TW201401277A - Alloy target for recording layer, recording layer, optical recording media and blu-ray disc comprising the same - Google Patents

Abstract

In view of the low recording speed and recording quality of a conventional recording media comprising double recording layer due to its high phase transition temperature, the present invention provides an alloy target, a recording layer, an optical recording media, and a blu-ray disc including (CuaSib)xM1-x alloy to overcome the aforementioned shortcomings. Because the (CuaSib)xM1-x alloy includes an anti-corrosive element (M) which is capable of preventing the copper from being oxidized, the phase transition temperature of a recording layer can be improved within 150 DEG C and 425 DEG C. Therefore, (CuaSib)xM1-x alloy is a favorable material applying to a recording layer in an optical recording media, so that a blu-ray disc including (CuaSib)xM1-x alloy with advantages of high recording stability and rapid recording speed is provided in accordance with the present invention.

Description

Alloy target for recording layer, recording layer, optical recording medium and the same Blu-ray disc

The present invention relates to an alloy target for a recording layer, a recording layer, and an optical recording medium, and more particularly to an alloy target containing a corrosion-resistant element, a recording layer, and an optical recording medium. Further, the present invention relates to a write-once type Blu-ray disc including the aforementioned recording layer.

Blu-ray Disc (Blu-ray Disc) is named after the use of blue laser light with a wavelength of 405 nm for data reading and writing. It is the next generation optical disc specification for data storage media and has been widely used to store high-capacity data. Or high quality audio and video files.

In blue light discs, the single-write type blue light disc of the Cu/Si system utilizes a metal induced crystallization phase change mechanism to enable amorphous germanium to be borrowed at a lower phase transition temperature. The amorphous metal is induced to crystallize by copper metal, and the in-situ reflectivity of the recording layer to the blue laser light is improved, and the data recording work is completed.

In the prior art Cu/Si system single-write type optical recording medium, the common layered structure sequentially includes a substrate, a reflective layer, a first dielectric layer, a dual recording layer, a second dielectric layer and a protective layer. Wherein, the double recording layer is composed of a copper layer and an amorphous germanium layer. Since the phase transition temperature of the prior art dual recording layer is too high (about 500 ° C), the writing power of the Blu-ray disc (at least 8 mW) must be increased to produce a higher temperature on the surface of the double recording layer, so that the phase can be smoothly performed. The transformation, and thus the completion of data recording, and increasing the write power of the Blu-ray disc will increase the burning cost of the optical recording medium.

In order to overcome the above problems, many people have tried to improve the material of the double recording layer in the prior art optical recording medium, and replace the original copper layer with a copper beryllium alloy, because the copper beryllium alloy is sputtered on the amorphous germanium layer. The reaction with the amorphous ruthenium layer produces a crystal phase of Cu ₃ Si, and thus crystals can be formed at a lower temperature. However, the phase transition temperature of the copper-bismuth alloy is too low, so that the copper metal is liable to spontaneously react and oxidize, and the recording quality of the optical recording medium is deteriorated.

In order to overcome the problems faced by the prior art, the main object of the present invention is to design an alloy material suitable as a recording layer of an optical recording medium, which can have an appropriate phase transition temperature, thereby improving the burning speed and recording of the optical recording medium. quality.

In order to achieve the foregoing object, the present invention provides an alloy target for a recording layer which is composed of (Cu _a Si _b ) _x M _1-x alloy, wherein the M system is nickel, chromium, molybdenum or titanium, and the a system is Between 0.65 and 0.75, the b series is between 0.25 and 0.35 and the X series is between 0.9 and 0.99.

Preferably, the base phase of the alloy target is a copper beryllium alloy, and the compound phase of the alloy target is a bismuth nickel alloy, a bismuth chrome alloy, a bismuth molybdenum alloy or a bismuth titanium alloy. .

Preferably, the alloy target is produced by powder metallurgy or smelting.

In order to achieve the above object, the present invention further provides a recording layer for an optical recording medium comprising (Cu _a Si _b ) _x M _1-x alloy, wherein the M system is nickel, chromium, molybdenum or titanium, a system Between 0.65 and 0.75, b is between 0.25 and 0.35, and X is between 0.9 and 0.99.

