JP2010090412A - Pd-cr-w-based sputtering target and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive sputtering target alternative for a ruthenium target, and a method for manufacturing the same. <P>SOLUTION: The Pd-Cr-W-based sputtering target contains Pd, Cr and W as main components. In the structure of the target, at least one of the Cr phase and the W phase is dispersed in an alloy matrix containing at least one of Cr and W, and the balance Pd with inevitable impurities. The content of Cr to the entire target is 5-50 at%, and the content of W is 5-40 at%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a Pd—Cr—W-based sputtering target and a method for manufacturing the same, and more particularly to a Pd—Cr—W-based sputtering target that can be used as a substitute for a ruthenium target and a method for manufacturing the same.

  Ruthenium is used not only as a thin film electrode for semiconductor devices such as DRAM and FeRAM, but also as an intermediate layer of a recording medium such as a hard disk (for example, Patent Document 1).

  On the other hand, in a hard disk, a perpendicular magnetic recording method capable of stably performing high-density recording is becoming mainstream.

FIG. 1 schematically shows a cross section in the thickness direction of an example of a perpendicular magnetic recording type hard disk. As shown in FIG. 1, in the hard disk 100, a soft magnetic backing layer 104 is laminated on a substrate 102 such as glass, and an intermediate layer 106 is laminated on the soft magnetic backing layer 104. A CoCrPt—SiO ₂ recording layer (magnetic layer) 108 is laminated thereon. Each layer is formed by performing sputtering using a target corresponding to the composition.

The intermediate layer 106 is a ruthenium layer that functions to satisfactorily epitaxially grow the CoCrPt—SiO ₂ recording layer (magnetic layer) 108 and is formed by sputtering using a ruthenium target. By making the intermediate layer 106 a ruthenium layer, Co (001) is epitaxially grown on the Ru (001) orientation, and the recording layer (magnetic layer) 108 realizes a good C-axis orientation. Good perpendicular magnetic recording characteristics can be realized.

  Here, ruthenium is also used in an in-plane magnetic recording medium. In order to suppress thermal instability of recording, a ruthenium layer of several atomic layers is sandwiched between recording layers (magnetic layers). However, the thickness of the ruthenium layer used as the intermediate layer 106 in the perpendicular magnetic recording medium is 10 to 20 times the thickness of the ruthenium layer used in the in-plane magnetic recording medium.

  For this reason, as the data recording system of the hard disk is changed from the in-plane magnetic recording system to the perpendicular magnetic recording system, the demand for ruthenium is rapidly increasing, and the price of ruthenium is rising.

  In order to cope with the rise in the ruthenium price, the appearance of an inexpensive sputtering target that can replace the ruthenium target is awaited.

JP-A-2005-113174

  This invention is made | formed in view of this condition, Comprising: It aims at providing a cheap sputtering target which can substitute a ruthenium target, and its manufacturing method.

  A first aspect of the Pd—Cr—W based sputtering target according to the present invention that has solved the above problems is a Pd—Cr—W based sputtering target containing Pd, Cr, and W as main components, wherein Cr and W In the alloy matrix containing at least one of the above, the balance being Pd and inevitable impurities, and having a structure in which at least one of the Cr phase and the W phase is dispersed, Cr with respect to the entire target The content of is 5 to 50 at%, and the content of W is 5 to 40 at%.

  The contents of Cr and W in the alloy matrix can be set to, for example, 0 to 35 at% and 0 to 22 at%, respectively.

  Moreover, it is preferable that the average size of the phase which combined both Cr phase and W phase in the said Pd-Cr-W type | system | group sputtering target is 3-100 micrometers. Here, the average size of the combined phase of both the Cr phase and the W phase is a phase in which a straight parallel line is drawn on a metal microscope photograph at a magnification of 140 times, and the straight line is a combination of both the Cr phase and the W phase. Is obtained by measuring the lengths of all the overlapping portions and calculating the average value of the lengths. The number of parallel straight lines drawn on the metallurgical micrograph is the number at which the number of overlapping portions with the combined phase of both the Cr phase and the W phase is 200 or more.

  Moreover, it is preferable that the oxygen concentration in the said Pd-Cr-W type | system | group sputtering target is 1500 mass ppm or less.

  The Pd—Cr—W based sputtering target can be suitably used for a magnetic recording medium.

  The method for producing a Pd—Cr—W-based sputtering target according to the present invention that solves the above-described problems is an atomizing method in which an alloy powder containing at least one of Cr and W and the balance of Pd and inevitable impurities is used. The prepared alloy powder is prepared by adding at least one of the Cr powder and the W powder so that the Cr content is 5 to 50 at% and the W content is 5 to 40 at%. A mixed powder is produced by mixing, and then the produced mixed powder is heated and molded under pressure.

  The contents of Cr and W in the alloy matrix can be set to, for example, 0 to 35 at% and 0 to 22 at%, respectively.

  The average size of the combined phase of both the Cr phase and the W phase in the obtained Pd—Cr—W-based sputtering target is preferably 3 to 100 μm.

  Moreover, it is preferable that the oxygen concentration in the Pd—Cr—W-based sputtering target to be obtained is 1500 ppm by mass or less.

  The atomizing method is preferably performed using argon gas or nitrogen gas.

  The atomization method is preferably performed at an injection temperature of 1600 to 2100 ° C.

