous.If be not less than 10nm, then the transmitance owing to the second interrecord structure layer can not increase, so light can not arrive first recording layer.Preferably the transmitance of the second interrecord structure layer is more than 40%.

As the material of heat dissipating layer, in order to form above-mentioned hypervelocity cold junction structure, preferred Au and Au alloy, Ag and Ag alloy, Cu and Cu alloy.

Au is about 37% at the reflectivity of thickness 200nm, than the reflectivity of thickness 200nm is that 88% Ag is low, but since absorb identical with Ag, so during more than the 2nm of thin thickness and less than the thickness of 10nm, transmitance is uprised, can be used as the semitransparent layer of the second interrecord structure layer.

To Ag or Ag alloy, identical with the situation in described reflection horizon, preferred thickness is also owing to identical reason is 30～200nm.

State in the use under the situation of Al alloy as the reflection horizon, preferred thickness is 150～300nm.If less than 150nm, even then pure Al radiating effect is also insufficient.In addition,, then discharge to vertical direction, be unprofitable to the improvement of the heat distribution of horizontal direction, the thermal capacity of reflection heat dissipating layer self is increased, therefore make the cooling velocity of recording layer slack-off compared with horizontal direction heat if surpass 300nm.In addition, also variation of the flatness of the microcosmic on film surface.

Under the situation of using Cu or Cu alloy, by eliminate sulphur (S) and oxygen (O) at adjoining course as far as possible as heat dissipating layer, under red wavelength during more than the 2nm of thin thickness and less than the thickness of 10nm, transmitance is uprised, because metal also is the high material of temperature conductivity, so preferably as the semitransparent layer of the second interrecord structure layer.

Described reflection horizon and heat dissipating layer form with sputtering method or vacuum vapour deposition usually, but the moisture of sneaking into need make the impurity level that merged target, deposition material itself and film forming time the and all impurity levels of oxygen amount are below the 2 atom %.Therefore, preferably making the vacuum tightness that reaches of process chamber is 1 * 10 ^-3Below the Pa.In addition, when with than 10 ^-4During the reaching vacuum tightness and carry out film forming of difference, making rate of film build is 1nm/ more than second, and it is above to prevent that impurity from entering second to be preferably 10nm/.Perhaps, under the situation that contains the element that adds intentionally of Duoing than 1 atom %, preferably making rate of film build is that 10nm/ prevents sneaking into of additional impurities with doing one's utmost more than second.

The situation that also exists membrance casting condition and impurity level irrespectively the crystallization particle diameter to be exerted an influence.For example, in Al, sneaked into the alloy film of the Ta about 2 atom %, the amorphous phase that between crystal grain, mixes, but the ratio of crystallization phase and amorphous phase depends on membrance casting condition.In addition, the ratio of the crystalline portion of sputter under low pressure increases, and specific insulation descends, and temperature conductivity increases.

The composition of impurity or crystallinity also depend on the method for making or the sputter gas (Ar, Ne, Xe etc.) of the employed alloys target of sputter in the film.Like this, the specific insulation of filminess is only by determining forming of metal material.Obtain high thermal conductivity and reduce impurity level as described above though be preferably, on the other hand, because the simple metal of Ag or Al has the tendency of corrosion stability or anti-projection difference, so need to consider both best compositions of balance decision.

It also is effective making the reflection horizon multiple stratification in order to obtain higher thermal conductivity and high reliability.In this case; at least 1 layer constitutes as follows; both; it has the thickness more than 50% of all layers total film thickness; and constitute in the described high conductivity material of radiating effect (low volume resistivity material), thereby help the corrosion stability, connecting airtight property, the improvement of anti-projection of other layer with protective seam by practical function.

As object lesson, in using metal under the situation of the Ag of high thermal conductivity and low specific insulation, when with the protective seam of Ag adjacency in when comprising S, easily cause the sulfuration of Ag and the corrosion that causes, have the slightly fast tendency of deterioration of repetition overwrite (O/W) situation.