In the recording layer for an optical recording medium of the present invention, the composition of the copper ruthenium eutectic point (Cu ₃ Si) can increase the rate at which the recording layer undergoes phase transition by laser irradiation, and simultaneously reduce the transition of the recording layer from an amorphous state. It is the phase transition temperature of the crystalline state.

Herein, the M system is a corrosion-resistant element, which can be used to prevent oxidation of copper metal, and the phase transition temperature of the (Cu _a Si _b ) _x M _1-x alloy is between 150 ° C and 425 ° C. An alloy material suitable as a recording layer of a high-speed optical recording medium.

Preferably, the recording layer is sputtered from the alloy target.

In order to achieve the foregoing object, the present invention further provides an optical recording medium comprising: a substrate; a reflective layer disposed on the substrate; a first dielectric layer disposed on the reflective layer; a layer disposed on the first dielectric layer, wherein the dual recording layer comprises an amorphous germanium layer and an alloy material layer, and the alloy material layer is composed of (Cu _a Si _b ) _x M _1-x The composition of the alloy, wherein the M system is nickel, chromium, molybdenum or titanium, the a system is between 0.65 and 0.75, the b system is between 0.25 and 0.35, and the X series is between 0.9 and 0.99; a dielectric layer disposed on the dual recording layer; and a protective layer disposed on the second dielectric layer.

Here, the amorphous germanium layer and the alloy material layer in the double recording layer can be replaced up and down.

In an embodiment of the optical recording medium of the present invention, the amorphous germanium layer may be disposed on the first dielectric layer, and the alloy material layer may be disposed on the amorphous germanium layer and the second dielectric layer. between. Alternatively, in another embodiment of the optical recording medium of the present invention, the alloy material layer may be disposed on the first dielectric layer, and the amorphous germanium layer may be disposed on the alloy material layer and the second dielectric Between the layers.

Preferably, the substrate can be a PC substrate.

Preferably, the reflective layer may be a pure silver metal, a silver alloy, a pure gold metal, a gold alloy, an aluminum alloy or a copper alloy.

Preferably, the first dielectric layer and the second dielectric layer may be zinc sulfide (ZnS), zinc sulfide-cerium oxide (ZnS-SiO ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), Indium Tin Oxide (ITO), tantalum nitride (Si ₃ N ₄ ), yttrium oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), aluminum nitride (AlN), tantalum carbide (SiC) ), tantalum nitride (Ge ₃ N ₄ ), titanium nitride (Ti ₃ N ₄ ) or yttrium oxide (Y ₂ O ₃ ).

Preferably, the protective layer may be ceria-aluminum oxide (CeO ₂ -Al ₂ O ₃ ), bismuth chromium alloy (GeCr), titanium dioxide (TiO ₂ ), indium tin oxide (ITO). .

Preferably, the double recording layer has a thickness of 5 nm to 30 nm.

Preferably, the thickness of the alloy material layer can be between 2 nm and 30 nm.

Preferably, the reflective layer has a thickness of between 80 nm and 120 nm.

Preferably, the thickness of the reflective layer, the first dielectric layer, the dual recording layer, the second dielectric layer and the protective layer is between 10 mm and 200 mm.

In order to achieve the foregoing object, the present invention further provides a Blu-ray disc comprising a recording layer for an optical recording medium as described above.

Preferably, the Blu-ray disc may have a layered structure like the aforementioned optical recording medium.

Preferably, the Blu-ray disc is a single-write type Blu-ray disc.

Preferably, the recording speed of the Blu-ray disc is up to 6X (216 Mbit/s).

In summary, the present invention designs a (Cu _a Si _b ) _x M _1-x alloy material having a phase transition temperature between 150 ° C and 425 ° C, and uses (Cu _a Si _b ) _x M _1-x alloy material as The material of the recording layer of the optical recording medium can cause the optical recording medium to not spontaneously react and oxidize at a low temperature, and can rapidly undergo phase transition through blue laser light at a high-speed burning speed (short contact time). A recording layer material of an optical recording medium having high stability and high-speed burning.