  Moreover, it is preferable to shape | mold the produced said mixed powder by the discharge plasma sintering method.

  The obtained Pd—Cr—W-based sputtering target can be suitably used for a magnetic recording medium.

  The 2nd aspect of the Pd-Cr-W type sputtering target concerning the present invention which solved the above-mentioned subject is manufactured by the above-mentioned manufacturing method.

  The Pd—Cr—W-based sputtering target according to the present invention can replace the ruthenium target and is inexpensive.

  When the average size of the combined phase of both the Cr phase and the W phase in the Pd—Cr—W-based sputtering target is 3 to 100 μm, sputtering using the target becomes better.

  Further, when the oxygen concentration in the Pd—Cr—W-based sputtering target is suppressed to 1500 mass ppm or less, sputtering using the target becomes better.

  Since the layer formed using the Pd—Cr—W-based sputtering target according to the present invention approximates the crystal structure of ruthenium, the Pd—Cr—W-based sputtering target according to the present invention is a magnetic recording medium. Suitable for producing an intermediate layer.

  According to the method for producing a Pd—Cr—W sputtering target according to the present invention, a ruthenium target can be substituted and an inexpensive sputtering target can be produced.

  When the average size of the combined phase of both the Cr phase and the W phase in the obtained Pd—Cr—W-based sputtering target is 3 to 100 μm, sputtering using the target is better. It will be something.

  Moreover, when it manufactures so that the oxygen concentration in the obtained Pd-Cr-W type | system | group sputtering target may be suppressed to 1500 mass ppm or less, sputtering using this target will become a better thing.

  When the atomization method is performed using argon gas or nitrogen gas, the oxygen concentration in the obtained Pd—Cr—W-based sputtering target can be further reduced.

  When the atomizing method is performed at an injection temperature of 1600 to 2100 ° C., even when a crucible made of magnesia is used, the amount of oxygen that enters the molten metal from the crucible is small, and the viscosity of the molten metal becomes a viscosity suitable for atomization.

  When the produced mixed powder is molded by the discharge plasma sintering method, the amount of impurities in the obtained target can be reduced.

  Moreover, since the layer formed using the obtained Pd—Cr—W-based sputtering target approximates the crystal structure of ruthenium, the obtained Pd—Cr—W-based sputtering target is an intermediate layer of a magnetic recording medium. Suitable for making.

  Hereinafter, embodiments of the present invention will be described in detail.

1. Components and Structure of Sputtering Target A Pd—Cr—W-based sputtering target according to an embodiment of the present invention is a Pd—Cr—W-based sputtering target containing Pd, Cr, and W as main components, and includes Cr and W. In the alloy matrix containing at least one of the above, the balance being Pd and inevitable impurities, and having a structure in which at least one of the Cr phase and the W phase is dispersed, Cr with respect to the entire target The content of is 5 to 50 at%, and the content of W is 5 to 40 at%.

1-1. About Pd Pd is a noble metal like Ru, and the atomic number of Pd is 46, which is close to the atomic number 44 of Ru, and characteristics such as atomic radius are similar to those of Ru. Furthermore, Pd is relatively inexpensive among noble metals. For this reason, Pd has a role of becoming a main component of a target that can substitute for a Ru target.

1-2. Regarding Cr and W Cr and W have a body-centered cubic structure (bcc), and a crystal structure of Pd in an intermediate layer obtained by sputtering by introducing stacking faults into the crystal structure of Pd having a face-centered cubic structure (fcc). In the hexagonal close-packed structure (hcp). Cr also has a role of improving the durability of the Pd—W layer obtained by sputtering.

  The Cr content with respect to the entire target is 5 to 50 at%, and the W content is 5 to 40 at%.

  When the Cr content is less than 5 at% or the W content is less than 5 at%, the amount of stacking faults introduced into the crystal structure of Pd in the intermediate layer formed by sputtering using the target is small. Too little, the crystal structure of Pd in the intermediate layer does not approach the hexagonal close-packed structure (hcp) of Ru, and a good c-axis oriented recording layer (magnetic layer) can be formed on the intermediate layer. Can not. In addition, when the content of Cr is less than 5 at%, the durability of the Pd—W layer obtained by sputtering is deteriorated.

  On the other hand, if the Cr content exceeds 50 at%, the orientation of the Pd—W layer obtained by sputtering is impaired, and the Ru layer cannot be substituted. On the other hand, if the W content exceeds 40 at%, the influence of W characteristics is too great in the intermediate layer formed by sputtering using the target, and the recording is well c-axis oriented on the intermediate layer. A layer (magnetic layer) cannot be formed.

1-3. About Alloy Matrix In the Pd—Cr—W based sputtering target according to the present embodiment, the alloy matrix contains at least one of Cr and W. For this reason, there is no place where only Pd exists in the entire target, and Pd always coexists with Cr or W, or coexists with Cr and W. As a result, in the sputtering using the target according to the present embodiment, the speed at which a specific portion is scraped is not extremely increased, and the sputtering becomes favorable.

  The content of Cr in the alloy matrix is preferably 0 to 35 at%, and the content of W is preferably 0 to 22 at%. If the Cr content in the alloy matrix exceeds 35 at%, the nozzle and Cr may react during atomization. Further, in order to make the W content exceed 22 at%, the temperature of the molten metal of the alloy needs to be heated to a temperature higher than 2100 ° C. However, in the case of a magnesia crucible, the temperature should be higher than 2100 ° C. Manufacturing cost increases.

