JP2019116682A - Ruthenium/rhenium-containing sputtering target, ruthenium/rhenium-containing layer, and manufacturing method therefor - Google Patents

Abstract

To provide a ruthenium/rhenium-containing sputtering target capable of improving crystal orientation tissue, crystal magnetic anisotropy and magnetic coercive force of a ruthenium/rhenium-containing intermediate layer.SOLUTION: A ruthenium/rhenium-containing sputtering target includes ruthenium, rhenium and carbon, and contains, based upon the total weight of the ruthenium/rhenium-containing sputtering target, 0.1-45 wt.% of ruthenium, 0.003-0.01 wt.% of carbon, and rhenium for the rest. The components of the ruthenium/rhenium-containing sputtering target are controlled to control components of a ruthenium/rhenium-containing layer produced by sputtering from the target as well, and the ruthenium/rhenium-containing layer can be improved in crystallinity and fineness in crystal grain size.SELECTED DRAWING: Figure 1B

Description

  The present invention relates to a sputtering target containing ruthenium / rhenium, a layer containing ruthenium / rhenium, and a method for producing a sputtering target containing the ruthenium / rhenium.

  With the increasing demand for data storage capacity of people's magnetic recording media, what has become a research topic that manufacturers are actively developing consistently is how to make the recording quality of magnetic recording media Improve it. In the prior art, the magnetic recording density of the magnetic recording medium is improved by the miniaturization of the recording unit and the superposition of the vertical layered structure.

  Usually, the layered structure of the perpendicular magnetic recording medium is, from bottom to top, a substrate, an adhesion layer, a soft underlayer, a seed layer, a seed layer, an intermediate layer, a magnetic recording layer (magnetic). recording layer), a cap layer and a lubricating layer.

  The function of the intermediate layer in the perpendicular magnetic recording medium is to assist the crystalline orientation texture of the magnetic crystal grains of the recording layer of the perpendicular magnetic recording medium and to control the grain size of the magnetic crystal grains, and the current intermediate The layer is mainly composed of ruthenium or an alloy of ruthenium, and the addition of other materials helps to stabilize the structure of hexagonal close packed (HCP), which leads to the growth of preferential grains. Maintain the direction.

  In order to improve the magnetic recording density, the size of the crystal grains in the recording layer must always be reduced, which causes the magnetic coercivity (Hc) and the magnetocrystalline anisotropy constant (Ku) of the recording layer to be reduced. While improving the uniformity of the magnetic exchange decoupling of the recording layer and reducing the bit error ratio (BER), and the signal to noise ratio of the recording medium (signal to noise ratio). , SNR) and areal recording density.

  However, regarding the recording layer, the crystalline orientation structure obtained by the intermediate layer formed of the above-mentioned material containing ruthenium or ruthenium alloy, the improvement effect of the magnetocrystalline anisotropy and the magnetic coercivity are still insufficient, and the high density at the present time It has not been possible to meet the requirements for magnetic recording media.

  In view of the above problems, the present invention aims to provide a sputtering target containing ruthenium / rhenium, which is applied to sputtering to have more excellent ruthenium (002) crystallinity and refined crystal grains A layer containing ruthenium / rhenium can be formed.

  In order to achieve the above object, the sputtering target containing ruthenium / rhenium according to the present invention contains ruthenium (Ru), rhenium (Re) and carbon (C) and is based on the total weight of the entire sputtering target containing ruthenium / rhenium. The content of the rhenium component is 0.1 wt% to 45 wt%, the content of the carbon component is 0.003 wt% to 0.01 wt%, and the remaining component is ruthenium.

  By the above technical means, the present invention can control the constituents of the ruthenium / rhenium-containing layer further by controlling the constituents of the ruthenium / rhenium-containing sputtering target, and thereby the ruthenium / rhenium-containing layer It is possible to realize improvement in the crystallinity of ruthenium (002) and refinement of the grain size of the ruthenium / rhenium-containing layer.

  Preferably, the sputtering target containing ruthenium / rhenium includes the additive component (M1), and the additive component is cobalt (Co), chromium (Cr), tungsten (W), titanium (Ti), tantalum (Ta), The content of the additional component is selected from the group consisting of boron (B), palladium (Pd) and a composition thereof, and is greater than 0% by weight based on the total weight of the entire sputtering target containing ruthenium / rhenium, Up to 60 weight percent. More preferably, the content of the above-mentioned added component is 10 weight percent to 40 weight percent based on the total weight of the entire sputtering target containing ruthenium / rhenium. Even more preferably, the content of the additive component is 20% by weight to 30% by weight based on the total weight of the entire sputtering target containing ruthenium / rhenium.