Therefore, when using Ag or Ag alloy as low volume resistivity material, and the adjacency protective seam between as contact bed thickness to be set be that the Al alloy-layer of 1～100nm is also effective.Can use and the identical materials illustrated as the Al alloy the reflection horizon.If the thickness of contact bed less than 1nm, then protects effect insufficient,, then can sacrifice radiating effect if surpass 100nm.In addition, be more than the 5nm if make thickness, then layer can not become island structure and be formed uniformly easily.

And when using Ag alloy heat dissipating layer and Al alloy interface layer, because Ag and Al are than the combination that is easier to mutual diffusion, institute is so that the thickness more than the Al alloy surface oxidation 1nm and interface oxide layer is set is preferred.In addition, when the thickness of interface oxide layer surpasses 5nm, when especially surpassing 10nm, it becomes thermal resistance, has destroyed the original function as the high heat dissipating layer of thermal diffusivity, so be not preferred.

In the present invention, for the reflection horizon and the heat dissipating layer of the high thermal conductivity of selecting to show superperformance, also can directly measure temperature conductivity separately, but can utilize resistance to estimate the quality of heat conduction.Reason is in the main material that is come heat conduction or conduction by electronics as metal film, and the good proportion relation is arranged between temperature conductivity and the conductance.

The resistance of film is used in its thickness and measures on the area in territory normalized resistivity value and represent.Specific insulation and surface resistivity can enough common four probe methods be measured, and are stipulated by JIS N7194.According to this method, much easier than the temperature conductivity of actual measurement film itself, and can access the good data of repeatability.

As the characteristic of preferred reflection horizon and heat dissipating layer, preferred volume resistivity is 20～150n Ω m, more preferably 20～100n Ω m.In filminess, in fact difficulty is less than 20n Ω m.In addition, though at specific insulation than the big situation of 150n Ω m, the thick film that for example surpasses 300nm also can reduce surface resistivity, can not obtain sufficient radiating effect but only reduce surface resistivity in high like this volume resistivity material.The thermal capacity that can consider the thick film per unit area can increase.In addition, such thick film is because film forming needs the time fee of material also to increase, thus be not only from the viewpoint of manufacturing cost not preferred, and also variation of the microscopic flatness on film surface.

The multiple stratification of described reflection horizon and heat dissipating layer is for also being effective by using desired thickness to obtain desired surface resistivity the combination of high volume resistivity material and low volume resistivity material.Though utilize the adjusting of the specific insulation that alloying carries out, can simplify sputtering process owing to use alloys target, the starting material that also become the manufacturing cost that makes target and make medium are than the main cause that rises.Therefore, make the thin-film multilayerization of film and the above-mentioned interpolation element itself of pure Al, pure Ag or pure Au, it also is effective obtaining desired specific insulation.If about the number of plies to 3 layer, though the installation cost at initial stage increase, otherwise can suppress the medium cost.Preferably making the reflection horizon is to be the sandwich construction of 40～300nm by the film formed total film thickness of multiple layer metal, total film thickness be the metal film layer (can be multilayer) of 20～150n Ω m for specific insulation more than 50%.

Below, as shown in Figure 1, in the structure that thin covered substrate is set, under the situation of the object lens that use high NA, the thickness of preferred covered substrate is below the 0.3mm, more preferably 0.06～0.20mm.NA is 0.50～0.70, and used thickness is the covered substrate of 0.6mm.

Material as described covered substrate, can list polycarbonate resin, acrylic resin, epoxy resin, polystyrene resin, acrylonitritrile-styrene resin, polyvinyl resin, acrylic resin, polysiloxane resinoid, fluorine-type resin, ABS resin, urethane resin etc., but preferred polycarbonate resin, acrylic resin good aspect optical characteristics, cost.

As using the slide that constitutes by these materials to form the method for slim covered substrate, can list the method for pasting slide by ultraviolet curable resin or transparent double-sided adhesive sheet.In addition, also can on protective seam, apply ultraviolet curable resin and make it be solidified to form slim covered substrate.