1-4. About Dispersion Structure The Pd—Cr—W-based sputtering target according to the present embodiment has a structure in which at least one of a Cr phase and a W phase is dispersed in the alloy matrix. The average size of the combined phase of both the Cr phase and the W phase is preferably 3 to 100 μm. In order to reduce the average size of the combined phase of both the Cr phase and the W phase to less than 3 μm, it is necessary to sufficiently reduce the particle sizes of the Cr powder and the W powder used in the production. When the particle size of the powder is made small in this way, the oxygen content of the Cr powder and the W powder increases, and the oxygen content in the target increases too much. On the other hand, if the average size of the combined phase of both the Cr phase and the W phase is larger than 100 μm, it becomes easier to segregate Cr in the film when the film is formed by sputtering, or uniform erosion is caused during sputtering. It may be difficult to obtain.

  By having such a dispersion structure, in this embodiment, even if the Cr content in the alloy matrix is as low as 0 to 35 at% and the W content as low as 0 to 22 at%, for example, Cr relative to the entire target The content of can be increased to 5 to 50 at%, and the content of W can be increased to 5 to 40 at%.

  As will be described later in Examples, even when the target has a dispersed structure as in the present embodiment, the recording characteristics of the hard disk having the structure shown in FIG. The present inventor has confirmed that there is no difference in recording characteristics as compared with a hard disk using ruthenium Ru as an intermediate layer.

1-5. About oxygen concentration When the oxygen concentration in a target is high, an oxide will arise in a target and it will become an inclusion. The inclusions may become a base point of abnormal discharge during sputtering and become particles. In addition, oxygen in the target becomes an impurity in the film obtained by sputtering and deteriorates the characteristics of the film. For this reason, the oxygen concentration in the target is preferably as low as possible and is preferably 1500 ppm by mass or less.

1-6. About Inevitable Impurities In the Pd—Cr—W-based sputtering target according to the embodiment of the present invention, Pt, Au, Ag, Rh, Ir, Ru, Cu, Ni, Sb, Si, Mn, C, S, N, Fe, Mo etc. are mentioned.

2. About a manufacturing method The manufacturing method of the Pd-Cr-W type | system | group sputtering target which concerns on embodiment of this invention contains the at least 1 sort (s) of Cr and W, and atomizes the alloy powder which a remainder consists of Pd and an unavoidable impurity. At least one of the Cr powder and the W powder so that the content of Cr is 5 to 50 at% and the content of W is 5 to 40 at% with respect to the whole powder. The mixed powder is prepared by mixing and then, the prepared mixed powder is heated and molded under pressure.

  By adopting such a production method, the target obtained contains at least one of Cr and W, and the balance of the Cr phase and the W phase in the alloy matrix consisting of Pd and inevitable impurities. It will have a structure in which at least one phase is dispersed.

2-1. Preparation of atomized alloy powder Atomized into molten metal containing at least one of Cr and W (preferably containing 0 to 35 at% of Cr and 0 to 22 at% of W) with the balance being Pd and inevitable impurities. By applying the method, an atomized alloy powder having the same composition as the molten metal (hereinafter sometimes simply referred to as an alloy powder) is produced.

  If the temperature of the molten metal at the time of atomization is too high, oxygen is taken into the molten metal from the magnesia crucible and the oxygen concentration in the molten metal increases. On the other hand, if it is too low, the viscosity of the molten metal becomes high, and spraying for atomization becomes impossible. For this reason, the temperature of the molten metal at the time of atomizing is preferably a melting point of the molten alloy plus 200 to 350 ° C. In the present embodiment, it is preferably 1600 to 2100 ° C. More preferably, it is 1700-2000 degreeC.

  Since the produced atomized alloy powder contains at least one of Cr and W, there is no place where only Pd exists in the target obtained using the alloy powder, and Pd always coexists with Cr or W. Or it will coexist with Cr and W. As a result, in the sputtering using the obtained target, the speed at which a specific portion is cut is not extremely increased, and the sputtering using the target is satisfactory.

  The content of Cr in the produced atomized alloy powder is preferably 0 to 35 at%. In order for the Cr content in the atomized alloy powder to exceed 35 at%, the Cr content in the molten metal used in the atomization method needs to exceed 35 at%. If the content exceeds 35 at%, the nozzle and Cr may react during atomization.

  The content of W in the atomized alloy powder is preferably 0 to 22 at%. In order for the W content in the atomized alloy powder to exceed 22 at%, the W content in the molten metal used in the atomization method needs to exceed 22 at%, and the temperature of the molten metal is 2100 ° C. Although it is necessary to heat to a higher temperature, a magnesia crucible cannot be heated to a temperature higher than 2100 ° C., which increases the manufacturing cost.

  In addition, the atomizing method used for preparation of alloy powder is applicable regardless of the kind of atomizing method, for example, any of gas atomizing method, water atomizing method, centrifugal force atomizing method may be used.

  In the method for producing a Pd—Cr—W based sputtering target according to the embodiment of the present invention, since the alloy powder is produced by the atomizing method, the raw material metal is once heated to a high temperature to become a molten metal. Alkali metals such as K, alkaline earth metals such as Ca, and gas impurities such as oxygen and nitrogen are volatilized outside and removed. For this reason, the amount of impurities in the obtained alloy powder decreases.

