WO2004022813A1

WO2004022813A1 - Sputtering target and optical recording medium

Info

Publication number: WO2004022813A1
Application number: PCT/JP2003/009996
Authority: WO
Inventors: Masataka Yahagi; Hideo Takami
Original assignee: Nikko Materials Co., Ltd.
Priority date: 2002-09-09
Filing date: 2003-08-06
Publication date: 2004-03-18
Also published as: JP2004158049A; CN100445418C; TW200406497A; TWI275652B; CN1681958A; JP4817137B2

Abstract

A sputtering target composed mainly of zinc sulfide characterized in that conductive oxide and nitride are contained; and an optical recording medium provided with a phase change type optical disk protective film composed mainly of zinc sulfide and produced with the use of the sputtering target. In particular, a sputtering target composed mainly of zinc sulfide which when used to form a film by sputtering, can reduce the occurrence of particles and nodules at sputtering and can attain suppression of quality dispersion and increase of mass production efficiency, and which comprises fine crystal grains and exhibits a bulk resistance of 5 × 10-2 Ωcm or below, having a density as high as 90% or above; and an optical recording medium provided with a phase change type optical disk protective film composed mainly of zinc sulfide and produced with the use of the sputtering target.

Description

Sputtering target and optical recording medium

In the present invention, when forming a film by sputtering, direct current (DC) sputtering can be performed, arcing at the time of sputtering can be reduced, and particles (dust generation) and nodules generated due to this can be reduced. Also, a zinc sulfide-based sputtering tongue and a zinc sulfide-based zinc sulfide-based phase which are high in density and capable of improving mass productivity with little variation in quality The present invention relates to an optical recording medium on which a changeable optical disc protective film is formed. Background art

In recent years, high-density recording optical disc technology capable of recording and reproduction without the need for magnetic heads has been developed, and interest is rapidly increasing. The optical disc is divided into three types: read-only type, write-once type, and rewritable type. Particularly, a phase change type used in the write-once type or the rewritable type attracts attention. The principle of recording and reproduction using this phase change type optical disc will be briefly described below.

A phase change optical disc heats and raises the temperature of a recording thin film on a substrate by laser irradiation, causing crystallographic phase change (amorphous crystal) in the structure of the recording thin film to record and reproduce information. Specifically, information is reproduced by detecting a change in reflectance resulting from a change in optical constant between the phases.

The above-mentioned phase change is performed by the irradiation of the laser beam narrowed to a diameter of about 1 to several / x m. In this case, for example, when a laser beam of 1 passes at a linear velocity of 1 O mZ s, the time for which light is irradiated to a certain point of the optical disc is 100 ns, and the phase change occurs during this time. And reflectance detection needs to be done.

Further, in order to realize the above-mentioned crystallographic phase change, that is, the phase change between amorphous and crystal, melting and quenching not only for the phase change recording layer of the optical disc but also for the peripheral dielectric protective layer and the reflection film of aluminum alloy. 'Will also be given repeatedly. For this reason, phase change optical disks are made of zinc sulfide-key oxide (Z n S · S i _{2 2} ) based high melting point dielectrics on both sides of the recording thin film layer such as Ge-S b-T e. It has a four-layer structure in which an aluminum alloy reflective film is provided by sandwiching it with a protective layer.

Among them, the reflective layer and the protective layer are required to have an optical function which increases the absorption between the amorphous part and the crystalline part and the difference in reflectance is large, and also functions to prevent the moisture resistance of the recording thin film and the deformation due to heat. The function of thermal condition control at the time of recording is required (refer to the magazine "Optics" 26 volume 1 page 9 to 15).

Thus, the protective layer of the high melting point dielectric is resistant to the cyclic stress of heat due to the temperature rise and the cooling, and further, the thermal influence of these does not affect the reflective film and other places, and As such, it must be thin, have low reflectivity, and have toughness that does not deteriorate. In this sense, the dielectric protective layer plays an important role.

The dielectric protective layer is usually formed by sputtering. In this sputtering method, a target consisting of a positive electrode and a negative electrode is opposed, and a high voltage is applied between the substrate and the target in an inert gas atmosphere to generate an electric field. At this time, the ionized electrons collide with the inert gas to form a plasma, and the positive ions in this plasma collide with the surface of the target (negative electrode) to knock out the atoms forming the uniform getter, and this jumps out. The atoms are attached to the opposite substrate surface to form a film.

Conventionally, since the protective layer is required to have transparency and heat resistance in the visible light range, sputtering is performed using a ceramic target such as Z n S 1 S i 0 _2, or the like. Some thin film is formed. However, these materials can not be deposited by a DC sputtering system because the bulk resistance of the target is high, and a high frequency sputtering (RF) system is usually used.

However, this high frequency sputtering (RF) apparatus is not only expensive in itself but also has poor sputtering efficiency, high power consumption, complicated control, and many drawbacks such as slow deposition rate. is there. In addition, there is a problem that when high power is applied to increase the deposition rate, the temperature of the substrate rises, causing deformation of the polycarbonate substrate. Further, the zinc sulfide - Kei oxide (ZnS- S i 0 ₂₎ S I_〇 ₂ that is used to target for an average particle size in a conventional 4N or more high purity of 0.1 to 20 0 used It is manufactured by sintering at 700 to 1200 ° C.