Though on middle layer or adhesive linkage, also can use above-mentioned resin, because ultraviolet curable resin is good aspect cost, so be preferred.

The thickness in middle layer about NA is 0.6～0.65, under the situation of blue (405nm) LD, is preferably 20～50 μ m that can reduce from the interference of the signal of each layer, more preferably 30～40 μ m.

Can provide following optical recording media according to the present invention, even it is the low output light with respect to short wavelengths such as blue lasers, recording sensitivity is also high, do not produce beat etc. noise, O/W characteristic good, file characteristic also well, focus easily and follow the tracks of, can exchange and the optical recording media of phase-change type that can high density recording with ROM.

(record regeneration method of optical recording media)

The record regeneration method of optical recording media of the present invention, it carries out recording of information and regeneration for each Information Level of the optical recording media of described double-layer structure of the present invention from covered substrate side incident beam.

Specifically, Yi Bian make linear velocity or the fixed angular speed of the regulation rotation of optical recording media with regulation, Yi Bian shine the recording light of semiconductor laser (for example oscillation wavelength of wavelength 350～700nm) etc. by object lens from the covered substrate side.Utilize this irradiates light, make first and second recording layer absorb this light and local temperature rises, for example form the noncrystalline mark and recorded information.The regeneration of the information that is recorded as described above is while can be undertaken by making optical recording media rotate from the substrate-side irradiating laser and detect its reflected light with the alignment speed of regulation.

(optical recording and reproduction apparatus)

Optical recording and reproduction apparatus of the present invention, its to optical recording media from light source irradiation laser, at least a in enterprising line item of this optical recording media and regenerating information, and use described optical recording media of the present invention as described optical recording media.

Described optical recording and reproduction apparatus is not particularly limited, can suitably select according to purpose, for example, have condenser lens on the optical recording media that is installed in the rotating shaft of the LASER Light Source as light source of the semiconductor laser that penetrates laser etc., the laser focusing that will penetrate from LASER Light Source, the laser guide condenser lens that will penetrate from LASER Light Source and the optical element of laser detector, the catoptrical laser detector of detection laser, and then also can have other mechanism as required.

Described optical recording and reproduction apparatus will utilize optical element guiding condenser lens from the laser that LASER Light Source penetrates, and laser focusing will be radiated on the optical recording media and at the enterprising line item of optical recording media by this condenser lens.At this moment, optical recording and reproduction apparatus is the guides reflected light laser detector of laser, and controls the light quantity of LASER Light Source according to the detection limit of the laser of laser detector.

Described laser detector is transformed into voltage or electric current with the detection limit of detected laser and exports as the detection limit signal.

As described other mechanism, can list control gear etc.Be not limited to control the action of described each mechanism as described control gear, there is no particular limitation, can suitably select according to purpose, for example can list the equipment of the sequencer (シ one ケ Application サ one) that is used to shine and scan the laser that carries out intensity modulated, computing machine etc.

Below utilize embodiment to explain the present invention, but the present invention is not subjected to any qualification of following embodiment.

(embodiment 1)

The making of-optical recording media-

On polycarbonate resin substrate 21, form reflection horizon 22 (Ag successively ₉₇Cu ₁Pt ₁Pd ₁), the first contact bed 34[(TiC) ₈₀(TiO ₂) ₂₀], first protective seam, 23 (ZnSSiO ₂), first recording layer, 24 (Ag ₅In ₅Sb ₆₅Te ₂₅), second protective seam, 25 (ZnSSiO ₂), middle layer 26 (UV cured resin, the マ テ リ ア of Mitsubishi Le Zhu formula Hui She System, SD318), the 3rd protective seam 27 (IZO), heat dissipating layer 28 (Ag ₉₇Cu ₁Pt ₁Pd ₁), second contact surface layer 35[(TiC) ₈₀(TiO ₂) ₂₀], the 4th protective seam 29 (ZnSSiO ₂), second recording layer, 30 (Ge ₄₃Te ₄₃Sn ₁₂N ₂), five guarantees sheath 31 (ZnSSiO ₂) and covered substrate 33 (polycarbonate resin), make the optical recording media of layer structure shown in Figure 2.