  Therefore, the impurities in the target obtained using the alloy powder obtained by the atomization method are also reduced, for example, the oxygen concentration can be suppressed to 1500 mass ppm or less, and sputtering using the target is good. Become.

  In addition, when it produces by the gas atomization method using argon gas or nitrogen gas, in the obtained alloy powder, oxygen concentration can be restrained lower and it becomes a more favorable raw material powder.

2-2. About the mixed powder In the alloy powder obtained by the atomization method as described above, the average particle size is 10 to 100 μm so that the Cr content is 5 to 50 at% and the W content is 5 to 40 at% with respect to the whole powder. A mixed powder is prepared by mixing Cr powder (preferably 30 to 70 μm) and W powder having an average particle diameter of 4 to 40 μm. The average particle size of the mixed powder is preferably such that the average size of the combined phase of both the Cr phase and the W phase in the obtained target is 3 to 100 μm, and the average particle size of the mixed powder is 2 to 90 μm. It is preferable that

  Here, in order to obtain a good target, it is necessary to reduce impurities such as oxygen, nitrogen, carbon, and sulfur in the Cr powder and W powder. For this purpose, the Cr powder and W powder must be heated in hydrogen. There is. By heating Cr powder and W powder in hydrogen, it is possible to produce Cr powder and W powder with reduced impurities such as oxygen, nitrogen, carbon, and sulfur. Since W powder has high activity and is unstable, if Cr powder has an average particle size of less than 10 μm and W powder has an average particle size of less than 2 μm, there is a risk of explosion and handling is difficult. . On the other hand, when the average particle size of the Cr powder to be mixed exceeds 100 μm, when the obtained target is used to form a film by sputtering, it becomes easy to segregate Cr in the film. If the average particle diameter of the W powder to be mixed is larger than 40 μm, it is difficult to obtain uniform erosion when performing sputtering using the target obtained.

  Even when the Cr content and the W content are 5 to 50 at% and the W content is 5 to 40 at% with respect to the entire mixed powder, the Cr and W contents are 5 to 5% with respect to the entire target, respectively. 50 at% and 5 to 40 at%. For this reason, the crystal structure of Pd in the intermediate layer formed by sputtering using the target approaches the hexagonal close-packed structure (hcp) of Ru, and a recording layer with a good c-axis orientation is formed on the intermediate layer. (Magnetic layer) can be formed.

  In the manufacturing method of the present embodiment, the atomized alloy powder is mixed with Cr powder and W powder to form a mixed powder and then formed into a target. However, molding is performed using only the alloy powder obtained by the atomizing method. You can also get a target. Specifically, for example, a molten alloy is prepared so that the Cr content is 0 to 35 at%, the W content is 0 to 22 at%, and the balance is Pd and unavoidable impurities, and the injection temperature is 1600 to 2100 ° C. Atomization is performed to obtain an alloy powder, and the target can be obtained by molding only with the alloy powder by a molding method described later (Reference Example 1 described later corresponds). However, in this case, only targets with Cr and W contents of 0 to 35 at% and 0 to 22 at%, respectively, with respect to the entire target can be produced.

  On the other hand, in the manufacturing method of this embodiment, the Cr powder and the W are added to the alloy powder obtained by the atomizing method so that the Cr content is 5 to 50 at% and the W content is 5 to 40 at% with respect to the whole powder. The powder is mixed to produce a mixed powder, and the obtained mixed powder is molded by a molding method described later to obtain a target. Thus, the Cr and W contents relative to the entire target are 5 to 50 at% and 5 to 5, respectively. A target of 40 at% can be manufactured.

2-3. Forming Method The method for forming the mixed powder by heating under pressure is not particularly limited. For example, a hot pressing method, a hot isostatic pressing method (HIP method), a discharge plasma sintering method (SPS method), etc. Can be used.

  Regardless of which molding method is used, if the sintering temperature is too low, the density of the sintered body will not increase. On the other hand, if the sintering temperature is too high, carbon will enter from the mold used for sintering. There is a fear. For this reason, 1000-1500 degreeC is preferable for sintering temperature, More preferably, it is 1200-1400 degreeC.

When the hot press method is used, the pressure during sintering is preferably 10 MPa or more, more preferably 15 MPa or more, from the viewpoint of sufficiently increasing the density of the sintered body. In addition, if the sintering time is too short, the density of the sintered body does not sufficiently increase. On the other hand, if the sintering time is too long, the structure becomes coarse, so 30 to 120 min is preferable, and 45 to 90 min is more preferable. Further, the atmosphere is preferably 1 × 10 ⁻¹ Pa or less, more preferably 5 × 10 ⁻² Pa or less, from the viewpoint of lowering the oxygen concentration in the obtained sintered body.

  However, since the amount of impurities in the target obtained can be reduced by forming using the discharge plasma sintering method (SPS method), the forming is performed using the discharge plasma sintering method (SPS method). It is more preferable. In spark plasma sintering, plasma is generated between powder particles during the sintering process, and oxygen, nitrogen, and the like adsorbed on the powder can be quickly dissociated. The amount of impurities in the target obtained by molding the mixed powder using the discharge plasma sintering method (SPS method) is, for example, an oxygen concentration of 400 mass ppm or less, a nitrogen concentration of 100 mass ppm or less, carbon The concentration can be suppressed to 200 mass ppm or less, and the sulfur concentration can be suppressed to 50 mass ppm or less.