However, not occur deformation of the S I_〇 ₂ itself in such a temperature range, for not occur even react with Zn S, tend to cause gaps between the Z n S and S I_〇 _2, also S i The finer the O ₂ , the more remarkable it becomes, and the densification of Z n S is also inhibited, resulting in a problem that the yield density decreases.

Furthermore, a target containing S i 0 ₂ in Z n S is likely to cause cracking when forming a film by sputtering, which may cause particles (dusting) to be generated during sputtering. Not only are nodules generated, the uniformity and quality of the film formation are degraded, but also the productivity is inferior.

The conventional optical disk protective film, ZnO, a main component one or more I n ₂ 〇 ₃ or Z n0 _2, A 1 ₂ 0 ₃ and or G a ₂ 〇 ₃ 0. lw t% or more 20 wt% It contains the following, Z R_〇 containing ₂ and or T i 0 ₂ to 0. 01 wt% or more 5w t% or less, to improve the uniformity of the coating, low reflectance, light having a high permeability in the visible region A disk protective film is disclosed (see, for example, Patent Document 1).

Further, ZnS-S I_〇 ₂ - disc protective film-shaped sputtering target for formation of a three-component material Z Itashita is disclosed (for example, see Patent Document 2). Furthermore, Nb ₂ 〇 _{_{_{3, V 2 0 5, B}}} 2 〇 _3, S I_〇 _{_2,} P ₂ 0 ₅ glass-forming oxide on selected one or more kinds from the 0. 01- 20% by weight A 1 ₂ 0 ₃ or Ga ₂ 0 ₃ 0. 0 1 contains one 20 wt%, the balance I n ₂ 〇 _3, Sn_〇 _2, the light-transmitting film which is an oxide on 1 or more kinds selected from Z n O A sputtering sputtering system for formation is disclosed (see, for example, Patent Document 3).

Patent Document 1 Japanese Patent Laid-Open No. 2000-1 95101

Patent Document 2 Japanese Patent Application Laid-Open No. 2001-0 11615

Patent Document 3 Japanese Patent Laid-Open No. 2000-1 19062 Disclosure of the invention

In the present invention, when forming a film by sputtering, the influence of heating on the substrate can be reduced, high-speed film formation can be performed, the film thickness can be adjusted thin, and particles generated during sputtering (dust generation) Sulfides with high density of 90% or more, particularly 95% or more, or even 98% or more, which can reduce mass variation and improve mass productivity. It is an object of the present invention to obtain a sputtering target containing zinc as a main component and an optical recording medium having a phase change optical disc protective film containing zinc sulfide as a main component using the target.

In order to solve the above-mentioned problems, as a result of intensive researches, the present inventors have reduced the bulk resistance value by using conductive oxides and nitrides as additives to the target, thereby reducing DC spark. We found that it was possible to make an evening ring, not impair the properties as a protective film, and further reduce the particles and nodules generated during sputtering, and also improve the film thickness uniformity.

The present invention is based on this finding.

1. Sputtering target characterized by containing zinc sulfide as a main component and containing conductive oxide and nitride, and phase change optical disc protective film containing zinc sulfide as a main component using the target Optical recording medium formed

2. The sputtering evening getter according to the above 1 according to the above 1 characterized in that the refractive index of the sputter film is from 2.0 to 2.6 at a wavelength of 300 to 700 nm, and sulfided using the target. Optical recording medium having a phase change optical disc protective film comprising zinc as a main component

3. Sputtering targets according to the above 1 or 2, characterized in that 0.1.lmo 1 to 4 Omo 1% of nitride is contained, and phase change type containing zinc sulfide as a main component using the target. Optical recording medium having an optical disc protective film formed thereon

4. The nitride is a nitride of one or more elements selected from titanium, tungsten, molybdenum, tantalum, aluminum, silicon, gallium, germanium, zirconium, chromium, niobium, hafnium and vanadium. An optical recording medium in which a zinc sulfide-based phase change optical disc protective film is formed using the sputtering set and the target described in each of 1 to 3 5. The total amount of the conductive oxide and the nitride is 20% or more by volume ratio, and the sputtering set as described in each of the above items 1 to 4 and the single set are used. Recording medium having a phase change optical disc protective film mainly composed of zinc sulfide

6. The sputtering set and the getter described in each of the above 1 to 5, wherein the conductive oxide is an oxide of one or more elements selected from indium, tin and zinc. Optical recording medium using zinc sulfide as a main component to form a phase change optical disc protective film

7. The sputtering target according to each of 1 to 6, characterized in that it further contains an oxide of one or more elements selected from Ge, Al, Gallium, Zirconium, Ge, antimony, Niobium. An optical recording medium having a zinc sulfide-based phase change optical disc protective film formed by using a weir and a jacket according to the present invention.