In the following, the embodiments of the present invention will be described by way of specific examples, and those skilled in the art can readily understand the advantages and functions of the present invention, and can carry out various kinds without departing from the spirit of the present invention. Modifications and variations are made to implement or apply the subject matter of the invention.

First, the manufacturing steps of the present invention will be described:

1. Making an alloy target for a recording layer a. Example 1: (Cu _0.65 Si _0.35 ) _0.95 Ni _0.05 Alloy target

848.5 g of copper powder, 201.9 g of bismuth powder and 63.5 g of nickel powder are uniformly mixed, and the temperature is maintained at 600-800 ° C and the pressure is about 500 bar, and the hot pressing is continued for 3 hours to obtain (Cu _0.65 Si). _0.35 ) _0.95 Ni _0.05 alloy target.

Wherein the overall content of copper-based accounting _{(Cu 0.65 Si 0.35) 0.95 Ni} 0.05 61.75at% of the alloy, the content of silicon-based accounting _0.95 Ni _{0.05 33.25at%} overall whole alloy (Cu _0.65 Si _0.35), accounting for the overall system and the nickel content ( 5 at% of Cu _0.65 Si _0.35 ) _0.95 Ni _0.05 alloy.

b. Example 2: (Cu _0.7 Si _0.3 ) _0.95 Ni _0.05 Alloy target

99.2 g of copper powder, 177.9 g of bismuth powder and 65.2 g of nickel powder are uniformly mixed, and the temperature is maintained at 600-800 ° C and the pressure is about 500 bar, and the hot pressing is continued for 3 hours to obtain (Cu _0.7 Si). _0.3 ) _0.95 Ni _0.05 alloy target.

Wherein the overall content of copper-based accounting _{(Cu 0.7 Si 0.3) 0.95 Ni} 0.05 66.5at% alloy, the content of silicon-based accounting _0.95 Ni _{0.05 28.5at%} overall whole alloy (Cu _0.7 Si _0.3), accounting for the overall system and the nickel content ( 5 _0.7 % of Cu _0.7 Si _0.3 ) _0.95 Ni _0.05 alloy.

As shown in FIG. 1 , the gray phase is a base phase of an alloy target, which is mainly composed of a copper beryllium alloy; and the black phase is a compound phase of an alloy target, which is mainly composed of a niobium nickel alloy. .

c. Example 3: (Cu _0.75 Si _0.25 ) _0.95 Ni _0.05 Alloy target

1035 g of copper powder, 152.5 g of bismuth powder and 67.1 g of nickel powder are uniformly mixed, and the temperature is maintained at 600-800 ° C and the pressure is about 500 bar, and the hot pressing is continued for 3 hours to obtain (Cu _0.75 Si). _0.25 ) _0.95 Ni _0.05 alloy target.

Wherein the overall content of copper-based accounting _{(Cu 0.75 Si 0.25) 0.95 Ni} 0.05 71.25at% of the alloy, the content of silicon-based accounting _0.95 Ni _{0.05 23.75at%} overall whole alloy (Cu _0.75 Si _0.25), accounting for the overall system and the nickel content ( Cu _0.75 Si _0.25 ) _0.95 Ni _0.05 alloy 5at%.

d. Example 4: (Cu _0.7 Si _0.3 ) _0.98 Ni _0.02 Alloy target

962.1 g of copper powder, 182.2 g of niobium powder and 25.9 g of nickel powder were uniformly mixed, and the temperature was maintained at 600-800 ° C and the pressure was about 500 bar, and the hot pressing was continued for 3 hours to obtain (Cu _0.7 Si). _0.3 ) _0.98 Ni _0.02 alloy target.

Among them, the copper content accounts for 68.6at% of the whole (Cu _0.7 Si _0.3 ) _0.98 Ni _0.02 alloy, and the niobium content accounts for 29.4at% of the whole whole (Cu ₀ . ₇ Si _0.3 ) _0.98 Ni _0.02 alloy, and the nickel content accounts for 2at% of the overall (Cu _0.7 Si _0.3 ) _0.98 Ni _0.02 alloy.

e. Example 5: (Cu _0.65 Si _0.35 ) _0.95 Cr _0.05 Alloy target

845.4 g of copper powder, 201.2 g of bismuth powder and 56 g of chrome powder are uniformly mixed, and the temperature is maintained at 600-800 ° C and the pressure is about 500 bar, and the hot pressing is continued for 3 hours to obtain (Cu _0.65 Si). _0.35 ) _0.95 Cr _0.05 alloy target.