  Preferably, the sputtering target containing ruthenium / rhenium contains an oxide (M2), and the oxide is silicon dioxide, titanium dioxide, chromium trioxide, boron trioxide, tantalum pentoxide, cobalt monoxide, trioxide The oxide content is greater than 0 weight percent and 40 weight based on the total weight of the entire sputtering target comprising ruthenium / rhenium selected from the group consisting of dicobalt oxide, tungsten trioxide and compositions thereof It is up to a percentage. More preferably, the content of the oxide is 5% by weight to 35% by weight based on the total weight of the entire sputtering target containing ruthenium / rhenium.

In embodiments therein, the sputtering target comprising ruthenium / rhenium present invention may be a _Ru x _Re a _{C b} sputtering _target, based on the total weight of the whole Ru x _Re a _{C b} sputtering target of Ru The content (i.e., x in the above composition formula) is 54.99 weight percent to 99 weight percent.

In another embodiment, a sputtering target comprising ruthenium / rhenium present invention may be a _Ru x _Re a _C b M1 _c sputtering _target, based on the total weight of Ru _x Re _a C b M1 _c overall sputtering target The content of Ru is 10% by weight to 99% by weight, and the content of M1 (i.e., c in the above composition formula) is greater than 0% by weight and up to 60% by weight. Preferably, the content of Ru is 15 weight percent to 89 weight percent, and the content of M1 is 10 weight percent to 40 weight percent. More preferably, the content of Ru is 25 weight percent to 79 weight percent, and the content of M1 is 20 weight percent to 30 weight percent.

In yet another embodiment, a sputtering target comprising ruthenium / rhenium present invention may be a _Ru x _Re a _C b M2 _d sputtering _target, Ru _x Re _a C b M2 _d sputtering target total based on the total weight The content of Ru is from 15 to 99 weight percent, and the content of M 2 (ie, d in the above composition formula) is greater than 0 and up to 40 weight percent. Preferably, the content of Ru is 25 weight percent to 94 weight percent, and the content of M 2 is 5 weight percent to 35 weight percent.

In yet another embodiment, a sputtering target comprising ruthenium / rhenium present invention may be a _{Ru x Re a C b M1 c} M2 d sputtering _{target, Ru x Re a C b M1 c} M2 d sputtering target overall Based on the total weight, the content of Ru is 10 wt% to 99 wt%, the content of M1 is more than 0 wt%, the content of M2 is more than 0 wt%, the content of M2 is 40 wt% I assume. Preferably, the content of Ru is 10% by weight to 89% by weight, the content of M1 is 10% by weight to 40% by weight, and the content of M2 is more than 0% by weight and up to 40% by weight. More preferably, the content of Ru is 10 wt% to 79 wt%, the content of M1 is 20 wt% to 30 wt%, and the content of M2 is more than 0 wt% to 40 wt%. Even more preferably, the content of Ru is 10 wt% to 74 wt%, the content of M1 is 20 wt% to 30 wt%, and the content of M2 is 5 wt% to 35 wt%.

The method of the present invention for producing a sputtering target containing ruthenium / rhenium includes the following procedures.
Prepare all the raw powder. The raw material powder contains ruthenium, rhenium and carbon, and the content of the rhenium is 0.1 weight percent to 45 weight percent based on the total weight of the whole raw material powder, and the carbon content is 0. 003 weight percent to 0.01 weight percent, and the remaining component is ruthenium.
The raw material powder is sintered at a temperature of 800 ° C. to 1300 ° C. to obtain a sputtering target containing the ruthenium / rhenium.