8. An oxide of one or more elements selected from Ge, aluminum, gallium, zirconium, germanium, antimony, niobium, in a weight ratio conversion of the element to the conductive oxide, 0.1 to 4 An optical recording medium comprising a sputtering target according to any of the above 1 to 7 containing 0%, and a phase change optical disc protective film comprising zinc sulfide as a main component, using the target.

9. Glass-forming oxide mainly composed of silica containing at least 0.1% by weight of one or more elements selected from aluminum, boron, phosphorus, alkali metals and alkaline earth metals in weight ratio to silicon oxide Recording using the sputtering target described in each of the above items 1 to 8 characterized in that a zinc sulfide is used and the phase change type optical disc protective film comprising zinc sulfide as a main component is formed. Medium

10. The sputtering target according to the above 9 characterized by containing 1 to 30% of a glass forming oxide in terms of molar ratio relative to the total amount and the phase change type containing zinc sulfide as a main component using the target Optical recording medium having an optical disc protective film formed thereon 1 1. Sputtering go as described in each of the above 1 to 10 characterized in that the average crystal grain size of the insulating phase or the high resistance phase present in the bulk is 5 / m or less. An optical recording medium having a zinc sulfide-based phase change optical disc protective film formed by using such a target

1 2. The insulating phase or high-resistance phase present in the target bulk contains at least one of zinc sulfide, silicon oxide, boron oxide, phosphorus oxide, alkali metal oxide, alkaline earth metal oxide An optical recording medium having a phase change type optical disk protective film comprising zinc sulfide as a main component by using the sputtering ring described in each of the above 1 to 11 and the target.

1 3. The sputtering target as described in each of the above 1 to 12 characterized in that the relative density is 90% or more, and the phase change optical disc protection comprising zinc sulfide as a main component using the same. Optical recording medium formed with film

1 4 Sputtering targets described in each of the above 1 to 13 characterized in that the bulk resistance value is 5 × 10 ² Ω cm or less, and zinc sulfide as the main component using the target Recording medium having a phase change optical disc protective film formed thereon

1 5. The sputtering target according to the above 14 and the sulfide used in the sputtering are characterized in that the variation of the bulk resistance value in the target is within ± 20% of the average value. Optical recording medium having a phase change optical disc protective film mainly composed of zinc

1 6. A zinc sulfide-based phase change optical disc protective film was formed using the duvets according to the above 1 to 15 characterized in that the sputter film is present in a stable amorphous state. Optical recording medium

I will provide a. Embodiment of the Invention

The sputtering target of the present invention contains zinc sulfide as a main component, and further contains a conductive oxide and a nitride. Yotsute thereto, usually with the characteristics as equivalent protection film and that ZnS-S I_〇 ₂ is used, it is possible to obtain a sputtering target Chikaratsu bulk resistance value is below 5 X 10_ ² Q cm , DC sputtering is possible. It is desirable that the variation in bulk resistance within the target be within ± 20% of the average value. As a result, it is possible to form a phase change type optical disc protective film mainly composed of zinc sulfide having uniform properties.

DC sputtering has the excellent features of faster deposition rate and better sputtering efficiency than the above-mentioned RF sputtering. In addition, the DC sputtering system is advantageous in that it is inexpensive, easy to control, and consumes less power.

The refractive index of the sputtered film is 2.0 to 2. 6 at a wavelength of 300 to 700 nm, preferably 380 to 450 m. As described above, by making the refractive index larger than the normal Z n S-S i O ₂ (2.0 to 2.1), it is also possible to reduce the thickness of the protective film itself. It can improve and prevent the substrate heating.

Therefore, by using the sputtering target of the present invention, productivity can be improved, a material with excellent quality can be obtained, and a remarkable effect of stably manufacturing an optical recording medium having an optical disc protective film at low cost can be obtained. There is.

The metal nitride in the sputtering target preferably contains 0.1 to 40 mol%. In addition, it is desirable that the total amount of the conductive oxide and the nitride be 20% or more, and more preferably 25% or more in volume ratio. These are to obtain the necessary conductivity, maintain the stable amorphousness of the sputtering film, and maintain the characteristics of ZnS itself.

Can not exhibit the effect of addition of a nitride content of 0. lmo less than 1%, 4 with the Omo exceeds 1%, the effect is saturated, the conventional ZnS-S I_〇 problem ₂ film greatly characteristics differ is It is because it occurs. Preferably, it is 1 to 2 Omo 1%. In addition, if the total amount of the conductive oxide and the nitride is less than 20% by volume ratio, the bulk resistance value can not be effectively reduced, and the amorphous stability is poor. It is from. Further, the upper limit value of the total amount of conductive oxide and nitride is set to 7 0 V o 1%. Moreover, a preferable range is 25 to 35% by volume ratio.

As the nitride, a nitride of at least one metal selected from titanium, tungsten, molybdenum, tantalum, aluminum, silicon, gallium, germanium, zirconium, chromium, niobium, hafnium, and vanadium is used. This adjusts the conductivity, refractive index, thermal conductivity, and amorphous.

Also, the conductive oxide is selected from oxides of indium, tin and zinc. Furthermore, an oxide of one or more elements selected from aluminum, gallium, zirconium, germanium, antimony, and niobium can be further contained. This content is an element relative to the conductive oxide. It is desirable to contain 0.1 to 40% in terms of weight ratio of.