3. About Effect The Pd—Cr—W based sputtering target according to the embodiment of the present invention is composed of the components and structure as described above, and can be a substitute for the ruthenium target. Furthermore, the target according to the present embodiment is inexpensive because it uses an inexpensive material and can be manufactured by an inexpensive manufacturing method without using a special method.

  As described above, the reason why the target according to the present embodiment can be manufactured at low cost is that Cr is contained in an alloy matrix containing 0 to 35 at%, W is contained in 0 to 22 at%, and the balance is Pd and inevitable impurities. This is because a structure in which at least one of the phases and the W phase is dispersed is formed. By adopting such a structure, the content of Cr in the atomized alloy powder used for production is, for example, 35 at. Even if the W content is, for example, 22 at% or less, a target having a Cr content of 5 to 50 at% and a W content of 5 to 40 at% can be produced efficiently and economically. Can be manufactured.

4). Since the layer formed using the Pd—Cr—W based sputtering target according to the present embodiment approximates the crystal structure of ruthenium, this Pd—Cr—W based sputtering target is used for a magnetic recording medium. It is suitable for producing an intermediate layer, particularly an intermediate layer of a perpendicular magnetic recording medium. However, the Pd—Cr—W-based sputtering target according to the present embodiment is not limited to the use of producing a magnetic recording medium, and can be used for uses other than the production of a magnetic recording medium as long as the ruthenium layer is used. be able to.

Example 1
Each metal was weighed so that the alloy composition would be Pd: 95 at%, W: 5 at%, heated to 1850 ° C. to form a Pd—W alloy melt, and gas atomized at an injection temperature of 1850 ° C. to produce a Pd-5 at% W alloy A powder was prepared. It was 50 micrometers when the average particle diameter of the produced alloy powder was measured by Microtrack MT3000 made by Nikkiso Co., Ltd.

  To the obtained Pd-5 at% W alloy powder, Cr powder having an average particle size of 63 μm was added so that the Cr content was 20 at% with respect to the whole powder, and the W content was with respect to the whole powder. W powder having an average particle diameter of 30 μm was added so as to be 20 at%, and mixed with a ball mill for 4 hours to prepare a mixed powder. The added Cr powder was 20 at% with respect to the entire mixed powder, and the added W powder was 16 at% with respect to the entire mixed powder.

The produced mixed powder was hot pressed under the conditions of a temperature of 1300 ° C., a pressure of 20 MPa, a time of 45 min, and an atmosphere of 5 × 10 ⁻² Pa or less to obtain a sintered body. It was 12.3 (g / cm < ³ >) when the density of the obtained sintered compact was measured by the Archimedes method. Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 96.1%.

  Moreover, the cross section of the obtained sintered compact was observed with the metal microscope. FIG. 2 shows a photograph taken with a metal microscope. In FIG. 2, the dark portion is the W phase, and the light portion is the Pd-5 at% W alloy, and the obtained sintered body has a Cr phase and a W phase in the Pd-5 at% W alloy matrix. It can be seen that has a dispersed structure.

  In addition, draw a straight line on a metal microscope photograph at a magnification of 140 times and measure the length of all the parts where the straight line overlaps the combined phase of both Cr and W phases. By calculating the average value, the average size of the combined phase of both the Cr phase and the W phase was determined to be 40 μm. The number of parallel straight lines drawn on the metallurgical micrograph is the number that overlaps with the combined phase of both the Cr phase and the W phase at 200 or more, and in this example, in the direction parallel to the longitudinal direction of the metal micrograph. Twenty straight lines were drawn at random intervals.

  Next, the obtained sintered body was processed into a diameter of 180 mm and a thickness of 7 mm to obtain a sputtering target. About the obtained sputtering target, when oxygen concentration was measured with the TC-600 type | mold oxygen-nitrogen simultaneous analyzer made from LECO, it was 229 mass ppm.

  Next, sputtering was performed using a sputtering apparatus manufactured by Canon Anelva Co., Ltd. using the obtained sputtering target to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer. In the evaluation of the recording characteristics of the hard disk in Example 1, the following Examples 2 to 10, and Comparative Examples 1 to 3, the case where there is no difference in the recording characteristics compared to the hard disk using ruthenium Ru in the intermediate layer is Table 1 shows the case where the recording characteristics are inferior to that of a hard disk using ruthenium Ru for the intermediate layer as x.

(Example 2)
Each metal was weighed so that the alloy composition would be Pd: 75 at%, Cr: 25 at%, heated to 1650 ° C. to form a Pd—W alloy melt, and gas atomized at an injection temperature of 1650 ° C. to obtain a Pd-25 at% Cr alloy A powder was prepared. When the average particle diameter of the produced alloy powder was measured in the same manner as in Example 1, it was 50 μm.

  To the obtained Pd-25 at% Cr alloy powder, W powder having an average particle size of 30 μm was added so that the W content was 20 at% with respect to the whole powder, and mixed in a ball mill for 4 hours as in Example 1. Thus, a mixed powder was produced. The added W powder was 20 at% based on the entire mixed powder.

The produced mixed powder was hot pressed under the same conditions as in Example 1 except that the hot press temperature was 1335 ° C., to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.3 (g / cm ³ ). Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 96.1%.