In addition, the thickness of each layer such as following, middle layer 26 usefulness spin-coating methods form, and covered substrate 33 is pasted by transparent bonding sheet (the thick POLYCARBONATE SHEET (Port リ カ シ one ト) of the Supreme Being people's strain formula meeting System of society 75 μ m), and other layer utilizes sputtering method limit control thickness edges to form.

The thickness of substrate 21: 0.6mm; the thickness in reflection horizon 22: 100nm; the thickness of first contact bed 34: 2nm; the thickness 10nm of first protective seam 23; the thickness of first recording layer 24: 14nm; the thickness of second protective seam 25: 60nm; the thickness in middle layer 26: 35 μ m; the thickness of the 3rd protective seam 27: 30nm; the thickness of heat dissipating layer 28: 5nm, the thickness of the 4th protective seam 29: 8nm, the thickness of second recording layer 30: 12nm; the thickness of five guarantees sheath 31: 130nm, the thickness of covered substrate 33: 0.6mm.In addition, the groove depth d of substrate 1 ₁=35nm, the groove depth d of covered substrate ₂=30nm.

(embodiment 2)

The making of-optical recording media-

In embodiment 1, except the material of first contact bed is changed into (ZrC) ₈₀(ZrO ₂) ₂₀, the material of the 3rd protective seam is changed into ITO, removed the second contact surface layer and heat dissipating layer has been changed into outside the Au of thickness 5nm, identical with embodiment 1, made optical recording media.

(embodiment 3)

The making of-optical recording media-

In embodiment 1, except first contact bed is changed into (SiC) ₈₀(SiO ₂) ₂₀, the material of second contact surface layer is changed into (CrC) ₈₀(CrO ₂) ₂₀, the groove depth of substrate and covered substrate is changed into d ₁=75nm, d ₂Outside=the 90nm, identical with embodiment 1, made optical recording media.

(embodiment 4)

The making of-optical recording media-

In embodiment 1, except the material of first contact bed, second contact surface layer is changed into (SiC) ₈₀(SiO ₂) ₂₀, the groove depth of substrate and covered substrate is changed into d ₁=160nm, d ₂Outside=the 150nm, identical with embodiment 1, made optical recording media.

(embodiment 5)

The making of-optical recording media-

In embodiment 1, except the groove depth of substrate and covered substrate is changed into d ₁=230nm, d ₂Outside=the 220nm, identical with embodiment 1, made optical recording media.

(embodiment 6)

The making of-optical recording media-

In embodiment 1, identical with embodiment 1 except first contact bed is not set, made optical recording media.

(embodiment 7)

The making of-optical recording media-

In embodiment 1, identical with embodiment 1 except the second contact surface layer is not set, made optical recording media.

(embodiment 8)

The making of-optical recording media-

In embodiment 1, except the groove depth of substrate and covered substrate is changed into d ₁=100nm, d ₂Outside=the 35nm, identical with embodiment 1, made optical recording media.

(comparative example 1)

The making of-optical recording media-

In embodiment 1,, the groove depth of substrate and covered substrate is changed into d except removing first contact bed ₁=60nm, d ₂Outside=the 50nm, identical with embodiment 1, made optical recording media.

(comparative example 2)

The making of-optical recording media-

In embodiment 1, except the groove depth of substrate and covered substrate is changed into d ₁=100nm, d ₂Outside=the 40nm, identical with embodiment 1, made optical recording media.

(reference example 1)

The making of-optical recording media-

In embodiment 1, identical with embodiment 1 except the 3rd protective seam and first and second contact bed are not set, made optical recording media.