The reason for the inclusion of the oxide is that the conductive oxide and the oxide different in valence are dissolved to form an unstability, whereby the number of conduction electron holes can be increased. It is for obtaining a stable amorphous property. In this case, in particular, it is desirable to dissolve the oxide in advance before mixing with Z n S.

The lower limit of the conductive oxide when converted to a weight ratio of 0.01 to 40% is to obtain the effect of the addition, and the upper limit is more than the solid solution limit. If this is the case, the conductivity will be inhibited or the influence on film amorphousness can not be neglected. _C Furthermore, the sputtering target of the present invention can be made to contain oxidized silicon. The inclusion of silica oxide has the advantage that the optical properties, thermal conductivity, amorphousness, etc. can be adjusted to be equivalent to Z n S 1 S i 0 ₂ .

Inclusion of silica oxide has the disadvantage of being a starting point of abnormal discharge in direct current sputtering, but the weight of one or more selected from aluminum, boron, phosphorus, alkali metals and alkaline earth metals with respect to silicon oxide By containing the glass forming key oxide having a ratio of 0.01% or more, the above-mentioned defects can be eliminated, and therefore, the above-mentioned optical characteristics, thermal conductivity, amorphousness, etc. It is effective to add keoxide which has the effect that it can be adjusted to i 0 ₂ equivalently. In addition, it is desirable that the glass forming oxide is contained in an amount of 1 to 30% in terms of molar ratio to the total amount. This makes it possible to obtain a film equivalent to Z n S-S i 0 ₂ without abnormal discharge.

The average grain size of the insulating phase or high-resistance phase present in the bulk of the target is preferably 5 m or less, and the insulating phase or high-resistance phase present in the bulk of the singlet is zinc sulfide, oxidized It is desirable to contain one or more of silica, boron oxide, phosphorus oxide, alkali metal oxide, and alkaline earth metal oxide. By this, the effect of suppressing abnormal discharge can be obtained.

Furthermore, it is possible to obtain high density of relative density of 90% or more, further 95% or more of the present invention. As a result, particles (dust generation) and nodules can be further reduced during sputtering, and variations in quality can be reduced to improve mass productivity.

In the method of manufacturing the sputtering target of the present invention, raw material powders such as zinc sulfide are uniformly mixed, heated to a temperature of 800 to 130 ° C. by a hot press or a hot isostatic press, and a surface pressure Sinter under conditions of 100 kg Z cm ² or more.

As a result, the main component is zinc sulfide having a relative density of 90% or more, a relative density of 95% or more, and a bulk resistance value of 5 × 10 ² Ω cm or less according to the four-terminal method. Sputtering targets can be manufactured. The bulk resistance value in this specification is based on the same measurement method.

The density of the sputtering target containing zinc sulfide as a main component of the present invention can be improved by reducing the pores and refining the crystal grains, and making the sputtering surface of the surface uniform and smooth. It has the remarkable effect of reducing particles and nodules and also prolonging the get-life.

In addition, a sputtered film formed using the sputtering target crucible of the present invention exists in a stable amorphous form (that is, in a film after an annealing treatment of 300 ° C. or more, it is determined by XRD peak intensity measurement) It shows excellent film characteristics that the crystal phase can not be identified. Example and comparative example

Hereinafter, the present invention will be described based on Examples and Comparative Examples. The present embodiment is merely an example, and the present invention is not limited in any way. That is, the present invention is limited only by patent claims, and includes various modifications other than the embodiments included in the present invention.

(Example 1)

Purity 4N (99.99%) in which zinc sulfide (Z n S) powder, purity of 4N is a conductive oxide (99.99%) indium oxide (I n ₂ 〇 ₃₎ powder of 2 Omo 1% 1% of titanium nitride (TiN) 1 Omo was added and mixed uniformly.

The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1000 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 93%. In addition, the Balta resistance value was 2.5 × 10 0 ³ Ω cm (indicated as 2.5 E- ³ Q cm in the table, and so on).

A target is prepared from this bulk body, and a sputtering test is performed. DC sputtering can be easily performed, and a conductive oxide-containing phase change optical disc protective film having high density Z n S as a main component with excellent characteristics can be formed. A sputtering target was obtained.

The refractive index was 2.2 and the film quality was amorphous (after annealing).

The refractive index is a measured value at a wavelength of 405 nm. A sample of 6 inches in size is prepared and sputtered under conditions of Ar pressure 0.5 Pa, Ar flow 100 sccm, power 100 OW, The film was formed to a thickness of 1 500 A (the following examples and comparative examples were performed under the same conditions).

(Example 2)

The purity 4N zinc sulfide is (99. 99%) (Z n S) powder, indium oxide which is a conductive oxide having a purity of 4N (99. 99%) (I n 2 0 3) powder 30mo l%, nitrogen Zirconium fluoride (ZrN) 1 Omo 1% was added and mixed uniformly. The mixed powder was filled in a graphite die and subjected to hot pressing under conditions of a surface pressure of 200 kg / cm ² and a temperature of 1100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 90%. Also, the bulk resistance value was 1.2 × 10 ³ Ω cm.