  Further, the cross section of the obtained sintered body was observed with a metal microscope in the same manner as in Example 1. FIG. 3 shows a photograph taken with a metal microscope. In FIG. 3, the dark portion is the W phase, and the light portion is the Pd-25 at% Cr alloy, and in the obtained sintered body, the W phase was dispersed in the Pd-25 at% Cr alloy matrix. It can be seen that it has a structure. Moreover, when the average size of the phase which combined both Cr phase and W phase was calculated | required like Example 1, it was 32 micrometers.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, when oxygen concentration was measured like Example 1, it was 345 mass ppm.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Example 3)
Each metal was weighed so that the alloy composition would be Pd: 71.2 at%, Cr: 23.8 at%, W: 5 at% and heated to 1850 ° C. to form a molten Pd—Cr—W alloy, injection temperature 1850 ° C. Then, gas atomization was performed to prepare a Pd-23.8 at% Cr-5 at% W alloy powder. When the average particle diameter of the produced alloy powder was measured in the same manner as in Example 1, it was 50 μm.

  W powder having an average particle diameter of 30 μm was added to the obtained Pd-23.8 at% Cr-5 at% W alloy powder so that the W content was 20 at% with respect to the entire powder, and the same as in Example 1. And mixed with a ball mill for 4 hours to prepare a mixed powder. The added W powder was 15.8 at% with respect to the entire mixed powder.

The produced mixed powder was hot pressed under the same conditions as in Example 2 to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.5 (g / cm ³ ). Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 97.7%.

  Further, the cross section of the obtained sintered body was observed with a metal microscope in the same manner as in Example 1. FIG. 4 shows a photograph taken with a metal microscope. In FIG. 4, the dark part is the W phase, the light part is Pd-23.8 at% Cr-5 at% W alloy, and the obtained sintered body is Pd-23.8 at% Cr- It can be seen that the W phase is dispersed in the 5 at% W alloy matrix. Moreover, when the average size of the phase which combined both Cr phase and W phase was calculated | required similarly to Example 1, it was 28 micrometers.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, when oxygen concentration was measured like Example 1, it was 678 mass ppm.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

Example 4
Each metal was weighed so that the alloy composition would be Pd: 67.5 at%, Cr: 22.5 at%, W: 10 at% and heated to 1900 ° C. to form a Pd—Cr—W alloy melt, injection temperature 1900 ° C. Gas atomization was performed to prepare a Pd-22.5 at% Cr-10 at% W alloy powder. When the average particle diameter of the produced alloy powder was measured in the same manner as in Example 1, it was 50 μm.

  To the obtained Pd-22.5 at% Cr-10 at% W alloy powder, W powder having an average particle diameter of 30 μm was added so that the W content was 20 at% with respect to the entire mixed powder. Similarly, a mixed powder was prepared by mixing for 4 hours in a ball mill. The added W powder was 11.1 at% with respect to the entire mixed powder.

The produced mixed powder was hot pressed under the same conditions as in Example 2 to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.5 (g / cm ³ ). Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 97.7%.

  Further, the cross section of the obtained sintered body was observed with a metal microscope in the same manner as in Example 1. FIG. 5 shows a photograph taken with a metal microscope. In FIG. 5, the dark part is the W phase, the light part is Pd-22.5 at% Cr-10 at% W alloy, and the obtained sintered body is Pd-22.5 at% Cr- It can be seen that the W phase is dispersed in the 10 at% W alloy matrix. Moreover, when the average size of the phase which combined both Cr phase and W phase was calculated | required like Example 1, it was 31 micrometers.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, when oxygen concentration was measured like Example 1, it was 339 mass ppm.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Example 5)
A mixed powder was produced in the same manner as in Example 4 except that the average particle size of the W powder added to the Pd-22.5 at% Cr-10 at% W alloy powder produced by the atomization method was 12 μm. The produced mixed powder was hot pressed under the same conditions as in Example 4 to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.3 (g / cm ³ ). Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 96.1%.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, it was 751 mass ppm when the oxygen concentration was measured similarly to Example 1. FIG.

  Further, when the average size of the combined phase of both the Cr phase and the W phase was determined in the same manner as in Example 1, it was 15 μm.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Example 6)
A mixed powder was produced in the same manner as in Example 4 except that the average particle diameter of the W powder added to the Pd-22.5 at% Cr-10 at% W alloy powder produced by the atomization method was 4 μm. The produced mixed powder was hot pressed under the same conditions as in Example 4 to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.4 (g / cm ³ ). Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 96.9%.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, when oxygen concentration was measured similarly to Example 1, it was 1120 mass ppm.

  Moreover, when the average size of the phase which combined both Cr phase and W phase was calculated | required like Example 1, it was 6 micrometers.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Example 7)
A mixed powder was produced in the same manner as in Example 4 except that the average particle diameter of the W powder added to the Pd-22.5 at% Cr-10 at% W alloy powder produced by the atomization method was 2 μm. The produced mixed powder was hot pressed under the same conditions as in Example 4 to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.3 (g / cm ³ ). Since the theoretical density was 12.8 (g / cm ³ ), the relative density was 96.1%.

  Further, the cross section of the obtained sintered body was observed with a metal microscope in the same manner as in Example 1. FIG. 6 shows a photograph taken with a metal microscope. In FIG. 6, the dark part is the W phase, the light part is Pd-22.5 at% Cr-10 at% W alloy, and the obtained sintered body is Pd-22.5 at% Cr— It can be seen that the W phase is dispersed in the 10 at% W alloy matrix. Moreover, it turns out that the structure | tissue is fine compared with Examples 1-4 (FIGS. 2-5).