Among them, the copper content accounts for 61.75at% of the whole (Cu _0.65 Si _0.35 ) _0.95 Cr _0.05 alloy, and the niobium content accounts for 33.25at% of the whole whole (Cu _0.65 Si _0.35 ) _0.95 Cr _0.05 alloy, and the chromium content is the whole ( 5 at% of Cu _0.65 Si _0.35 ) _0.95 Cr _0.05 alloy.

f. Example 6: (Cu _0.7 Si _0.3 ) _0.98 Cr _0.02 Alloy target

960.6 g of copper powder, 182 g of bismuth powder and 22.9 g of chrome powder are uniformly mixed, and the temperature is maintained at 600-800 ° C and the pressure is about 500 bar, and the hot pressing is continued for 3 hours to obtain (Cu _0.7 Si). _0.3 ) _0.98 Cr _0.02 alloy target.

Among them, the copper content accounts for 68.6at% of the whole (Cu _0.7 Si _0.3 ) _0.98 Cr _0.02 alloy, and the niobium content accounts for 29.4at% of the whole whole (Cu _0.7 Si _0.3 ) _0.98 Cr _0.02 alloy, and the chromium content is the whole ( Cu _0.7 Si _0.3 ) 2at% of _0.98 Cr _0.02 alloy.

As shown in FIG. 2, the light gray phase is a base phase of an alloy target, which is mainly composed of a copper beryllium alloy; and the dark gray phase is a compound phase of an alloy target, which is mainly composed of a lanthanum chromium alloy. Composed of.

g. Example 7: (Cu _0.75 Si _0.25 ) _0.95 Cr _0.05 Alloy target

1031 g of copper powder, 151.9 g of bismuth powder and 59.2 g of chrome powder are uniformly mixed, and the temperature is maintained at 600-800 ° C and the pressure is about 500 bar, and the hot pressing is continued for 3 hours to obtain (Cu _0.75 Si). _0.25 ) _0.95 Cr _0.05 alloy target.

Wherein the overall content of copper-based accounting _{(Cu 0.75 Si 0.25) 0.95 Cr} 0.05 71.25at% of the alloy, the content of silicon-based accounting for _0.95 Cr _{0.05 23.75at%} overall whole alloy (Cu _0.75 Si _0.25), accounting for the overall system and the nickel content ( 5 at% of Cu _0.75 Si _0.25 ) _0.95 Cr _0.05 alloy.

h. Example 8: (Cu _0.7 Si _0.3 ) _0.98 Mo _0.02 Alloy target

955.8 g of copper powder, 181 g of bismuth powder and 42.1 g of molybdenum powder were uniformly mixed, and the temperature was maintained at 600-800 ° C and the pressure was about 500 bar, and the hot pressing was continued for 3 hours to obtain (Cu _0.7 Si). _0.3 ) _0.98 Mo _0.02 alloy target.

Among them, the copper content accounts for 68.6at% of the whole (Cu _0.7 Si _0.3 ) _0.98 Mo _0.02 alloy, and the niobium content accounts for 29.4at% of the whole whole (Cu _0.7 Si _0.3 ) _0.98 Mo _0.02 alloy, and the molybdenum content is the whole ( Cu _0.7 Si _0.3 ) 2at% of _0.98 Mo _0.02 alloy.

i. Example 9: (Cu _0.7 Si _0.3 ) _0.98 Ti _0.02 Alloy target

953.1 g of copper powder, 180.5 g of bismuth powder and 20.9 g of titanium powder were uniformly mixed, and the temperature was maintained at 600-800 ° C and the pressure was about 500 bar, and the hot pressing was continued for 3 hours to obtain (Cu _0.7 Si). _0.3 ) _0.98 Ti _0.02 alloy target.