A target is prepared from this bulk body, and a spatter test is performed. DC spattering can be easily performed, and a conductive oxide-containing phase change type optical disc protective film having a high density Z n S as a main component with excellent characteristics. A sputtering target for formation was obtained. The refractive index was 2.3 and the film quality was amorphous (after annealing).

(Example 3)

The purity 4N zinc sulfide is (99.99%) (Z n S) powder, purity 4 N oxide Injiumu (I n ₂ 0 ₃₎ of (99.99%) flour 20Mo l%, chromium nitride (C r ₂ N) 1 Omo 1% was added and mixed uniformly.

The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1000 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 98%. Also, the bulk resistance value was 1.4 × 10 0 ^-3 Ω cm.

When a target is produced from this bulk body and a sputtering test is carried out, DC sputtering can be easily performed, and a sputtering target for forming a phase change optical disc protective film having high density Z n S as a main component with excellent characteristics can be obtained. It was done. The refractive index was 2.4, and the film quality was amorphous (after annealing).

(Example 4)

Purity 4N (99. 99%) a a zinc sulfide (ZnS) powder, oxide Injiumu (I n ₂ 〇 ₃₎ purity of 4N (99. 99%) flour 20Mo l%, purity 4N (99. 9 9%) 10 mol% of SiO _{2 and} 1% of tantalum nitride (TaN) 1 Omo were added and uniformly mixed.

The mixed powder was filled in a graphite die and hot pressed under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1000 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 91%. Also, the bulk resistance value was ^2.5 × 10 ² ohm-cm. When a target is produced from this bulk body and a sputtering test is performed, DC sputtering can be easily performed, and a sputtering target for forming a phase change type optical disc protective film mainly composed of high density Z n S with excellent characteristics is formed. A bribe was obtained. The refractive index was 2.1, and the film quality was amorphous (after annealing).

(Example 5)

Purity 4N (99. 99%) a a zinc sulfide (Z n S) flour, I TO purity 4N (99. 99%) (I n 2 0 3 - 1 Ow t% S n0 2) powder of 1 5MO 1%, purity 4 N (99. 99%) S i 0 ₂ 5 mo 1%, titanium nitride (T i N) 20 mol% were added and uniformly mixed.

The mixed powder was filled in a graphite die, and hot pressed under conditions of a surface pressure of 200 kg / cm ² and a temperature of 1 100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 90%. Moreover, the bulk resistance value 2. was ² X 1 0- 2 Qcm.

A target plate was prepared from this bulk body, and a sputtering test was carried out. DC sputtering can be easily performed, and a conductive oxide-containing phase change optical disc protective film having high density Z n S as a main component with excellent characteristics. A sputtering target for formation was obtained. The refractive index was 2.4, and the film quality was amorphous (after annealing).

(Example 6)

Purity 4N zinc sulfide is (99. 99%) (Z n S) flour, I TO purity 4N (99. 99%) (I n 2 0 3 - 10 wt% S n 0 2) powder of 20Mo l %, 1% nitrided niobium (NbN) 1 Omo were added and mixed uniformly.

The mixed powder was filled in a graphite die, and hot pressed under conditions of a surface pressure of 200 kg / cm ² and a temperature of 1 100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 95%. Also, the bulk resistance value was 8.5 × 10 0 ^-3 Ω cm.

When a single get is produced from this bulk body and a sputtering test is carried out, DC sputtering can be easily performed, and a conductive oxide-containing phase change type optical disc protective film having high density Z n S as a main component with excellent characteristics. A sputtering target for formation was obtained. The refractive index was 2.3 and the film quality was amorphous (after annealing). (Example Ί)

Zinc sulfide (Z n S) powder with a purity of 4% (99. 99%), GZO (Ζ θθ-2 wt% G a ₂ 0 ₃ ) powder of purity 4% (99. 99%), 20mo 1%, nitrided 10 mol% of zirconium (ZrN) was added and mixed uniformly.

The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 90%. Also, the bulk resistance value was 1.5 × 1 (T ³ Qcm.

A vacuum was prepared from this bulk body, and a sputtering test was conducted. DC sputtering could be easily performed, and a conductive oxide-containing phase change optical disc protective film mainly composed of a high density Z n S having excellent characteristics Sputtering for forming was obtained. The refractive index was 2.4, and the film quality was amorphous (after annealing).

(Example 8)

Zinc sulfide (Z n S) powder with a purity of 4N (99. 99%), GZO (ZnO-2 wt% Ga ₂ 0 ₃ ) powder with a purity of 4 N (99. 99%) 10 mol%, Nitrided 1% of titanium (TiN) 3 Omo was added and mixed uniformly.

The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg Z cm ² and a temperature of 1100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 96%. Moreover, the bulk resistance value was 3. 0 X 1 0- ³ Qcm.

The target is fabricated from this bulk body and the sputtering test is carried out. DC sputtering can be easily performed, and high-density Z n S-based conductive oxide-containing phase change optical disc protective film can be formed with excellent characteristics. A sputtering target was obtained. The refractive index was 2.4, and the film quality was amorphous (after annealing).

