JPWO2013145818A1 - Sputtering target and manufacturing method thereof - Google Patents

Abstract

The content of Al is 0.2 to 3.0 mol% in terms of Al2O3, the content of Mg and / or Si is 1 to 27 mol% in terms of MgO and / or SiO2, and the balance is the content of ZnO in terms of ZnO A sputtering target comprising 0.1 to 20 wt% of a metal that forms a low melting point oxide having a melting point of 1000 to C or less in terms of oxide weight with respect to the basic composition. Provided is a target for forming an optical thin film that does not contain sulfur, has a low bulk resistance, can be DC-sputtered, and has a low refractive index, and a method for manufacturing the same. Since the target itself has a high density, there is little abnormal discharge and stable sputtering is possible. Furthermore, since the thin film formed by sputtering has a high transmittance and is composed of a non-sulfide system, it is useful for forming a thin film for an optical information recording medium in which the adjacent reflective layer and recording layer are unlikely to deteriorate. Through the improvement of the characteristics of the optical information recording medium, the reduction of the equipment cost, and the improvement of the film forming speed, the throughput is greatly improved.

Description

  The present invention relates to a target for forming an optical thin film that does not contain sulfur, has low bulk resistance, can be DC-sputtered, and has a low refractive index, and a method for manufacturing the same.

Conventionally, ZnS-SiO generally used mainly for a protective layer of a phase change type optical information recording medium ₂Has excellent characteristics in optical characteristics, thermal characteristics, adhesion to the recording layer, and the like, and is widely used. However, rewritable optical discs represented by Blu-Ray are now strongly required to increase the number of rewrites, increase the capacity, and increase the recording speed.

One of the causes of deterioration of the number of rewrites and the like of the optical information recording medium is diffusion of the sulfur component from ZnS—SiO ₂ to the recording layer material arranged so as to be sandwiched between the protective layers ZnS—SiO _2. . In addition, pure Ag or an Ag alloy having high reflectivity and high thermal conductivity has been used for the reflective layer material in order to increase the capacity and increase the recording speed. Such a reflective layer is also a protective layer material. They are arranged in contact with the ZnS-SiO _2.
Accordingly, in this case as well, due to the diffusion of the sulfur component from ZnS—SiO ₂ , the pure Ag or Ag alloy reflective layer material also corrodes and becomes a factor that causes the characteristics such as the reflectance of the optical information recording medium to deteriorate. It was.

In order to prevent diffusion of these sulfur components, an intermediate layer mainly composed of nitride or carbide is provided between the reflective layer and the protective layer and between the recording layer and the protective layer. However, this causes an increase in the number of layers, resulting in a problem that throughput decreases and costs increase. To solve the above problems, replaced with the material of the oxide only free of sulfide in the protective layer material, ZnS-SiO ₂ equivalent or more optical properties, material system having an amorphous stability study Has been.

ZnS-SiO₂Since ceramic targets such as these have a high bulk resistance value, they cannot be formed by a direct current sputtering apparatus, and usually a high frequency sputtering (RF) apparatus is used.
However, this high-frequency sputtering (RF) apparatus has not only an expensive apparatus itself, but also has a number of disadvantages such as poor sputtering efficiency, large power consumption, complicated control, and slow film formation speed. In addition, when high power is applied to increase the deposition rate, there is a problem that the substrate temperature rises and the polycarbonate substrate is deformed. ZnS-SiO ₂However, there is a problem that throughput is reduced and cost is increased due to the thick film thickness.

From the above, as a target capable of DC sputtering, a sintered body target has been proposed in which an element having a valence of positive trivalent or higher is added alone to ZnO (for example, see Patent Document 1). However, in this case, it is considered that it is not possible to achieve both a low bulk resistance value and a low refractive index.
Further, as a transparent conductive film and a sintered body for manufacturing the transparent conductive film, a manufacturing method by a high frequency or direct current magnetron sputtering method in which various group II, group III, and group IV elements are combined has been proposed (see Patent Document 2). ). However, the purpose of this technique is not aimed at reducing the resistance of the target, and it is considered impossible to achieve both a low bulk resistance value and a low refractive index.

Further, a ZnO sputtering target has been proposed under the condition that at least one element to be added is dissolved in ZnO (see Patent Document 3). Since this is a condition that the additive element is dissolved, there is a problem that the component composition is limited, and therefore the optical characteristics are also limited.

From the above, the present applicant has been able to solve the above problems at once by inventing the contents shown in Patent Document 4 below. That is, a sputtering target having a low refractive index and a low bulk resistance consisting of Al ₂ O ₃ : 0.2 to 3.0 at%, MgO and / or SiO ₂ : 1 to 27 at%, and the balance ZnO. By providing, the target and film formation characteristics could be greatly improved. However, one problem occurred here.
The target needs to be densified in order to perform stable sputtering. However, in the above component system, if the sintering temperature is increased for higher density, it is difficult to increase the density due to decomposition (evaporation) of ZnO. Therefore, low temperature sintering and high density have been required.