For each optical recording media of resulting embodiment 1～8 and comparative example 1～2, reference example 1, table 2 has been represented the groove depth of the first interrecord structure layer and the second interrecord structure layer and the ratio of push-pull signal (signal magnitude of the second interrecord structure layer being made as the signal magnitude of 1 o'clock the first interrecord structure layer).

In addition, the wavelength of optical system is made as 402nm.In addition, the refractive index n of polycarbonate resin is about 1.53.

Table 2.

	The first interrecord structure layer		The second interrecord structure layer
					d 1Groove depth (nm)	Push-pull signal	d 2Groove depth (nm)	Push-pull signal
	Embodiment 1	35	1.2	30					1
Embodiment 2					35	1.2	30	1
	Embodiment 3	75	4.4	90					1
Embodiment 4					160	1.5	150	1
	Embodiment 5	230	1.3	220					1
Embodiment 6					35	1.2	30	1
	Embodiment 7	35	1.2	30					1
Embodiment 8					100	1.0	35	1
	Comparative example 1	60	0.25	50					1
Reference example 1					35	1.2	30	1
	Comparative example 2	100	0.8	40					1

According to the result of table 2, the groove depth of the first interrecord structure layer of comparative example 1 is 60nm, but since this value near λ/(4n)=402nm/4 * 1.53 ≈ 66nm, so the push-pull signal of the second interrecord structure layer diminishes, becoming is difficult to follow the tracks of.

In addition, the second interrecord structure layer since second recording layer have under the situation of record and under the unwritten situation transmitance all change, so, just be difficult to stablize if the size of the push-pull signal of the first interrecord structure layer is not to be equal to or greater than the second interrecord structure layer.On the contrary, when the push-pull signal of the first interrecord structure layer hour, make to follow the tracks of to become unstable, it is unstable that two-layer record becomes easily.

The constituent material of each layer of each optical recording media of table 3-1,3-2 concentrated expression embodiment 1～8 and comparative example 1～2, reference example 1.

Table 3-1.

	Substrate 21	Reflection horizon 22	First contact bed 34	First, second, the 4th, five guarantees sheath (*)	First recording layer 24	Middle layer 26
							Embodiment 1	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(TiC) 80(TiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	UV resin (SD318)
Embodiment 2	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(ZrC) 80(ZrO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
							Embodiment 3	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(SiC) 80(SiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
Embodiment 4	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(SiC) 80(SiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
							Embodiment 5	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(TiC) 80(TiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
Embodiment 6	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	Do not have	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
							Embodiment 7	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(TiC) 80(TiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
Embodiment 8	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(TiC) 80(TiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
							Comparative example 1	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	Do not have	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
Reference example 1	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	Do not have	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin
							Comparative example 2	Polycarbonate	Ag 97Cu 1Pt 1Pd 1	(TiC) 80(TiO 2) 20	ZnSSiO 2	Ag 5In 5Sb 65Te 25	The UV resin

Table 3-2.

