Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
  • C23C14/34—Sputtering
  • C23C14/3407—Cathode assembly for sputtering apparatus, e.g. Target
  • C23C14/3414—Metallurgical or chemical aspects of target preparation, e.g. casting, powder metallurgy
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
  • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
  • G11B7/241—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material
  • G11B7/242—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers
  • G11B7/243—Record carriers characterised by shape, structure or physical properties, or by the selection of the material characterised by the selection of the material of recording layers comprising inorganic materials only, e.g. ablative layers
  • G11B7/2433—Metals or elements of Groups 13, 14, 15 or 16 of the Periodic Table, e.g. B, Si, Ge, As, Sb, Bi, Se or Te
• • G—PHYSICS
  • G11—INFORMATION STORAGE
  • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
  • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
  • G11B7/24—Record carriers characterised by shape, structure or physical properties, or by the selection of the material
  • G11B7/26—Apparatus or processes specially adapted for the manufacture of record carriers
  • G11B7/266—Sputtering or spin-coating layers

Definitions

• the present invention relates to an optical disk and a sputtering target for a Cu alloy recording layer, and particularly when a protective layer containing ZnS (for example, ZnS-SiO 2) is used, recording bit errors do not occur.
• a protective layer containing ZnS for example, ZnS-SiO 2
• the present invention relates to an optical disc and a sputtering target for a Cu alloy recording layer that can obtain a large optical recording medium.
• This optical disc can be divided into three types: read-only type, write-once type, and rewritable type.
• write-once type optical discs (Write-once recording) require high-speed recording and large-capacity writing.
• Such an optical disc records information by heating and heating a recording thin film on a substrate by irradiating a laser beam to change the structure of the recording thin film.
• information is reproduced by detecting changes in reflectance caused by changes in optical constants.
• the phase change described above is performed by laser light irradiation with a diameter of about 1 to several / zm.
• a l / zm laser beam passes at a linear velocity of 10 m / S
• the time at which a point of the optical disk is irradiated with light is 100 ns. It is necessary to detect the reflectance.
• an optical disc has a structure in which a recording layer is sandwiched with a protective layer or a structure in which one side of the recording layer is covered with a protective layer.
• Cu / Si as the recording layer of next-generation optical disks (see Non-Patent Document 1).
• the Cu recording layer is irradiated with a laser to cause Cu and Si to react, and the structure between Cu / Si is changed to produce a crystal structure change.
• Write only, not append or rewrite Briefly explaining the disk structure described in this Non-Patent Document 1, this disk relates to a double structure inorganic material-based write-once disk that uses blue light, and a Cu alloy adjacent to the Si layer.
• This recording medium is sandwiched between protective layers.
• a double structure is formed through the sandwich-shaped cassette layer, and is further placed on a PC (polycarbonate) substrate through a reflective layer.
• a cover layer is provided on the surface layer.
• the present invention relates to an optical disk and a sputtering target for a Cu alloy recording layer, and particularly when a protective layer containing Zn S (for example, ZnS-SiO 2) is used, the S from the protective layer is used.
• a protective layer containing Zn S for example, ZnS-SiO 2
• an optical disc and a Cu alloy recording layer sputtering target capable of preventing or suppressing the Cu recording layer from being diffused due to diffusion and obtaining an optical recording medium free from recording bit errors.
• the present invention is based on this knowledge, and in an optical disc having a structure in which the recording layer is adjacent to a protective layer containing ZnS, the recording layer is composed of one or more components selected from Zn, Mn, Ga, Ti, Ta in a total amount of 1 to
• the present invention provides an optical disk using a Cu alloy recording layer containing 20 at% and the balance being Cu and inevitable impurities.
• the optical disk of the present invention is one in which impurities of Mg, Na, Ca, Ba, Ce, Li, and Zr present in the Cu alloy recording layer are each 0.1 at% or less. If this impurity exceeds 0.1 &%, it will be difficult to suppress damage caused by S diffusing from the protective layer containing ZnS. It can be said that it is desirable to reduce as much as possible.
• the present invention forms a Cu alloy recording layer by sputtering, and the sputtering target for the Cu alloy recording layer itself contains a total amount of one or more components selected from Zn, Mn, Ga, Ti, Ta. In this case, 1 to 20 at% is contained, and the balance is Cu and an inevitable impurity copper alloy.