JP-A-2-14959 JP-A-8-264022 JP-A-11-322332 Japanese Patent No. 4828529

  The present invention maintains the characteristics of Patent Document 4, that is, does not contain sulfur, has low bulk resistance, can be DC-sputtered by appropriate selection of materials, and has a low refractive index target for forming an optical thin film and its production In addition to providing a method, a high density sputtering target is provided. Furthermore, the thin film for optical information recording media, which has excellent adhesion to the recording layer and mechanical properties, has high transmittance, and is composed of a non-sulfide system, makes it difficult for the adjacent reflective layer and recording layer to deteriorate. In particular, the present invention provides a sputtering target that is useful for forming a protective film and a method for producing the same. Accordingly, it is an object to greatly improve the throughput by improving the characteristics of the optical information recording medium, reducing the equipment cost, and increasing the film forming speed.

In order to solve the above-mentioned problems, the present inventors have conducted intensive research. As a result, the inventors have found that high density can be achieved by adding a metal that forms a low melting point oxide to Patent Document 4. Obtained. And, the optical characteristics and amorphous stability equivalent to those of ZnS-SiO ₂ are secured, high-speed film formation by DC (direct current) sputtering is possible, and RF sputtering can be carried out if necessary, It was found that the characteristics and productivity of optical information recording media can be improved.

The present invention is based on this finding,
1) Metal that forms a low-melting-point oxide with respect to a basic composition comprising three or four elements of zinc (Zn), aluminum (Al), magnesium (Mg) and / or silicon (Si), and oxygen (O) A target containing Al, wherein the Al content is Al₂O₃0.2 to 3.0 in terms of conversion
 mol%, Mg and / or Si content is MgO and / or SiO₂1 to 27 mol% in terms of conversion and the balance is a ZnO content of Zn, and the metal that forms a low melting point oxide having a melting point of 1000 ° C. or less is 0.1% in terms of oxide weight. Sputtering target characterized by containing ~ 20 wt%,
2) The sputtering target according to 1) above, wherein the content of the metal forming the low melting point oxide is 0.1 to 10 wt% in terms of oxide.
3) As a low melting point oxide, B₂O₃, P₂O₅, K₂O, V₂O₅, Sb₂O₃, TeO ₂, Ti₂O₃, PbO, Bi₂O₃, MoO₃The sputtering target according to 1) or 2) above, which is one or more materials selected from

4) Mg and / or Si sputtering target according to any one of the above 1) to 3), wherein the content of 10～27Mol% of MgO and / or SiO ₂ in terms of,
5) The sputtering target according to any one of 1) to 4) above, wherein the relative density is 98% or more,
6) The sputtering target according to any one of 1) to 5) above, wherein the target has a bulk resistance of 10 Ω · cm or less.
7) The above 1) to 6), which are used for an optical thin film for forming a protective layer, a reflective layer or a semi-transmissive layer of an optical information recording medium, for an organic EL television, for a touch panel electrode, and for a hard disk seed layer. ) Sputtering target according to any one of

8) Basic sintering so that the total amount of Al ₂ O ₃ powder is 0.2 to 3.0 mol%, MgO and / or SiO ₂ powder is 1 to 27 mol%, and the balance is ZnO powder, and the total amount thereof is 100 mol%. A raw material powder is prepared, and 0.1 to 20 wt% of a low melting point oxide powder having a melting point of 1000 ° C. or lower is further added thereto to obtain a sintered raw material. This sintered raw material exceeds 800 ° C. and 1150 ° C. A method of producing a sputtering target, characterized by hot pressing with less than
9) The method for producing a sputtering target according to 8) above, wherein the relative density is 98% or more,
10) The method for producing a sputtering target according to any one of 8) to 9) above, wherein the bulk resistance is 10 Ω · cm or less,
The sputtering target having the above can easily obtain a target having a relative density of 98% or more and a bulk resistance of 10 Ω · cm or less. It is useful as a target for forming a thin film used for an optical thin film for forming a protective layer, a reflective layer or a semi-transmissive layer of an optical information recording medium, for an organic EL television, for a touch panel electrode, and for a seed layer of a hard disk. is there.

The present invention further provides the following thin film formed using the above target. 11) Metal that forms a low-melting-point oxide with respect to a basic composition composed of three or four elements of zinc (Zn), aluminum (Al), magnesium (Mg) and / or silicon (Si), and oxygen (O) The content of Al is 0.2 to 3.0 mol% in terms of Al ₂ O ₃ , and the content of Mg and / or Si is 1 to 27 mol in terms of MgO and / or SiO _2. % Of the basic composition consisting of ZnO equivalent content of Zn, and further containing 0.1 to 20 wt% of metal forming a low melting point oxide having a melting point of 1000 ° C. or less in terms of oxide weight. A thin film, characterized by
12) The thin film according to 11) above, wherein the content of the metal forming the low melting point oxide is 0.1 to 10 wt% in terms of oxide,
13) low-melting-point _oxide, from _{B 2 O 3, P 2 O} 5, K 2 O, V 2 O 5, Sb 2 O 3, TeO 2, Ti 2 O 3, PbO, Bi 2 O 3, MoO 3 The thin film according to 11) or 12) above, wherein the thin film is one or more selected.
14) The thin film according to any one of 11) to 13) above, wherein the content of Mg and / or Si is 10 to 27 mol% in terms of MgO and / or SiO ₂ ;
15) The thin film according to any one of 11) to 14) above, wherein the refractive index (wavelength 550 nm) is 2 or less,
16) The thin film according to any one of 11) to 15) above, wherein the extinction coefficient (λ = 450 nm) is less than 0.01,
17) The above 11) to 16), which are used for an optical thin film for forming a protective layer, a reflective layer or a semi-transmissive layer of an optical information recording medium, an organic EL television, a touch panel electrode, and a hard disk seed layer. A thin film according to any one of the above.