	Heat dissipating layer 28	The 3rd protective seam 27	Second recording layer 30	Groove depth (d 1/d 2) ：nm	Covered substrate 33	Second contact surface layer 35
							Embodiment 1	Ag 97Cu 1Pt 1Pd 1	IZO (In 2O 3And ZnO)	Ge 43Te 43Sn 12N 2	35/30	Polycarbonate	(TiC) 80(TiO 2) 20
Embodiment 2	Au	IZO (In 2O 3And ZnO)	Ge 43Te 43Sn 12N 2	35/30	Polycarbonate	Do not have
							Embodiment 3	Ag 97Cu 1Pt 1Pd 1	IZO	Ge 43Te 43Sn 12N 2	75/90	Polycarbonate	(CrC) 80(CrO 2) 20
Embodiment 4	Ag 97Cu 1Pt 1Pd 1	IZO	Ge 43Te 43Sn 12N 2	160/150	Polycarbonate	(SiC) 80(SiO 2) 20
							Embodiment 5	Ag 97Cu 1Pt 1Pd 1	IZO	Ge 43Te 43Sn 12N 2	230/220	Polycarbonate	(TiC) 80(TiO 2) 20
Embodiment 6	Ag 97Cu 1Pt 1Pd 1	IZO	Ge 43Te 43Sn 12N 2	35/30	Polycarbonate	(TiC) 80(TiO 2) 20
							Embodiment 7	Ag 97Cu 1Pt 1Pd 1	IZO	Ge 43Te 43Sn 12N 2	35/30	Polycarbonate	Do not have
Embodiment 8	Ag 97Cu 1Pt 1Pd 1	IZO (In 2O 3And ZnO)	Ge 43Te 43Sn 12N 2	100/35	Polycarbonate	(TiC) 80(TiO 2) 20
							Comparative example 1	Ag 97Cu 1Pt 1Pd 1	IZO	Ge 43Te 43Sn 12N 2	50/60	Polycarbonate	(TiC) 80(TiO 2) 20
Reference example 1	Ag 97Cu 1Pt 1Pd 1	Do not have	Ge 43Te 43Sn 12N 2	35/30	Polycarbonate	Do not have
							Comparative example 2	Ag 97Cu 1Pt 1Pd 1	IZO (In 2O 3And ZnO)	Ge 43Te 43Sn 12N 2	100/40	Polycarbonate	(TiC) 80(TiO 2) 20

(*) the first: the first protective seam 23, the second: second protective seam 25, the four: the four protective seam 29, the five: the five guarantees sheath 31

(evaluation)

Each optical recording media for the foregoing description 1～8 and comparative example 1～2, reference example 1, use the irradiation optical system focused beam of wavelength 402nm, numerical aperture NA0.65, under the condition of on-line velocity: 6.0m/s, 0.160 μ m/bit, with following benchmark evaluation initially beat (Jitter), recording sensitivity (recording power, i.e. the expression minimal power of beating), file characteristic and O/W characteristic.The result is illustrated among 4-1, the 4-2.

(metewand of file characteristic)

Under the preservation state of 80 ℃, 85% (RH), beat the time (H) more than 20% of rising to.

(metewand of O/W characteristic)

Because the rising of beating that overwrite (O/W) causes reaches 20% overwrite number of times (inferior).

(metewand of recording sensitivity (recording power))

The minimal power of beating

Table 4-1.

The first interrecord structure layer

Example	Recording sensitivity (mW)	Initial Jitter (%)	File characteristic (H)	O/W characteristic (inferior)	Transmitance (%)
						Embodiment 1	7.5	6.8	2000	10000	48
Embodiment 2	8	7.1	1500	10000	49
						Embodiment 3	8.5	6.9	2000	10000	48
Embodiment 4	8	7.3	2000	20000	50
						Embodiment 5	8.5	7.2	2000	10000	48
Embodiment 6	8	7.1	2000	10000	49
						Embodiment 7	8.5	7.2	2000	10000	48
Embodiment 8	8.0	6.9	2000	10000	51
						Comparative example 1	9.5	7.2	150	1000	34
Reference example 1	10	7.2	300	1000	38
						Comparative example 2	8.5	7.1	2000	10000	42

Table 4-2.

The second interrecord structure layer

	Recording sensitivity (mW)	Initial Jitter (%)	File characteristic (H)	O/W characteristic (inferior)
					Embodiment 1	9.5	6.8	2000	10000
Embodiment 2	9.5	7.1	1500	10000
					Embodiment 3	10	6.9	2000	10000
Embodiment 4	9.5	7.3	2000	20000
					Embodiment 5	10	7.2	2000	10000
Embodiment 6	9.5	7.3	2000	10000
					Embodiment 7	10	7.2	2000	10000
Embodiment 8	8.5	6.9	2000	10000
					Comparative example 1	*	*	*	*
Reference example 1	*	*	*	*
					Comparative example 2	10.5	9.1	2000	10000

(*) because the focusing failure can't record

From the table 4-1,4-2 the result as can be seen, the optical recording media of embodiment 1～8 is compared with comparative example 1, demonstrates good recording sensitivity, file characteristic, O/W characteristic.