Preferably, the raw material powder is an element powder, a pre-alloy powder, or a mixture thereof, and the element powder may be ruthenium powder, rhenium powder, carbon powder, or a powder of other elements, and the pre-alloy powder is ruthenium. It may be a pre-alloy powder containing rhenium, a pre-alloy powder containing ruthenium / carbon, a pre-alloy powder containing rhenium / carbon, or a pre-alloy powder containing ruthenium / rhenium / carbon, but not limited thereto. In the embodiment among them, the raw material powder can be a combination of various element powders. For example, the raw material powder can be a combination of ruthenium powder, rhenium powder and carbon powder.
In another embodiment, the raw material powder can be a combination of at least two or more kinds of pre-alloy powders, for example, the raw material powder is a combination of a pre-alloy powder containing ruthenium / rhenium and a pre-alloy powder containing ruthenium / carbon. The raw material powder may be a combination of a prealloyed powder containing ruthenium / carbon and a prealloyed powder containing rhenium / carbon, or the raw material powder may be a prealloyed powder containing ruthenium / rhenium, ruthenium / carbon It may be a combination of a pre-alloyed powder comprising and a pre-alloyed powder comprising rhenium / carbon, but is not limited thereto. Alternatively, the raw material powder can be one single kind of pre-alloy powder, and for example, the raw material powder can be a pre-alloy powder containing ruthenium / rhenium / carbon.
In yet another embodiment, the raw material powder may be a mixture of elemental powder and prealloyed powder, for example, the raw material powder may be a combination of ruthenium / rhenium containing prealloyed powder and carbon powder, It shall not be restricted to this.

  Preferably, the raw material powder contains an additive component, and the additive component is selected from the group consisting of cobalt, chromium, tungsten, titanium, tantalum, boron, palladium and a composition thereof, and the entire sputtering target containing ruthenium / rhenium. Based on the total weight, the content of the above-mentioned additive components is more than 0% by weight and up to 60% by weight. More preferably, the content of the above-mentioned added component is 10 weight percent to 40 weight percent based on the total weight of the entire sputtering target containing ruthenium / rhenium. Even more preferably, the content of the additive component is 20% by weight to 30% by weight based on the total weight of the entire sputtering target containing ruthenium / rhenium.

  Preferably, the raw material powder contains an oxide, and the oxide is silicon dioxide, titanium dioxide, chromium trioxide, diboron trioxide, tantalum pentoxide pentoxide, cobalt monoxide, cobalt trioxide, tungsten trioxide and the like. The content of the oxide is selected from the group consisting of the composition and based on the total weight of the entire sputtering target containing ruthenium / rhenium to be greater than 0 weight percent and up to 40 weight percent. More preferably, the content of the oxide is 5% by weight to 35% by weight based on the total weight of the entire sputtering target containing ruthenium / rhenium.

  Specifically, the following contents can be separately included in the procedure for preparing all the raw material powders. The raw material powder is polished to form a powder after polishing. Next, the powder after polishing is pre-pressed at a pressure of 10 bar to 500 bar to form a green compact, and a sintering reaction is performed on the green compact.

  Specifically, the sintering method may be hot pressing (HP), hot isostatic pressing (HIP), or spark plasma sintering (SPS) Although it can be, it shall not be restricted to the above. When sintering is performed by a hot press method (HP), the sintering can be performed at a temperature of 1000 ° C. to 1300 ° C. and a pressure of 200 bar to 600 bar. When sintering is performed by hot isostatic pressing (HIP), sintering can be performed at a temperature of 1000 ° C. to 1300 ° C. and a pressure of 1000 bar to 2000 bar. When sintering is performed by spark plasma sintering (SPS), the sintering can be performed at a temperature of 800 ° C. to 1200 ° C. and a pressure of 300 bar to 1000 bar.

  The invention also provides a layer comprising ruthenium / rhenium. The layer containing ruthenium / rhenium contains ruthenium, rhenium and carbon, and based on the total weight of the layer containing ruthenium / rhenium, the content of rhenium is 0.1 wt% to 45 wt%, The content is made 0.003 weight percent to 0.01 weight percent, the remaining component is ruthenium, and the average grain size is less than 10 nm in the ruthenium / rhenium containing layer.

  Preferably, the ruthenium / rhenium containing layer is generated from the above-mentioned ruthenium / rhenium containing sputtering target, and the ruthenium / rhenium containing layer contains the above ruthenium / rhenium containing sputtering target. It should be similar to the ingredients. According to the above technical means, the ruthenium / rhenium-containing layer of the present invention can not only obtain excellent crystallinity, but also can refine the grain size of the ruthenium / rhenium-containing layer. As a result, when the ruthenium / rhenium-containing layer of the present invention is used as the intermediate layer of the perpendicular magnetic recording medium, the crystal orientation structure deposited in the recording layer above the intermediate layer can be assisted, and To improve the magnetic recording density of the magnetic recording medium including the layer containing ruthenium / rhenium of this kind.