By replacing the protective layer material ZnS—SiO ₂ with an oxide-only material that does not contain sulfide, the deterioration of the adjacent reflective layer, recording layer, and the like due to sulfur is suppressed and ZnS—SiO _{2 is used.} The optical characteristics are equal to or better than the above, and high-speed film formation is possible by reducing the bulk resistance value. Furthermore, since a high-density sputtering target can be provided, it is possible to reduce the occurrence of abnormal discharge and to achieve an excellent effect that stable sputtering is possible. Also useful for optical information recording medium thin films (especially for use as a protective film, reflective layer, and semi-transmissive film layer) having excellent properties such as excellent adhesion to the recording layer, mechanical properties, and high transmittance. A certain patching target can be provided. As described above, there are excellent effects that it is possible to significantly improve the throughput by improving the characteristics of the optical information recording medium, reducing the equipment cost, and improving the film forming speed.

Al ₂ O _{3, MgO,} is a diagram illustrating a SiO 2, ZnO vapor pressure curve. It is a figure which shows the result of the thermodynamic simulation of the behavior of ZnO in preparation by hot press (HP). 0.5 wt% of _B 2 _{O 3} as a low-melting-point oxide, when adding 1.0 wt%, compared to no addition is a diagram showing the low temperature shrinkage temperature.

The sputtering target of the present invention has a low melting point oxidation with respect to a basic composition comprising three or four elements of zinc (Zn), aluminum (Al), magnesium (Mg) and / or silicon (Si), and oxygen (O). A target containing a metal that forms an object, wherein the Al content is Al₂O₃0.2-3.0 mol% in terms of conversion, Mg and / or Si content is MgO and / or SiO₂1 to 27 mol% in terms of conversion and the balance is a ZnO content of Zn, and the metal that forms a low melting point oxide having a melting point of 1000 ° C. or less is 0.1% in terms of oxide weight. It is a sputtering target characterized by containing ˜20 wt%, and has a high density and a low refractive index.
That is, Al imparting conductivity in ZnO₂O₃MgO, SiO for adjusting the refractive index ₂And a low melting point oxide having a melting point of 1000 ° C. or lower is dispersed.
In the present invention, the metal content in the sintered body is defined in terms of each oxide, but a part or all of each metal in the sintered body exists as a composite oxide. Moreover, in the component analysis of the sintered body normally used, each content is measured not as an oxide but as a metal.

The ZnO—Al ₂ O ₃ —MgO—SiO ₂ target (ZnO main component) described in Patent Document 4 needs to be densified in order to perform stable sputtering. As a method of increasing the density, it is conceivable to increase the sintering temperature. However, in this system, the vapor pressure of ZnO is high (see FIG. 1), so it is difficult to increase the density due to decomposition (evaporation) of ZnO. is there.

Further, in the production by hot pressing, there is a problem that ZnO is reduced by contact with carbon at a high temperature and the die is eroded.
As a result of thermodynamic simulation of ZnO behavior (see FIG. 2) for the production by hot pressing (HP), ZnO reduction occurs at 1100 ° C. even under pressure under conditions where carbon coexists. Therefore, it is necessary to lower the sintering temperature below 1100 ° C.

As methods for low-temperature sintering and densification, the addition of a low-melting point oxide was examined, and the sintering temperature was examined to be less than 1100 ° C. As a result, it was found that the addition of an oxide having a melting point of 1000 ° C. or lower is effective.
As this low melting point oxide, especially from B ₂ O ₃ , P ₂ O ₅ , K ₂ O, V ₂ O ₅ , Sb ₂ O ₃ , TeO ₂ , Ti ₂ O ₃ , PbO, Bi ₂ O ₃ , MoO ₃ Addition of selected materials is effective.

Table 1 shows the melting points of these low melting point oxides. Among these, B ₂ O ₃ is particularly effective in handling since it is not toxic. As a result, the density of the target can be increased, there is no abnormal discharge, and stable sputtering is possible.
The metal forming the low melting point oxide can effectively lower the sintering temperature by adding 0.1 wt% or more and 20.0 wt% or less in terms of oxide weight. Further, it is preferably 0.1 wt% or more and 10.0 wt% or less, and the sintering temperature can be lowered without significantly impairing the properties of the base material, and more preferably 0.1 wt% or more and 5.0 wt%. In this range, the sintering temperature can be lowered without changing the characteristics of the base material.

The actions and effects of the other component compositions (materials) are the same as in Patent Document 4, but will be described again. That is, when Al ₂ O ₃ is less than 0.2 mol%, the bulk resistance value increases and the object of the present invention cannot be achieved. Further, if Al ₂ O ₃ exceeds 3.0 mol%, the bulk resistance increases, and DC sputtering cannot be performed.

MgO and SiO ₂ can be added individually and in combination, respectively, and the object of the present invention can be achieved. If MgO and / or SiO ₂ is less than 1 mol%, a low refractive index cannot be achieved, and if it exceeds 27 mol%, the bulk resistance value is increased and the film formation rate is remarkably lowered. Therefore, the composition range of the above components is preferable.
Note that the MgO and / or SiO ₂ is to 10～27Mol% is further preferred. This is because the transmittance is further improved and the refractive index can be reduced by adding about 10 to 27 mol% compared to the case where MgO and / or SiO2 is ₁ to 10 mol%.