Relative therewith, the non-constant of the preservation characteristics of comparative example 1 (file characteristic), recording power is also high, and sensitivity is bad.In addition, the recording sensitivity of comparative example 2 and initially beat poor.

The possibility of utilizing on the industry.

Optical recording media of the present invention can be widely used in such as Blu-ray Disk (Blu-ray disc) system of CD-RW, DVD+RW, DVD-RW, DVD-RAM, use blue-violet laser etc.

Claims (15)

1, a kind of optical recording media, it is characterized in that, it has substrate and have the first interrecord structure layer, middle layer, second interrecord structure layer and the covered substrate successively at least on this substrate, and the groove depth of described covered substrate is that benchmark is that the size of the push-pull signal of the described first interrecord structure layer becomes the equal above degree of depth with the push-pull signal of the described second interrecord structure layer.

2, optical recording media as claimed in claim 1 is characterized in that, under the situation of covered substrate side incident light, and the groove depth (d of substrate ₁) with the groove depth (d of covered substrate ₂) satisfy following formula d ₁＞d ₂, 0＜d ₁≤ 7 λ/8n and 0＜d ₂≤ 7 λ/8n (wherein, λ represents the record regenerating wavelength, and n represents the refractive index of substrate, and groove depth is except the situation of λ/4n, λ/2n and 3 λ/4n).

3, as any described optical recording media in claim 1 or 2, it is characterized in that the first interrecord structure layer has reflection horizon, first contact bed, first protective seam, first recording layer and second protective seam successively from substrate-side.

4, optical recording media as claimed in claim 3 is characterized in that, first recording layer contains the above Sb of 60mol% ₇₀Te ₃₀

5, as any described optical recording media in the claim 1 to 4, it is characterized in that the second interrecord structure layer has the 3rd protective seam, heat dissipating layer, the 4th protective seam, second recording layer and five guarantees sheath successively from the middle layer side.

6, optical recording media as claimed in claim 5 is characterized in that, second recording layer contains the above Ge of 40mol% ₅₀Te ₅₀

As any described optical recording media in the claim 3 to 6, it is characterized in that 7, first recording layer and second recording layer contain at least a element of selecting of 0.1～5 atom % from O, N and S.

8, as any described optical recording media in the claim 3 to 7, it is characterized in that first recording layer and second recording layer contain at least a element of selecting from V, Nb, Ta, Cr, Co, Pt and Zr.

9, as any described optical recording media in the claim 5 to 8, it is characterized in that between heat dissipating layer and the 4th protective seam, having the second contact surface layer.

10, as any described optical recording media in the claim 3 to 9, it is characterized in that first protective seam, second protective seam, the 4th protective seam and five guarantees sheath contain ZnS and SiO ₂Potpourri.

11, as any described optical recording media in the claim 5 to 10, it is characterized in that the 3rd protective seam contains any one among ITO and the IZO.

12, as any described optical recording media in the claim 3 to 11, it is characterized in that at least one contains from TiC and TiO in first contact bed and the second contact surface layer ₂Potpourri, ZrC and ZrO ₂Potpourri, SiC and SiO ₂Potpourri and CrC and CrO ₂Potpourri in select at least a.

As any described optical recording media in the claim 3 to 12, it is characterized in that 13, reflection horizon and heat dissipating layer contain any one in Au and Au alloy, Ag and Ag alloy, Cu and the Cu alloy.

14, a kind of record regeneration method of optical recording media, it is characterized in that, for each the interrecord structure layer in any described optical recording media in the claim 1 to 13, make light beam from the incident of described covered substrate side, carry out recording of information and regeneration at least one of them.

15, a kind of optical recording and reproduction apparatus, its to optical recording media from light source irradiation laser and this optical recording media carry out recording of information and regeneration at least one of them, it is characterized in that described optical recording media is any described optical recording media in the claim 1 to 13.

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