Among them, the copper content accounts for 68.6at% of the whole (Cu _0.7 Si _0.3 ) _0.98 Ti _0.02 alloy, and the niobium content accounts for 29.4at% of the whole whole (Cu _0.7 Si _0.3 ) _0.98 Ti _0.02 alloy, and the titanium content accounts for the whole ( Cu _0.7 Si _0.3 ) 2at% of _0.98 Ti _0.02 alloy.

j. Comparative Example 1: (Cu _0.7 Si _0.3 ) _0.89 Ni _0.11 Alloy target

892.4 g of copper powder, 169.0 g of bismuth powder and 145.6 g of nickel powder were uniformly mixed, and the temperature was maintained at 600-800 ° C and the pressure was about 500 bar, and the hot pressing was continued for 3 hours to obtain (Cu _0.7 Si). _0.3 ) _0.98 Ti _0.02 alloy target.

Among them, the copper content accounts for 62.3at% of the whole (Cu _0.7 Si _0.3 ) _0.89 Ni _0.11 alloy, and the niobium content accounts for 26.7at% of the whole whole (Cu _0.7 Si _0.3 ) _0.89 Ni _0.11 alloy, and the titanium content accounts for the whole ( Cu _0.7 Si _0.3 ) 11 at% of _0.89 Ni _0.11 alloy.

2. Making optical recording media

Referring to FIG. 3, first, a PC substrate 1 is provided. Next, a reflective layer 2 of pure silver and a first dielectric layer 3 of ZnS-SiO ₂ are sequentially formed on the PC substrate 1. Here, the thickness of the PC substrate 1 is about 1.1 mm, the thickness of the reflective layer 2 is 100 nm, and the thickness of the first dielectric layer 3 is 15-50 nm.

Next, using _a (Cu _a Si _b ) _x M _1-x alloy target obtained by the above-described fabrication method, a thickness is sputtered on the first dielectric layer 3 in a vacuum chamber having a pressure of 3 m torr. An alloy material layer 41 of about 2-30 nm (Cu _a Si _b ) _x M _1-x . Thereafter, an amorphous germanium layer 42 is deposited on the alloy material layer 41 of (Cu _a Si _b ) _x M _1-x such that the thickness of the double recording layer 4 is about 5 to 50 nm.

Then, the second dielectric layer 5 of ZnS-SiO ₂ and the protective layer 6 of CeO ₂ -Al ₂ O ₃ are sequentially formed on the double recording layer 4, that is, the fabrication of the optical recording medium is completed. The thickness of the second dielectric layer 5 is about 15-50 nm, and the thickness of the protective layer 6 is about 2-10 nm.

In addition, in an optical recording medium according to another embodiment of the present invention, the amorphous germanium layer 42 may be disposed on the first dielectric layer 3, and then formed on the amorphous germanium layer 42 (Cu _a Si _b ). _x M _1-x alloy material layer 41. The layered structure of the detailed optical recording medium is shown in FIG.

Next, the phase transition temperatures of the recording layers for optical recording media in the respective examples and comparative examples are as follows:

Referring to the above table, the phase transition temperature of the double recording layer of Comparative Example 1 is 243 ° C and 441 ° C. When such an alloy material is used as the double recording layer material of the optical recording medium, the optical recording medium is recorded at a high speed. The phase transition needs to occur in a short period of time, and the excessive phase transition temperature will not be able to completely crystallization reaction, resulting in incomplete recording of the optical recording medium and affecting the electrical signal. Therefore, the use of the alloy material layer formed by the alloy sputtering target of Comparative Example 1 is not suitable for producing a single-write type Blu-ray disc of high-speed recording.

The first phase transition temperature of the double recording layer of Comparative Example 2 is lower than 150 ° C, so that the copper metal is liable to spontaneously react and oxidize, so that the instantaneous reflectance intensity of the optical recording medium is low, and the recording layer material of Comparative Example 2 is shown. It is not suitable as a recording layer material for a high-speed optical recording medium.

Referring to the above table, the phase transition temperature of the double recording layer of Comparative Example 3 is too high, and the recording layer cannot be rapidly changed from an amorphous state to a crystalline state, and thus is not suitable as a recording layer material of a high-speed optical recording medium.