The sputtering target of the present invention is useful for industrially producing a low refractive index optical thin film for optical discs having a refractive index of 2.00 or less (550 nm). In particular, it can be used as a target for forming a protective layer, a reflective layer, or a semi-transmissive layer of an optical information recording medium.
As the capacity of optical information recording media has increased, write-once and rewritable DVDs that support multi-layer recording have appeared. In the case of adopting such a multilayer structure, the reflective layer of the first layer located between the first layer and the second layer needs to have transparency in order to irradiate recording / reading light to the second layer. When an Ag alloy is used as the semi-transmissive layer, sulfurization due to reaction with ZnS—SiO ₂ used as a protective layer becomes a problem.

As such a semi-transmissive layer free from the problem of sulfidation, a semi-transmissive layer having arbitrary optical characteristics can be formed by alternately stacking a high refractive index layer and a low refractive index layer. The target of the present invention can be suitably used as a low refractive index layer constituting a semi-transmissive layer in addition to the protective layer. And the bulk resistance of a target can achieve 10 ohm * cm or less. Reduction of the bulk resistance value enables high-speed film formation by DC sputtering. Depending on the selection of the material, RF sputtering is required, but even in that case, the film forming speed is improved. As described above, the optimum range of the sputter deposition rate and optical characteristics (refractive index, transmittance) is obtained. A range that deviates from the numerical range tends to be inferior to the above characteristics.

When an attempt is made to form a low refractive index film for optical adjustment, since many of the low refractive index materials are not conductive, there is a problem that DC sputtering cannot be performed and the film formation rate is slow. On the other hand, in general conductive transparent film materials such as ITO and AZO, DC sputtering is possible, but the refractive index becomes as high as 2.0 or more. Therefore, it can be said that the present invention has a refractive index of 2.0 or less and can perform DC sputtering.

Since the volume resistivity of the sputtering target needs to be able to be DC sputtered, the upper limit is 10 Ωcm at which DC sputtering is possible. Note that the volume resistivity of the thin film formed by sputtering using this target is in the range of 1 × 10 ³ Ω · cm to 1 × 10 ⁹ Ω · cm.

The extinction coefficient (λ = 450 nm) of the film obtained by sputtering the sputtering target of the present invention is preferably less than 0.01, although it depends on the film configuration and film thickness when used. Zero is ideal when a transparent film is required. The present invention is particularly aimed at the short wavelength side in the visible light region. In general, an oxide film is difficult to suppress absorption on the short wavelength side in the visible light region, has absorption on the short wavelength side, and tends to be a yellowish film (for example, IZO is a yellowish film). .

In the production of the sputtering target of the present invention, the raw material Al ₂ O ₃ powder is 0.2 to 3.0 mol%, MgO and / or SiO ₂ powder is 1 to 27 mol%, the remainder is ZnO powder, and these are 100 mol. The basic raw material powder is adjusted so that it becomes%, and further, 0.1 to 20 wt% of a low melting point oxide powder having a melting point of 1000 ° C. or lower is added to obtain a raw material for sintering. Next, this mixed powder is hot-pressed at a temperature exceeding 800 ° C. and lower than 1100 ° C. Thus, _Al 2 _{O 3} is 0.2 to 3.0 mol%, MgO and / or SiO ₂ is 1 to 27 mol%, relative to the basic composition and the balance ZnO (composition of 100 mol%), more melting point A sputtering target containing 0.1 to 20 wt% of a metal forming a low melting point oxide of 1000 ° C. or less in terms of oxide weight can be obtained.
And by this sintering, a relative density can be 98% or more, and the bulk resistance of a target can be 10 ohm * cm or less.

Furthermore, Al ₂ O ₃ powder and ZnO powder as raw materials are mixed in advance and calcined in advance, and then pre-sintered Al ₂ O ₃ —ZnO powder (AZO powder) is mixed with MgO and / or SiO ₂ powder. Furthermore, it is possible to mix and sinter the powder of low melting point oxide.
This is because when MgO and / or SiO ₂ powder is simply added, Al ₂ O ₃ and MgO and / or SiO ₂ are likely to react to form spinel, and the bulk resistance value tends to increase. Therefore, in order to achieve a lower bulk resistance of the sintered body, it is desired to sinter using a presintered Al ₂ O ₃ —ZnO content (AZO powder).

Further, the raw material Al ₂ O ₃ powder and ZnO powder are mixed in advance and preliminarily calcined to obtain AZO powder, and the raw material MgO powder and SiO ₂ powder are similarly mixed and calcined. It is recommended that the MgO—SiO ₂ calcined powder and the low melting point oxide powder be mixed and sintered with the calcined Al ₂ O ₃ —ZnO powder (AZO powder). This is because spinelization can be further suppressed and low bulk resistance can be achieved.

In addition, since the sputtering target of the present invention can have a relative density of 98% or more as described above, it has an excellent effect of improving the uniformity of the sputtered film and suppressing the generation of particles during sputtering.
By using the sputtering target described above, it is possible to provide an optical information recording medium which forms at least a part of the optical information recording medium structure as a thin film. Furthermore, by using the sputtering target, it is possible to produce an optical information recording medium in which a part of the structure of the optical information recording medium is formed as at least a thin film and is disposed adjacent to the recording layer or the reflective layer. .