(Example 9)

The purity 4N zinc sulfide is (99. 99%) (Z n S) flour, I ZO purity 4N (99. 99%) (I n 2 0 3 - 1 0 wt% Ζ ηθ) powder 20Mo l%, ₅ mol% of silicon nitride (Si ₃ N ₄ ) was added and mixed uniformly. The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1 100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 92%. In addition, the bulk resistance value was 1.4 × 1 (Γ ³ Ω cm).

The target is fabricated from this bulk body and the sputtering test is carried out. DC sputtering can be easily performed, and high-density Z n S-based conductive oxide-containing phase change optical disc protective film can be formed with excellent characteristics. A sputtering target was obtained. The refractive index was 2.2 and the film quality was amorphous (after annealing).

(Example 10)

Purity 4N (99. 99%) a a zinc sulfide (Z n S) powder, oxide Injiumu (I n ₂ 0 ₃₎ having a purity of 4N (99. 99%) flour 20Mo l%, silicate glass (S i 0 ₂ —0.2 wt% A 1 ₂ 0 ₃ − 0. 1 wt% N a ₂ 0 ₃ ) 1 Omo 1 aluminum nitride (A 1 N) 5 mol% was added and uniformly mixed.

The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1 000 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 91%. Moreover, the bulk resistance value 2. was 3 X 1 0- ² Ω cm.

A target is prepared from this bulk body, and a sputtering test is carried out. DC sputtering can be easily performed, and sputtering with a high density Z n S having excellent characteristics as a main component for forming a protective film for a phase change optical disc is performed. A bribe was obtained. The refractive index was 2.2 and the film quality was amorphous (after annealing).

(Example 1 1)

Purity 4N (99. 99%) a a zinc sulfide (Zn S) powder, oxide Injiumu (I n ₂ 0 ₃₎ having a purity of 4N (99. 99%) flour 20Mo l%, silicate glass (S i 0 ₂ one _{0. 2 wt% a 1 2 0} 3 - 0. 1 wt% N a 2 0 3) 1 0mo l%, nitride Germa Niumukuromu (Ge C rN) was added 1 Omo 1%, and homogeneously mixed. 2003/009996

1 5 The mixed powder was filled in a graphite die and hot pressed under the conditions of a surface pressure of 200 kg Zcm ² and a temperature of 1000 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 94%. Also, the bulk resistance value was 1.2 × 10 ² Ω cm.

When a getter was produced from this bulk body and a sputtering test was conducted, DC sputtering could be easily carried out, and sputtering with a high density Z n S of excellent characteristics, such as a sputtering for forming a phase change optical disc protective film, was made. The target was obtained. The refractive index was 2.3 and the film quality was amorphous (after annealing).

(Comparative example 1)

Zinc sulfide (Z n S) powder with a purity of 4N (99. 99%), with a powder of zinc oxide (I n ₂ 0 ₃ ) with a purity of 4N (99. 9 9%) 1 Omo 1%, titanium nitride (Ti N) 0. 05mo 1% was added and mixed uniformly.

The mixed powder was filled in a graphite die, and hot pressed under conditions of a surface pressure of 200 kg / cm ² and a temperature of 1 100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 98%. Also, the bulk resistance value was 2.0 Ω cm.

A target was fabricated from this bulk body, and when a sputtering test was conducted, abnormal discharge occurred during DC sputtering. Due to these factors, particles and dust increased. As described above, under the conditions of Comparative Example 1, not only the uniformity and quality of the film formation were degraded, but also there was a problem that the productivity was inferior.

Z nS-I n ₂ 0 ₃ -T i N A phase-change type optical disc protective film was not suitable as a sputtering set for forming a protective film. The refractive index was 2.2 and the film quality was crystalline (after annealing).

(Comparative example 2)

Purity 4N (99. 99%) a a zinc sulfide (Zn S) powder, purity 4N (99. 99%) of the oxide Injiumu (I n ₂ 0 ₃₎ powder 1 0 mo 1%, zirconium nitride (Z r N 0. 01 mo 1% was added and mixed uniformly. The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg / cm ² and a temperature of 1 100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 95%. In addition, the bulk resistance value is 1.4Ω. There are 7 at m.

When a target was produced from this bulk body and a spatter test was conducted, abnormal discharge occurred during DC sputtering. Due to these factors, particles and dust increased. As described above, under the conditions of Comparative Example 1, not only the uniformity and quality of the film formation were degraded, but also there was a problem that the productivity was inferior.

Z n S-I n ₂ 0 ₃ -Z r N A phase change type optical disc protective film was not suitable as a sputtering set for forming a protective film. The refractive index was 2.3, and the film quality was crystalline (after annealing).

(Comparative example 3)

Zinc sulfide (Z n S) powder having a purity of 4N (99. 99%) was added to a purity of 4N (99. 99%).

I TO (I n ₂ of _{99%) 0 3 - 10 wt} % S n 0 2) powder of 1 Omo 1%, purity 4

₂₀ mol% of titanium oxide (S i 0 ₂ ) of N and 0.5% of 1% of tantalum nitride (TaN) were added and uniformly mixed.