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. With respect to the obtained sputtering target, the oxygen concentration was measured in the same manner as in Example 1. As a result, it was 2187 mass ppm.

  Further, when the average size of the combined phase of both the Cr phase and the W phase was determined in the same manner as in Example 1, it was 3 μm.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Example 8)
Each metal is weighed so that the alloy composition is Pd: 60 at%, Cr: 35 at%, W: 5 at%, heated to 1850 ° C. to form a Pd—W alloy melt, gas atomized at an injection temperature of 1850 ° C., and Pd A −35 at% Cr-5 at% W alloy powder was produced. When the average particle diameter of the produced alloy powder was measured in the same manner as in Example 1, it was 50 μm.

  To the obtained Pd-35 at% Cr-5 at% W alloy powder, Cr powder having an average particle size of 63 μm is added so that the Cr content is 50 at% with respect to the whole powder, and the W content is powder. W powder having an average particle size of 30 μm was added so as to be 40 at% with respect to the whole, and mixed with a ball mill for 4 hours to prepare a mixed powder. The added Cr powder was 44.2 at% with respect to the entire mixed powder, and the added W powder was 39.2 at% with respect to the entire mixed powder.

The produced mixed powder was hot pressed under the same conditions as in Example 1 except that the hot press temperature was 1350 ° C., to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.73 (g / cm ³ ). Since the theoretical density was 13.25 (g / cm ³ ), the relative density was 96.1%.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, when oxygen concentration was measured like Example 1, it was 535 mass ppm.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

Example 9
Each metal was weighed so that the alloy composition would be Pd: 60 at%, Cr: 30 at%, W: 10 at%, heated to 1900 ° C. to form a Pd—W alloy melt, gas atomized at an injection temperature of 1900 ° C., and Pd A -30 at% Cr-10 at% W alloy powder was produced. When the average particle diameter of the produced alloy powder was measured in the same manner as in Example 1, it was 50 μm.

  To the obtained Pd-30 at% Cr-10 at% W alloy powder, W powder having an average particle size of 30 μm was added so that the W content was 40 at% with respect to the whole powder, and mixed for 4 hours by a ball mill. A mixed powder was prepared. The added W powder was 33.3 at% based on the entire mixed powder.

The produced mixed powder was hot pressed under the same conditions as in Example 1 except that the hot press temperature was 1350 ° C., to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 13.86 (g / cm ³ ). Since the theoretical density was 14.36 (g / cm ³ ), the relative density was 96.5%.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. With respect to the obtained sputtering target, the oxygen concentration was measured in the same manner as in Example 1. As a result, it was 953 mass ppm.

  Next, using the obtained sputtering target, sputtering was performed in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Reference Example 1)
Each metal is weighed so that the alloy composition is Pd: 90 at%, Cr: 5 at%, W: 5 at%, heated to 1850 ° C. to form a molten Pd—Cr—W alloy, and gas atomization is performed at an injection temperature of 1850 ° C. Thus, a Pd-5 at% Cr-5 at% W alloy powder was produced. When the average particle diameter of the produced alloy powder was measured in the same manner as in Example 1, it was 50 μm.

In Examples 1 to 9, a mixed powder was prepared by adding a Cr powder and / or a W powder to an alloy powder obtained by atomization (hereinafter sometimes referred to as an atomized powder). However, in Reference Example 1, neither the Cr powder nor the W powder was added to the atomized powder, and only the atomized powder was hot pressed to obtain a sintered body. It has gained. The hot pressing conditions are the same as in Example 1 except that the hot pressing temperature is 1220 ° C. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.09 (g / cm ³ ). Since the theoretical density was 12.22 (g / cm ³ ), the relative density was 98.9%.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, it was 185 mass ppm when the oxygen concentration was measured like Example 1. FIG.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, there was no difference in recording characteristics as compared with the hard disk using ruthenium Ru for the intermediate layer.

(Comparative Example 1)
Gas atomization is performed to produce a Pd-25 at% W alloy powder, and Cr powder is added to the produced alloy powder (atomized powder) to produce a Pd-20 at% Cr-20 at% W alloy powder. Attempts were made to obtain a sintered body.

  However, each metal was weighed so that the alloy composition would be Pd: 75 at% and W: 25 at% and heated to 2100 ° C., but it did not melt and could not obtain a molten alloy, and an atomized powder could be obtained. There wasn't. For this reason, hot pressing was not performed and a target could not be obtained.

(Comparative Example 2)
Gas atomization was performed to produce a Pd-20 at% Cr-25 at% W alloy powder, and an attempt was made to obtain a sintered body by hot pressing only the produced alloy powder (atomized powder).

  However, each metal was weighed so that the alloy composition would be Pd: 55 at%, Cr: 20 at%, W: 25 at%, and heated to 2100 ° C., but it did not melt and could not obtain a molten alloy. Could not get. For this reason, the hot press was not performed and the target could not be obtained.

(Comparative Example 3)
Without atomizing powder by gas atomization, Pd powder (average particle size 50 μm), Cr powder (average particle size 63 μm), and W powder (average particle size 30 μm), which are not atomized powders, are mixed in a ball mill for 4 hours. Thus, a Pd-20 at% Cr-20 at% W mixed powder was produced. The produced mixed powder was hot pressed under the same conditions as in Example 2 to obtain a sintered body. When the density of the obtained sintered body was measured in the same manner as in Example 1, it was 12.02 (g / cm ³ ). Since the theoretical density was 12.79 (g / cm ³ ), the relative density was 94.0%.