In the present invention, by using a target containing zinc oxide as a main component in this way, conductivity can be retained, whereby a thin film can be formed by direct current sputtering (DC sputtering). DC sputtering is superior to RF sputtering in that the deposition rate is high and sputtering efficiency is good, and the throughput can be significantly improved.
Further, the DC sputtering apparatus is advantageous in that it is inexpensive, easy to control, and consumes less power. Since it is possible to reduce the thickness of the protective film itself, it is possible to further improve productivity and prevent substrate heating. In the present invention, it may be necessary to perform RF sputtering depending on the manufacturing conditions and selection of materials, but even in such a case, the film formation rate is improved.

Furthermore, the thin film formed using the sputtering target of the present invention forms a part of the structure of the optical information recording medium and is arranged adjacent to the recording layer or the reflective layer. Since it is not used, there is no contamination due to S, and there is no significant diffusion of sulfur component into the recording layer material arranged so as to be sandwiched between protective layers, thereby eliminating the deterioration of the recording layer.
In addition, pure Ag or Ag alloy having high reflectivity and high thermal conductivity has been used for the reflective layer material in order to increase the capacity and increase the recording speed, but the sulfur component to the adjacent reflective layer has been used. Diffusion is also eliminated, and the reflective layer material is similarly corroded and has an excellent effect of eliminating the cause of deterioration of characteristics such as reflectance of the optical information recording medium.

Furthermore, by using the sputtering target of the present invention, productivity is improved, a material with excellent quality can be obtained, and an optical recording medium having an optical disk protective film can be manufactured stably at low cost. There is.
The improvement in the density of the sputtering target of the present invention can reduce the number of vacancies, refine the crystal grains, and make the sputtering surface of the target uniform and smooth, thereby reducing particles and nodules during sputtering, and further improving the target life. It has a remarkable effect that it can be lengthened, and there is little variation in quality, so that mass productivity can be improved.

  Hereinafter, description will be made based on Examples and Comparative Examples. In addition, a present Example is an example to the last, and is not restrict | limited at all by this example. In other words, the present invention is limited only by the scope of the claims, and includes various modifications other than the examples included in the present invention.

Example 1
4N equivalent ZnO powder, 4N equivalent MgO powder with an average particle size of 5 μm or less, 4N equivalent Al ₂ O ₃ powder with an average particle size of 5 μm or less, 4N equivalent, SiO ₂ powder with an average particle size of 5 μm or less, 4N A B ₂ O ₃ powder having an average particle size of 5 μm or less was prepared.
Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the ratio of the raw materials, ZnO powder: 72.0mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.2 mol%, SiO ₂ powder: a 2.2 mol%, the total The basic raw material was 100 mol%. And this further _B 2 _{O 3} powder: blended 1.0 wt% was sintered raw material. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 99.6%, and the bulk resistance was 3.5 × 10 ⁻³ Ω · cm (3.5 mΩ · cm).
In addition, the density displayed in this specification means a relative density. Each relative density is obtained by measuring the density of a target, which is a produced complex oxide, with respect to the theoretical density of the target calculated from the density of the raw material, and obtaining the relative density from each density. Since it is not a simple mixture of raw materials, as shown in Table 2, there is an example in which the relative density exceeds 100%.

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 2.8 Å / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.943, volume resistivity: 2 × 10 ⁵ Ω · cm, and extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Comparative Example 1)
ZnO powder of 4N equivalent and 5 μm or less, 4O equivalent MgO powder of 5 μm or less in average particle diameter, 4N equivalent of Al ₂ O ₃ powder of 5 μm or less in average particle diameter, 4N equivalent of SiO ₂ powder of 5 μm or less in average particle diameter prepared did. Next, these powders were prepared in the mixing ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1150 ° C. The pressure of the hot press was 220 kg / cm ² .
As shown in Table 2, the ratio of the raw materials, ZnO powder: 72.0mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.2 mol%, SiO ₂ powder: was 2.2 mol%. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target was 97.6%, which was lower than that in Example 1. The bulk resistance was 2.0 × 10 ⁻³ Ω · cm.

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. Although the film formation rate was 2.2 liters / sec, abnormal discharge and generation of particles occurred during sputtering, and stable DC sputtering could not be performed. The refractive index (wavelength 550 nm) of the film formation sample was 1.948, volume resistivity: 1 × 10 ⁵ Ω · cm, extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Comparative Example 2)
ZnO powder of 4N equivalent and 5 μm or less, 4O equivalent MgO powder of 5 μm or less in average particle diameter, 4N equivalent of Al ₂ O ₃ powder of 5 μm or less in average particle diameter, 4N equivalent of SiO ₂ powder of 5 μm or less in average particle diameter prepared did. Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. (lower temperature than Comparative Example 1). The pressure of the hot press was 220 kg / cm ² .
As shown in Table 2, the ratio of the raw materials, ZnO powder: 72.0mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.2 mol%, SiO ₂ powder: a 2.2 mol%, compared Same as Example 1. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target was 90.9%, which was lower than that of Example 1 and further lower than that of Comparative Example 1. The bulk resistance was 3.0 × 10 ⁻³ Ω · cm.