The mixed powder was filled in a graphite die and subjected to hot pressing under the conditions of a surface pressure of 200 kg Zcm ² and a temperature of 1 100 ° C. in a vacuum atmosphere. The relative density of the bulk obtained by this was 90%. Also, the bulk resistance value is 1.0 x 1

It was more than 0 ² Ω cm.

A target was fabricated from this bulk body, and a spatter test was conducted. An abnormal discharge occurred during DC sputtering. Due to these factors, particles and dust increased. As described above, under the conditions of Comparative Example 1, there is a problem that not only the uniformity and quality of the film formation is degraded, but also the productivity is inferior.

Z n S-I TO-S i 0 _2- A sputtering target for forming a TaN phase change optical disc protective film was not suitable. The refractive index was 2.2, and the film quality was crystalline (after photosynthesis). The compositions and characteristic values of the above Examples 1 to 1 and Comparative Examples 1 to 3 are shown in Table 1. As shown in the above example, by containing zinc sulfide as a main component, and containing a conductive oxide and a predetermined amount of nitride in this, the bulk resistance value can be lowered and DC sputtering becomes possible, and the characteristics as a protective film It was also found that it has the effect of being able to reduce particle / nodules generated at the time of sputtering and also to improve the film thickness uniformity without any loss.

Although Examples 1 to 8 above show representative examples of the target composition of the present invention, similar results were obtained with other target compositions included in the present invention.

On the other hand, in Comparative Examples 1 to 3, although the nitride is added, the amount is insufficient and the bulk resistance value becomes high, and an abnormal discharge occurs at the time of sputtering, and As a result, it has been found that there is a problem that particles (dust generation) and nodules increase and that the characteristics as a phase change optical disc protective film are also impaired.

From the above, it can be seen that the sputtering target having zinc sulfide as a main component of the present invention is extremely effective as a target for forming a phase change type light protection film.

Although not particularly shown in the examples, similar results are obtained when one or more oxides selected from aluminum oxide, gallium oxide, zinc oxide, germanium oxide, antimony oxide and niobium oxide are contained. It was done.

table 1

Glass forming transition metal fife; f3⁄4i -ffP ,,

Example i ⁷ g film oxide oxide P IHU (mer = ΙΒΟΙΛ = mo moiJ mol% Ω cm.) Conducted 1 70 70 _{2 2} 0 ₃ 0 TiN 93 2.5E-03 DC acceptable 2.2 amorphous

20 10

Conducted 2 60 Ι 0 ₂ 0 ₃ 0 ZrN 90 L2E-03 DC Allowed 2.3 Amorphous

30 10

Conducted 3 80 Ι 0 ₂ 0 ₃ 0 Cr ₂ N 98 1.4E-03 DC Allowed 2.4 Amorphous

20 10

Conducted 4 60 1 η ₂ 0 ₃ Pure Si 0 ₂ TaN 91 2.5E-02 DC Allowed 2.1 Amorphous

20 10 10

Conducted 5 60% pure Si0 ₂ TiN 90 2.2E-02 DC 1 2.4 ^ 3⁄4 quality

15 5 20

Implementation 6 70 [TO 0 NbN 95 8.5E-03 DC Allowed 2.3 Amorphous

20 10

Conducted 7 70 GZO 0 ZrN 90 1.5E-03 DC Allowed 2.4 Amorphous

20 10

Conducted 8 60 GZO 0 TiN 96 3.0E-03 DC Allowed 2.4 Amorphous

30

Implementation 9 75 (ΖΟ 0 Si3N4 92 1.4E-03 DC acceptable 2.2 3⁄4 "ΘΒ 莨

20 5

Implementation 10 65 In ₂ 0 ₃ Silicate glass A1N 91 2.3E-02 DC Allowed 2.2 Amorphous

20 10 5

Conducted 11 60 Ι ₂ 0 ₃ Silica glass GeCrN 94 1.2E-02 DC acceptable 2.3 Amorphous

20 10 10

Comparison 1 89 Ι η ₂ 0 ₃ 0 TiN 98 2.0E-00 anomalous discharge 2.2 crystalline

10 0.05

Comparison 2 88 Ι 0 ₂ 0 ₃ 0 ZrN 95 1.4E- 00 anomalous discharge 2.3 crystalline quality

10 0.01

Comparison 3 68ΙΤΟ Pure Si0 ₂ TaN 90> 1.0 E + 02 abnormal discharge 2.2 Amorphous

10 20 0.05

ΙΤΟ is in ₂ 0 ₃ - shows the K) t% Sn0 ₂ GZO is _{_{ZnO-2wt% Ga 2 0 3}} IZO is In ₂ 0 ₃ -10wt% ZnO. Silicate glass _{_{S i0 2 -0. 2wt¾Al 2 0}} 3 -Q. Lwt¾Na 2 03 Effect of the invention

The present invention enables significant DC sputtering when forming a film by sputtering, which is a feature of DC sputtering, is easy to control, can increase the deposition rate, and can improve the sputtering efficiency. There is. In addition, since it is possible to increase the refractive index, productivity is improved by using this sputtering target, and it is possible to obtain an excellent quality material in which the film quality is amorphous and stable. There is a significant effect that an optical recording medium having a protective film can be stably manufactured at low cost.