• impurities of Mg, Na, Ca, Ba, Ce, Li, and Zr present in the Cu alloy must be 0.1 at% or less, respectively. Is desirable.
• the sputtering target for an optical disk and a Cu alloy recording layer according to the present invention is caused by diffusion of S from the protective layer, particularly when a protective layer containing ZnS (for example, ZnS-SiO 2) is used.
• a protective layer containing ZnS for example, ZnS-SiO 2
• FIG. 1 is a diagram showing the relationship between the standard free energy of formation of sulfur and the temperature (a).
• FIG. 2 A diagram showing the relationship between the standard free energy of formation and the temperature of sulfur (b).
• FIG. 3 is a diagram showing the measurement results of reflectivity in an anticorrosion acceleration test with Zn addition in Example 1.
• FIG. 4 is a graph showing the measurement results of reflectance in an accelerated corrosion test with Mn added in Example 2.
• FIG. 5 is a diagram showing a measurement result of reflectance in an anticorrosion acceleration test with addition of A1 in Comparative Example 1
• FIG. 6 is a diagram showing the measurement results of reflectance in the corrosion prevention acceleration test with Mg addition of Comparative Example 2.
• FIG. 7 is a diagram showing a measurement result of reflectance in an anticorrosion acceleration test with addition of B in Comparative Example 3.
• A1 is a material that has a strong acidity, because dense A10 is formed on the surface.
• MgO is a similar material.
• the standard free energy of formation of acid oxides is It is considered effective to select a small material.
• the A1 additive which has a much lower standard generation energy of sulfur than the base material Cu, has a little anticorrosion (sulfuration prevention) effect, but is insufficient (comparison described later).
• the result was that Cu sulfur was promoted rather (see Comparative Example 2 described later).
• Examples of the material suitable for this include metal elements selected from Zn, Mn, Ga, Ti, and Ta.
• As for the force, l ⁇ 20at% of additive is effective. Less than lat%, the effect of the additive is not good. The additive of more than 20at% is unfavorable because it reduces the role of the Cu recording layer. [0017] The reason for such a phenomenon is not necessarily clear in theory, but is presumed as follows. This will be described below.
• ZnS is a stable compound when Zn and S are 1: 1 respectively.
• ZnS does not necessarily have a 1: 1 stoichiometric composition, but within the composition range. May be Zn-rich and S-rich.
• ZnS having a composition used as such a protective layer is formed by sputtering, but when the S-rich portion is partially formed or the sputtering target itself is formed in S-rich, the composition is not a film. It is highly possible that an S-rich layer is formed on almost the entire surface of the film. In such cases, S-rich ZnS is thought to cause Cu corrosion.
• this additive is a metal element selected from Zn, Mn, Ga, Ti, and Ta, and Zn and Mn are particularly effective.
• Zn, Mn, Ga, Ti, and Ta Zn and Mn are particularly effective.
• the sulfide itself is transparent and does not absorb light, the function as a recording layer is not deteriorated.
• the above Mg is a force that is an element that forms a stable sulfide with low standard generation energy.
• This Mg promotes the dissociation of S from ZnS and makes ZnS unstable. It is thought to promote the formation of active S and reduce the function as a protective film.
• B which has a standard energy of production slightly lower than that of CuS, it can be said that B does not have the effect of addition because it does not have enough activity to prevent the formation of CuS.
• Fig. 1 and Fig. 2 show the relationship between the standard production energy and temperature of a series of sulfurized products.
• Figure 1 shows the Steel Handbook (Third Edition), Volume 1, page 12, ⁇ Basic Theory ( Figure l'3 (b) Standard Free Energy and Temperature (Relationship with Degree) ”, published by Japan Steel Association, published by Maruzen (published on October 30, 1986, second print).
• Fig. 2 is based on the thermodynamics of Swallin solids, Fig. 7.8 "Relationship between standard free energy and temperature of sulfate", published by Corona (published 15th edition on March 25, 1992).
• such elements are Mg, Na, Ca, Ba, Ce, Li, and Zr, and these impurities are preferably 0.1 at% or less.
• the anticorrosion test was done with respect to these.
• the anticorrosion test was an accelerated test at constant temperature and humidity (85 ° C, 85%, 100 hours).
• the state of corrosion was compared by visual observation and reflectance measurement before and after the acceleration test.
• Table 1 shows the results of this anti-corrosion test by visual observation.
• Figure 3 shows the reflectivity measurement results.
• Table 1 shows the overall evaluation of each additive element, standard free energy AG [kcal / mol S2] for sulfide formation at 300K, and corrosion protection.