Using the above-finished 6-inch φ target, DC sputtering was attempted under the same conditions as in Comparative Example 1, but was interrupted because stable DC sputtering could not be performed. These conditions and results are summarized in Table 2.

(Example 2)
4N equivalent ZnO powder, 4N equivalent MgO powder with an average particle size of 5 μm or less, 4N equivalent Al ₂ O ₃ powder with an average particle size of 5 μm or less, 4N equivalent, SiO ₂ powder with an average particle size of 5 μm or less, 4N A B ₂ O ₃ powder having an average particle size of 5 μm or less was prepared.
Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the raw material mixing ratio of, ZnO powder: 72.0mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.2 mol%, SiO ₂ powder: a 2.2 mol%, A total of 100 mol% was used as a basic raw material. And this further _B 2 _{O 3} powder: the sintering raw material by blending 0.5 wt%.
The blending ratio of B ₂ O ₃ powder was lower than that in Example 1. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 99.5%, and the bulk resistance was 2.9 × 10 ⁻³ Ω · cm (3.5 mΩ · cm). The density was slightly lower than in Example 1.

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 2.6 Å / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.945, volume resistivity: 2 × 10 ⁵ Ω · cm, and extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Example 3)
4N equivalent ZnO powder, 4N equivalent MgO powder with an average particle size of 5 μm or less, 4N equivalent Al ₂ O ₃ powder with an average particle size of 5 μm or less, 4N equivalent, SiO ₂ powder with an average particle size of 5 μm or less, 4N A B ₂ O ₃ powder having an average particle size of 5 μm or less was prepared.
Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the raw material mixing ratio of, ZnO powder: 89.3mol%, MgO powder: 9.2 mol%, _Al 2 _{O 3} powder: 0.7 mol%, SiO ₂ powder: a 0.8 mol%, A total of 100 mol% was used as a basic raw material. And this further _B 2 _{O 3} powder: blended 1.0 wt% was sintered raw material. The blending ratio of B ₂ O ₃ powder was the same as in Example 1.
The mixing ratio of other raw materials was changed. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 101.6%, and the bulk resistance was 2.2 × 10 ⁻³ Ω · cm (2.2 mΩ · cm). The density was further improved as compared with Example 1.

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 3.0 liters / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.973, volume resistivity: 3 × 10 ³ Ω · cm, and extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

Example 4
4N equivalent ZnO powder, 4N equivalent MgO powder with an average particle size of 5 μm or less, 4N equivalent Al ₂ O ₃ powder with an average particle size of 5 μm or less, 4N equivalent, SiO ₂ powder with an average particle size of 5 μm or less, 4N A B ₂ O ₃ powder having an average particle size of 5 μm or less was prepared.
Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the raw material mixing ratio of, ZnO powder: 68.9mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.1 mol%, SiO ₂ powder: 5.4 mol%, the total The basic raw material was 100 mol%. And this further _B 2 _{O 3} powder: blended 1.0 wt% was sintered raw material. The blending ratio of B ₂ O ₃ powder was the same as in Example 2.
The mixing ratio of other raw materials was changed. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 101.6%, and the bulk resistance became 3.3 × 10 ⁻³ Ω · cm (3.3 mΩ · cm). The density was further improved as compared with Examples 1 and 2.

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 2.9 Å / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.899, volume resistivity: 1 × 10 ⁶ Ω · cm, extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Example 5)
4N equivalent ZnO powder, 4N equivalent MgO powder with an average particle size of 5 μm or less, 4N equivalent Al ₂ O ₃ powder with an average particle size of 5 μm or less, 4N equivalent, SiO ₂ powder with an average particle size of 5 μm or less, 4N Correspondingly, Bi ₂ O ₃ powder having an average particle size of 5 μm or less was prepared.
Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the raw material mixing ratio of, ZnO powder: 72.0mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.2 mol%, SiO ₂ powder: a 2.2 mol%, A total of 100 mol% was used as a basic raw material. And this further _Bi 2 _{O 3} powder: blended 1.0 mol% was sintered raw material. The blending ratio of Bi ₂ O ₃ powder was the same as in Example 1. The difference from Example 1 is that Bi ₂ O ₃ powder was used instead of B ₂ O ₃ powder.
After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target was 98.5%, and the bulk resistance was 2.3 × 10 ⁻³ Ω · cm (2.3 mΩ · cm).

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 2.8 Å / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.953, volume resistivity: 5 × 10 ⁵ Ω · cm, and extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Example 6)
4N equivalent ZnO powder of 5 μm or less, 4N equivalent of Al ₂ O ₃ powder with an average particle diameter of 5 μm or less, 4N equivalent of SiO ₂ powder with an average particle diameter of 5 μm or less, 4N equivalent of B ₂ O ₃ with an average particle diameter of 5 μm or less Prepared flour. Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the ratio of the raw materials, ZnO powder: 80.5mol%, _Al 2 _{O 3} powder: 2.5 mol%, SiO ₂ powder: a 17.0Mol%, as 100 mol% in total, and the basic raw material did. Further, B ₂ O ₃ powder: 1.5 wt% was further added as an additive to obtain a sintered raw material. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 99.6%, and the bulk resistance became 1.3 × 10 ⁻³ Ω · cm (1.3 mΩ · cm).