Furthermore, particles (dust generation) and nodules generated during sputtering can be reduced, the variation in quality can be reduced, mass productivity can be improved, and the number of holes is small, the crystal grains are fine, and the bulk resistance value is 5 X 1 0 ² Ω cm or less, a zinc sulfide having a high density on the relative density of 90% or more can you to produce sputtering evening Getto mainly, also without compromising the characteristics as a protective film, the It has a remarkable effect that it is possible to obtain an optical recording medium on which a phase change optical disc protective film composed mainly of zinc sulfide is formed by using a target.

Claims

Scope of request 1. Sputtering target characterized by containing zinc sulfide as a main component and containing conductive oxide and nitride, and phase containing zinc sulfide as a main component using such a target. Optical recording medium having a changeable optical disc protective film formed thereon.

2. The sputtering target according to claim 1, wherein the refractive index of the sputter film is from 2.0 to 2.6 at a wavelength of 300 to 700 nm. An optical recording medium using zinc sulfide as the main component to form a phase change optical disc protective film.

3. A sputtering target according to claim 1 or 2 characterized in that it contains 0.lmo 1 to 4 Omo 1% of nitride and zinc sulfide as a main component using said target. An optical recording medium having a phase change optical disc protective film formed thereon.

4. The nitride is a nitride of at least one metal selected from titanium, tungsten, molybdenum, tantalum, aluminum, silicon, gallium, germanium, zirconium, chromium, niobium, hafnium and vanadium. An optical recording medium comprising a sputtering target according to any one of the items 1 to 3 and a phase change optical disc protective film comprising zinc sulfide as a main component using the sputtering target.

5. The sputtering target according to any one of claims 1 to 4 and the target according to any one of items 1 to 4 characterized in that the total amount of conductive oxide and nitride is 20% or more by volume ratio. 5. An optical recording medium using zinc sulfide as a main component to form a phase change optical disc protective film.

6. The sputtering ring set according to any one of claims 1 to 5, wherein the conductive oxide is an oxide of one or more elements selected from indium, tin and zinc. And an optical recording medium having a zinc sulfide-based phase change optical disc protective film formed by using the target.

7. An oxide according to any one of claims 1 to 6, characterized in that it further contains an oxide of one or more elements selected from calcium, aluminum, gallium, zirconium, germanium, antimony and niobium. An optical recording medium in which a phase change optical disc protective film comprising zinc sulfide as a main component is formed using the sputtering set forth above and the target.

8. An oxide of one or more elements selected from silicon, aluminum, gallium, zirconium, germanium, antimony and niobium in a weight ratio conversion of the element to the conductive oxide of 0.1 to 0.1. The sputtering target according to any one of claims 1 to 7, which contains 40%, and a phase change optical disc protective film comprising zinc sulfide as a main component using the target. An optical recording medium formed.

9. Glass-forming oxide mainly composed of silica containing at least 0.1% by weight of one or more elements selected from aluminum, boron, phosphorus, alkali metals and alkaline earth metals in weight ratio to silicon oxide 9. The sputtering target according to any one of claims 1 to 8 characterized in that the phase change optical disc protective film comprising zinc sulfide as a main component is prepared by using the sputtering target according to any one of claims 1 to 8. Optical recording medium formed.

10. Sputtering target according to claim 9, characterized in that the glass-forming oxide is contained in an amount of 1 to 30% in terms of molar ratio to the total amount, and zinc sulfide is used as the main component using said sputtering. An optical recording medium having a phase change optical disc protective film formed thereon.

11. The sputtering electrode according to any one of items 1 to 10, wherein the average crystal grain size of the insulating phase or high-resistance phase present in the target bulk is 5 / m or less. And an optical recording medium having a zinc sulfide-based phase change optical disc protective film formed using the target.

1 2 Insulating phase or high-resistance phase existing in the target bulk Containing at least one of zinc sulfide, zinc oxide, boron oxide, phosphorus oxide, alkali metal oxide, alkaline earth metal oxide An optical recording medium comprising a sputtering target according to any one of claims 1 to 11 and a phase change optical disc protective film comprising zinc sulfide as a main component using said target.

1 3. The sputtering target according to any one of items 1 to 12 characterized in that the relative density is 90% or more, and zinc sulfide as a main component using the target. An optical recording medium having a phase change optical disc protective film formed thereon.

1 4. A sputtering sunset according to any one of claims 1 to 13, characterized in that the bulk resistance value is 5 × 10 ² Ω cm or less An optical recording medium having a phase change optical disc protective film comprising zinc sulfide as a main component.

15. The sputtering target and the target according to claim 14, wherein the dispersion of the bulk resistance value in the target is within ± 20% of the average value. An optical recording medium having a phase change optical disc protective film comprising zinc sulfide as a main component.

6 6. A phase change optical diode based on zinc sulfide using the target according to any one of claims 1 to 15, characterized in that the sputter film is present in a stable amorphous state. Optical recording medium with a protective film formed on it.