• the standard formation energy of ZnS at 300K is -112 kcal / mol S2, but the anticorrosion effect of Zn-added potassium, which is an additive material with the same standard formation energy of ZnS and sulfate formation, was extremely high and good.
• the reflectivity is slightly lower than the Cu corrosion test only in the long-term accelerated test of 100 hours at a Zn content of 20 at%, but the others are almost the same. There is almost no decrease in reflectivity, and it can be seen that Zn-added powder is extremely effective.
• the anticorrosion test was done with respect to these.
• the anticorrosion test was an accelerated test at constant temperature and humidity (85 ° C, 85%, 100 hours).
• the state of corrosion was compared by visual observation and reflectance measurement before and after the acceleration test.
• Table 1 shows the results of this anticorrosion test.
• the reflectance measurement results are shown in Fig. 4.
• ⁇ ⁇ of Ga is -117
• AG of Ti is -116
• AG of Ta is -102, both of which are the standard production energies of ZnS at 300K-range from -112kcal / mol S2 to ⁇ 20 It is an element that forms a sulfide with a standard production energy. Therefore, these additives can obtain the same effects as Zn and Mn. In addition, the same effect can be obtained with these composite additives.
• a material in which A1 was added to lat%, 5at%, 10at%, and 20at% in Cu was melted in an arc melting furnace to create an ingot, and then four types of Cu-Al alloy samples were prepared. For comparison, a Cu ingot was also prepared. After polishing the surface of these samples, etching was performed with nitric acid, and a ZnS-SiO film was further coated thereon.
• the anticorrosion test was done with respect to these.
• the anticorrosion test was an accelerated test at constant temperature and humidity (85 ° C, 85%, 100 hours).
• the state of corrosion was compared by visual observation and reflectance measurement before and after the acceleration test.
• Table 1 shows the results of this anticorrosion test.
• Figure 5 shows the reflectivity measurement results.
• the anti-corrosion effect of the A1 additive which is an additive material that separates the standard formation energy of ZnS and sulfide formation, was slightly inferior.
• the one with A1 added shows a significant decrease in reflectivity with the time of the anticorrosion test, where the reflectivity varies more than Cu alone. As a result, it can be seen that the A1-added coffee is significantly inferior.
• the material was melted in an arc melting furnace and ingots were prepared, and then four types of Cu-Mg alloy samples were prepared. For comparison, a Cu ingot was also created. After polishing the surface of these samples, etching was performed with nitric acid, and a ZnS-SiO film was further coated thereon.
• the anticorrosion test was done with respect to these.
• the anticorrosion test was an accelerated test at constant temperature and humidity (85 ° C, 85%, 100 hours).
• the state of corrosion was compared by visual observation and reflectance measurement before and after the acceleration test.
• Table 1 shows the results of this anticorrosion test.
• Figure 6 shows the reflectivity measurement results.
• the anticorrosion test was done with respect to these.
• the anticorrosion test was an accelerated test at constant temperature and humidity (85 ° C, 85%, 100 hours).
• the state of corrosion was compared by visual observation and reflectance measurement before and after the acceleration test.
• Table 1 shows the results of this anticorrosion test.
• Figure 7 shows the reflectivity measurement results.
• the sputtering target for an optical disk and a Cu alloy recording layer of the present invention has a Cu recording layer formed by diffusion of S from the protective layer, particularly when ZnS-SiO is used as the protective layer.
• optical disc material capable of preventing or suppressing the formation of errors, producing an optical recording medium without occurrence of recording bit errors, and capable of high-speed recording and large-capacity writing, and for Cu alloy recording layers It is extremely useful as a sputtering target.

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• Chemical & Material Sciences (AREA)
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• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Thermal Transfer Or Thermal Recording In General (AREA)
• Optical Record Carriers And Manufacture Thereof (AREA)
• Manufacturing Optical Record Carriers (AREA)

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• 2006
  • 2006-04-07 JP JP2007523348A patent/JP4603044B2/ja not_active Expired - Fee Related
  • 2006-04-07 CN CN2006800244989A patent/CN101218106B/zh not_active Expired - Fee Related
  • 2006-04-07 WO PCT/JP2006/307434 patent/WO2007004344A1/ja not_active Ceased
  • 2006-04-07 EP EP06731381A patent/EP1900540B1/en not_active Ceased
  • 2006-04-14 TW TW095113343A patent/TW200706674A/zh not_active IP Right Cessation

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