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 2.4 Å / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.84, volume resistivity: 6 × 10 ⁴ Ω · cm, extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Example 7)
ZnO powder with 4N equivalent and 5 μm or less, MgO powder with 4N equivalent and average particle size of 5 μm or less, Al ₂ O ₃ powder with 4N equivalent and average particle size of 5 μm or less, B ₂ O ₃ powder with 4N equivalent and average particle size of 5 μm or less Prepared. Next, these powders were blended to the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1050 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the ratio of the raw materials, ZnO powder: 79.9mol%, MgO powder: 17.6 mol%, _Al 2 _{O 3} powder: the 2.5 mol%, as 100 mol% in total, and the basic raw material . And this further _B 2 _{O 3} powder: blended 1.5 wt% was sintered raw material. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 99.4%, and the bulk resistance was 2.1 × 10 ⁻³ Ω · cm (2.1 mΩ · cm).

Sputtering was performed using the above-mentioned 6-inch φ-sized target that was finished. The sputtering conditions were DC sputtering, sputtering power of 500 W, Ar-2% O ₂ mixed gas pressure of 0.5 Pa, and a film thickness of 1500 mm was formed. The film formation rate was 2.6 Å / sec, stable DC sputtering was possible, and good sputtering properties were obtained. The refractive index (wavelength 550 nm) of the film formation sample was 1.95, volume resistivity: 7 × 10 ⁴ Ω · cm, and extinction coefficient (λ = 450 nm): <0.01. These conditions and results are summarized in Table 2.

(Comparative Example 3)
4N equivalent ZnO powder, 4N equivalent MgO powder with an average particle size of 5 μm or less, 4N equivalent Al ₂ O ₃ powder with an average particle size of 5 μm or less, 4N equivalent, SiO ₂ powder with an average particle size of 5 μm or less, 4N A B ₂ O ₃ powder having an average particle size of 5 μm or less was prepared.
Next, these powders were blended at the blending ratio shown in Table 2, mixed, and then hot pressed (HP) at a temperature of 1000 ° C. The pressure of the hot press was 220 kg / cm ² .

As shown in Table 2, the ratio of the raw materials, ZnO powder: 72.0mol%, MgO powder: 24.6mol%, _Al 2 _{O 3} powder: 1.2 mol%, SiO ₂ powder: a 2.2 mol%, the total The basic raw material was 100 mol%. And this further _B 2 _{O 3} powder: the sintering raw material by blending 0.5 wt%. After sintering, the sintered body was finished into a target shape by machining. The density of the sintered compact target reached 99.6%, and the bulk resistance was 3.2 × 10 ⁻³ Ω · cm (3.2 mΩ · cm).

Using the above-finished 6-inch φ target, DC sputtering was attempted under the same conditions as in Comparative Example 1, but was interrupted because stable DC sputtering could not be performed. These conditions and results are summarized in Table 2.

(Overview of comprehensive evaluation by examples and comparative examples)
As apparent from Comparative Example 1 above, without addition of the low melting point oxide, the density was 97.6% and low in the hot press at 1150 ° C. and 220 kg / cm ² . It can be seen that reduction of ZnO occurs even at this temperature, and low-temperature sintering is necessary.
As shown in Comparative Example 2, when HP was carried out at 1050 ° C. and 220 kg / cm ² for the same raw material, the density further decreased to 90.9%.

As shown in the above examples, when B ₂ O ₃ was added as a low melting point oxide, it was confirmed that the shrinkage temperature was lowered when 0.5 wt% and 1.0 wt% were added (see FIG. 3).
As shown in Example 1 and Example 2, for B ₂ O ₃ addition of 0.5 and 1.0 wt%, the densities were 99.6 and 99.5%, respectively. Achieved. The bulk resistance value was 2.0 to 4.0 mΩcm and 10 mΩcm or less, and DC sputtering was possible.

As a further reduction in temperature, H / P was performed at 1000 ° C. for 0.5 wt% of B ₂ O ₃ added as shown in Comparative Example 3. As a result, the density was 93.4%, and high density was achieved. There wasn't. Further, even when the composition of ZnO—Al ₂ O ₃ —MgO—SiO ₂ is changed, as shown in Examples 3 and 4, low temperature sintering and high density can be achieved by adding B ₂ O _3. It was confirmed that there was. In either case, a bulk resistance value with no problem in DC sputtering was obtained.

  For the above, B as the low melting point oxide₂O₃Is an evaluation result for the case of adding and not adding Bi.₂O₃As shown in Example 5, when B is used, B₂O₃The same effect as the addition was obtained.
Further, although not shown in the examples, Sb₂O₃, P₂O₅, K₂O, V₂O₅, TeO ₂, Ti₂O₃, PbO, MoO₃Even when this material is used, it is presumed that the same effect is obtained because it is a low melting point oxide.
Further, the above description has been made on the case where the low melting point oxide is added alone, but the same effect can be obtained when these are added in combination.

Furthermore, the major features of the present invention are that the target bulk resistance value is reduced, conductivity is imparted, and stable DC sputtering is enabled by increasing the relative density to 98% or higher. And there is a remarkable effect that the controllability of sputtering, which is the feature of this DC sputtering, can be facilitated, the film forming speed can be increased, and the sputtering efficiency can be improved. RF sputtering is performed as necessary, but even in this case, the film formation rate is improved.
In addition, particles (dust generation) and nodules generated during sputtering during film formation can be reduced, quality variation can be reduced and mass productivity can be improved, and optical recording media with optical disk protective films can be stably manufactured at low cost. There is a remarkable effect that it can be manufactured. Therefore, the present invention is extremely useful for optical thin films.