In addition, please refer to the above table and FIG. 5, the double recording layers of Embodiment 2, Embodiment 4 and Embodiment 6 have a first phase transition temperature and a second phase transition temperature of 150 ° C to 425. Between °C, it can be used as a material for recording layers of optical recording media with high stability and high-speed burning. As shown in FIG. 5, the double recording layers of Example 2, Example 4, and Example 6 have strong immediate reflectance strength between 300 ° C and 425 ° C compared to the instant reflectance intensity of Comparative Example 2. . The experimental results confirmed that the (Cu _a Si _b ) _x M _1-x alloy of the present invention can be used as a material of a double recording layer of an optical recording medium, and greatly improves the burning speed of an optical recording medium such as a Blu-ray disc.

The above-mentioned embodiments are merely examples for convenience of description, and the scope of the claims is intended to be limited to the above embodiments.

1‧‧‧Substrate

2‧‧‧reflective layer

3‧‧‧First dielectric layer

4‧‧‧ double recording layer

41‧‧‧ alloy material layer

42‧‧‧Amorphous layer

5‧‧‧Second dielectric layer

6‧‧‧Protective layer

1 is a metallographic diagram of a (Cu _0.7 Si _0.3 ) _0.95 Ni _0.05 alloy target of Example 2 of the present invention.

2 is a metallographic diagram of a (Cu _0.7 Si _0.3 ) _0.98 Cr _0.02 alloy target of Example 6 of the present invention.

3 is a schematic view showing a layered structure of an optical recording medium according to an embodiment of the present invention.

Fig. 4 is a schematic view showing the layered structure of an optical recording medium according to another embodiment of the present invention.

Fig. 5 is a graph showing the results of instantaneous reflectance of the optical recording media of Examples 2, 4, and 6 and Comparative Example 2 at different temperatures.

1‧‧‧Substrate

2‧‧‧reflective layer

3‧‧‧First dielectric layer

4‧‧‧ double recording layer

41‧‧‧ alloy material layer

42‧‧‧Amorphous layer

5‧‧‧Second dielectric layer

6‧‧‧Protective layer

Claims (9)

An alloy target for a recording layer, which is composed of (Cu _a Si _b ) _x M _1-x alloy, wherein the M system is nickel, chromium, molybdenum or titanium, and the X system is between 0.9 and 0.99, a The line is between 0.65 and 0.75 and the b series is between 0.25 and 0.35. A recording layer for an optical recording medium, which is composed of (Cu _a Si _b ) _x M _1-x alloy, wherein the M system is nickel, chromium, molybdenum or titanium, and the X series is between 0.9 and 0.99, a The line is between 0.65 and 0.75 and the b series is between 0.25 and 0.35. The recording layer for an optical recording medium according to claim 2, wherein the recording layer is sputtered by the alloy target as claimed in claim 1. An optical recording medium comprising: a substrate; a reflective layer disposed on the substrate; a first dielectric layer disposed on the reflective layer; and a dual recording layer disposed on the first a dielectric layer, wherein the dual recording layer comprises an amorphous germanium layer and an alloy material layer, and the alloy material layer is composed of (Cu _a Si _b ) _x M _1-x alloy, wherein the M system is nickel , chromium, molybdenum or titanium, X series between 0.9 and 0.99, a series between 0.65 and 0.75, b series between 0.25 and 0.35; a second dielectric layer, which is set in the double a recording layer; a protective layer disposed on the second dielectric layer. The optical recording medium of claim 4, wherein the amorphous germanium layer is disposed on the reflective layer, and the alloy material layer is disposed between the amorphous germanium layer and the second dielectric layer. The optical recording medium of claim 4, wherein the alloy material layer is disposed on the reflective layer, and the amorphous germanium layer is disposed between the alloy material layer and the second dielectric layer. The optical recording medium of claim 4, wherein the double recording layer has a thickness of from 5 nm to 30 nm. A Blu-ray disc comprising a recording layer for an optical recording medium as claimed in claim 2 or 3. The Blu-ray disc of claim 8, which is a single-write type Blu-ray disc.