  Next, the obtained sintered body was processed in the same manner as in Example 1 to obtain a sputtering target. About the obtained sputtering target, it was 4530 mass ppm when the oxygen concentration was measured similarly to Example 1. FIG.

  Next, sputtering was performed using the obtained sputtering target in the same manner as in Example 1 to form the intermediate layer shown in FIG. 1, and a hard disk having the structure shown in FIG. 1 was produced. When the recording characteristics of the produced hard disk were evaluated, the recording characteristics were inferior to the hard disk using ruthenium Ru as the intermediate layer, and the recording characteristics were inferior to the hard disks in Examples 1-9.

  In Examples 1 to 10 in which the content ratios of the respective metals are within the scope of the present invention, the recording characteristics of the obtained hard disk are all the same as those of the hard disk using ruthenium Ru as the intermediate layer and good. Results were obtained.

  On the other hand, Comparative Examples 1 and 2 are weighed so that the content of W is 25 at% as a raw material metal for the molten alloy used for atomized powder production. In the raw material metal for the molten alloy used for atomized powder production, More than 22 at% W is contained. For this reason, although it heated to 2100 degreeC, it did not melt | dissolve, the alloy molten metal could not be obtained, and the atomized powder could not be obtained. For this reason, hot pressing was not performed and a target could not be obtained. In order to obtain a molten alloy from the raw metal weighed in Comparative Examples 1 and 2 and perform atomization, it is considered necessary to heat to a temperature higher than 2100 ° C.

  In Comparative Example 3, the content ratio of each metal with respect to the entire target is within the scope of the present invention, but both Cr and W are contained, or a mixed powder is prepared using an atomized powder containing Cr. The target obtained by hot pressing has a region of only Pd containing neither Cr nor W. For this reason, it is considered that a good film was not obtained by sputtering.

The figure which shows typically the thickness direction section about an example of the perpendicular magnetic recording system hard disk Metal micrograph of sintered body in Example 1 Metal micrograph of the sintered body in Example 2 Metal micrograph of sintered body in Example 3 Metal micrograph of sintered body in Example 4 Metal micrograph of sintered body in Example 7

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Hard disk 102 ... Base material 104 ... Soft magnetic backing layer 106 ... Intermediate | middle layer 108 ... Recording layer (magnetic layer)

Claims (14)

A Pd—Cr—W based sputtering target containing Pd, Cr, W as main components,
The target having a structure in which at least one of Cr and W phases is dispersed in an alloy matrix containing at least one of Cr and W, with the balance being Pd and inevitable impurities. A Pd—Cr—W-based sputtering target, wherein the Cr content is 5 to 50 at% and the W content is 5 to 40 at%. In claim 1,
The Pd—Cr—W based sputtering target, wherein the alloy matrix contains 0 to 35 at% of Cr and 0 to 22 at% of W. In claim 1 or 2,
The Pd—Cr—W based sputtering target, wherein the average size of the combined phase of both the Cr phase and the W phase in the Pd—Cr—W based sputtering target is 3 to 100 μm. In any one of Claims 1-3,
An oxygen concentration in the Pd—Cr—W based sputtering target is 1500 ppm by mass or less, and a Pd—Cr—W based sputtering target. In any one of Claims 1-4,
A Pd—Cr—W-based sputtering target characterized by being for a magnetic recording medium.   An alloy powder containing at least one of Cr and W, the balance being Pd and inevitable impurities is prepared by an atomizing method, and the content of Cr with respect to the entire powder is 5 to 50 at%. The mixed powder is prepared by mixing at least one of the Cr powder and the W powder so that the W content is 5 to 40 at%, and then the prepared mixed powder is heated under pressure. A method for producing a Pd—Cr—W-based sputtering target, comprising molding. In claim 6,
The said alloy powder produced by the atomizing method contains 0 to 35 at% of Cr, and 0 to 22 at% of W, The manufacturing method of the Pd-Cr-W type | system | group sputtering target characterized by the above-mentioned. In claim 6 or 7,
The method for producing a Pd—Cr—W based sputtering target, wherein the average size of the combined phase of both the Cr phase and the W phase in the Pd—Cr—W based sputtering target is 3 to 100 μm. In any one of Claims 6-8,
The manufacturing method of the Pd-Cr-W type | system | group sputtering target characterized by making oxygen concentration in the obtained Pd-Cr-W type | system | group sputtering target into 1500 mass ppm or less. In any one of Claims 6-9,
The atomizing method is performed using argon gas or nitrogen gas. A method for producing a Pd—Cr—W-based sputtering target. In any one of Claims 6-10,
The atomizing method is performed at a spraying temperature of 1600 to 2100 ° C. A method for producing a Pd—Cr—W based sputtering target. In any one of Claims 6-11,
A method for producing a Pd—Cr—W sputtering target, wherein the produced mixed powder is molded by a discharge plasma sintering method. In any one of Claims 6-12,
The obtained Pd—Cr—W-based sputtering target is for magnetic recording media, and a method for producing a Pd—Cr—W-based sputtering target.   A Pd—Cr—W-based sputtering target produced by the production method according to claim 6.