The thin film formed using the sputtering target of the present invention forms part of the structure of the optical information recording medium and does not use ZnS, so that there is no diffusion of the sulfur component into the recording layer material. There is a remarkable effect that the recording layer is not deteriorated.
In addition, when pure Ag or Ag alloy having high heat conductivity and adjacent reflectivity is used for the reflection layer, diffusion of sulfur component to the reflection layer is eliminated, and the reflection layer is deteriorated due to corrosion deterioration. It has an excellent effect of causing the cause to be wiped out.
Further, as a semi-transmissive layer free from the problem of sulfuration, a semi-transmissive layer having arbitrary optical characteristics can be formed by alternately laminating a high refractive index layer and a low refractive index layer. The target of the present invention is also useful as a low refractive index layer constituting a semi-transmissive layer. Furthermore, it can also be applied to organic EL TV applications, touch panel electrodes, hard disk seed layers, and the like.

Claims (17)

Contains a metal that forms a low-melting-point oxide with respect to a basic composition consisting of three elements or four elements of zinc (Zn), aluminum (Al), magnesium (Mg) and / or silicon (Si), and oxygen (O) to a target, 0.2 to 3.0 mol% Al content in terms _{of Al} 2 _{O 3,} Mg and / or Si 1 to 27 mol% content of MgO and / or SiO ₂ in terms of, With respect to the basic composition consisting of the ZnO content of Zn, the remainder further contains 0.1 to 20 wt% of a metal that forms a low melting point oxide having a melting point of 1000 ° C or less in terms of oxide weight. Sputtering target. The sputtering target according to claim 1, wherein the content of the metal forming the low melting point oxide is 0.1 to 10 wt% in terms of oxide. As the low melting point _oxide, selected from _{B 2 O 3, P 2 O} 5, K 2 O, V 2 O 5, Sb 2 O 3, TeO 2, Ti 2 O 3, PbO, Bi 2 O 3, MoO 3 The sputtering target according to claim 1, wherein the sputtering target is one or more materials. The sputtering target according to any one of claims 1 to 3, wherein the content of Mg and / or Si is 10～27Mol% of MgO and / or SiO ₂ conversion. A relative density is 98% or more, The sputtering target as described in any one of Claims 1-4 characterized by the above-mentioned. The sputtering target according to claim 1, wherein the target has a bulk resistance of 10 Ω · cm or less. 7. The optical information recording medium, which is used for an optical thin film for forming a protective layer, a reflective layer or a semi-transmissive layer, for an organic EL television, for a touch panel electrode, and for a hard disk seed layer. The sputtering target according to claim 1. Raw materials for basic sintering so that the total amount of Al ₂ O ₃ powder is 0.2 to 3.0 mol%, MgO and / or SiO ₂ powder is 1 to 27 mol%, and the balance is ZnO powder, and the total amount thereof is 100 mol%. A powder is prepared, and 0.1 to 20 wt% of a low melting point oxide powder having a melting point of 1000 ° C. or lower is further added thereto to obtain a sintered raw material. The sintered raw material exceeds 800 ° C. and less than 1150 ° C. A method for producing a sputtering target, comprising hot pressing. The method for producing a sputtering target according to claim 8, wherein the relative density is 98% or more. The method for producing a sputtering target according to claim 8, wherein the bulk resistance is 10 Ω · cm or less. Contains a metal that forms a low-melting-point oxide with respect to a basic composition consisting of three elements or four elements of zinc (Zn), aluminum (Al), magnesium (Mg) and / or silicon (Si), and oxygen (O) to a thin, 0.2 to 3.0 mol% Al content in terms _{of Al} 2 _{O 3,} Mg and / or Si 1 to 27 mol% content of MgO and / or SiO ₂ in terms of, With respect to the basic composition consisting of the ZnO content of Zn, the remainder further contains 0.1 to 20 wt% of a metal that forms a low melting point oxide having a melting point of 1000 ° C or less in terms of oxide weight. And thin film. The thin film according to claim 11, wherein the content of the metal forming the low melting point oxide is 0.1 to 10 wt% in terms of oxide. Low melting point oxide is B₂O₃, P₂O₅, K₂O, V₂O₅, Sb₂O₃, TeO₂, Ti ₂O₃, PbO, Bi₂O₃, MoO₃The thin film according to claim 11, wherein the thin film is one or more selected from the group consisting of: 14. The thin film according to claim 11, wherein the content of Mg and / or Si is 10 to 27 mol% in terms of MgO and / or SiO ₂ .   The refractive index (wavelength 550 nm) is 2 or less, The thin film as described in any one of Claims 11-14 characterized by the above-mentioned.   The thin film according to claim 11, wherein the extinction coefficient (λ = 450 nm) is less than 0.01. 17. The optical information recording medium is used for an optical thin film for forming a protective layer, a reflective layer or a semi-transmissive layer, for an organic EL television, for a touch panel electrode, and for a seed layer of a hard disk. A thin film according to claim 1.