  Preferably, the layer containing ruthenium / rhenium contains an additive, and the additive is selected from the group consisting of cobalt, chromium, tungsten, titanium, tantalum, boron, palladium and a composition thereof, and ruthenium / rhenium Based on the total weight of the entire layer, the content of the above-mentioned additive components is more than 0% by weight and up to 60% by weight. More preferably, the content of the above-mentioned additive component is 10 weight percent to 40 weight percent based on the total weight of the entire layer containing ruthenium / rhenium. Even more preferably, the content of the above-mentioned additive component is 20 weight percent to 30 weight percent based on the total weight of the entire layer containing ruthenium / rhenium.

  Preferably, the layer containing ruthenium / rhenium contains an oxide, and the oxide is silicon dioxide, titanium dioxide, chromium trioxide, diboron trioxide, tantalum pentoxide, cobalt monoxide, cobalt trioxide, The oxide content is selected from the group consisting of tungsten trioxide and its composition, based on the total weight of the ruthenium / rhenium-containing layer, to be greater than 0 weight percent and up to 40 weight percent. More preferably, the content of the oxide is 5% by weight to 35% by weight based on the total weight of the entire layer containing ruthenium / rhenium.

Specifically, in embodiments therein, a layer containing ruthenium / rhenium present invention may be a _Ru x _Re a _{C b layer,} based on the total weight of the whole Ru x _Re a _{C b} layer The content of Ru (that is, x in the above composition formula) is 54.99% by weight to 99% by weight.

In another embodiment, the layer containing ruthenium / rhenium present invention may be a _Ru x _Re a _C b M1 _{c layer,} based on the total weight of the whole Ru _x Re _a C b M1 _c layer, a Ru The content is 10% by weight to 99% by weight, and the content of M1 is more than 0% by weight and up to 60% by weight. Preferably, the content of Ru is 15 weight percent to 89 weight percent, and the content of M1 is 10 weight percent to 40 weight percent. More preferably, the content of Ru is 25 weight percent to 79 weight percent, and the content of M1 is 20 weight percent to 30 weight percent.

In yet another embodiment, the layer containing ruthenium / rhenium present invention may be a _Ru x _Re a _C b M2 _{d layer,} based on the total weight of the whole Ru _x Re _a C b M2 _d layer, Ru The content of M is from 15% by weight to 99% by weight, and the content of M2 is from 0% by weight to 40% by weight. Preferably, the content of Ru is 25 weight percent to 94 weight percent, and the content of M 2 is 5 weight percent to 35 weight percent.

In yet another embodiment, the layer containing ruthenium / rhenium present invention may be a _{Ru x Re a C b M1 c} M2 d _layer, the total weight of the whole _{Ru x Re a C b M1 c} M2 d layer The content of Ru is 10 wt% to 99 wt%, the content of M1 is more than 0 wt%, the content of M2 is 60 wt%, and the content of M2 is more than 0 wt% to 40 wt%. Preferably, the content of Ru is 10% by weight to 89% by weight, the content of M1 is 10% by weight to 40% by weight, and the content of M2 is more than 0% by weight and up to 40% by weight. More preferably, the content of Ru is 10 wt% to 79 wt%, the content of M1 is 20 wt% to 30 wt%, and the content of M2 is more than 0 wt% to 40 wt%. Even more preferably, the content of Ru is 10 wt% to 74 wt%, the content of M1 is 20 wt% to 30 wt%, and the content of M2 is 5 wt% to 35 wt%.

The X-ray-diffraction pattern of the layer containing ruthenium / rhenium of Example 1, 2 and Comparative Example 3, 7. The enlarged view in the crystalline substance directional characteristic peak of ruthenium (002) of the X-ray-diffraction pattern of the layer containing ruthenium / rhenium of Example 1, 2 and Comparative Examples 3 and 7. FIG.

In order to verify the influence of the constituents of the sputtering target containing ruthenium / rhenium on the crystallinity and grain size of the ruthenium / rhenium-containing layer generated by sputtering, several types of ruthenium / rhenium having different constituents are used. The sputtering targets involved are listed below as examples to illustrate the practice of the invention.
In addition, sputtering targets of pure ruthenium and other sputtering targets containing ruthenium / rhenium are incorporated as comparative examples, and differences in the characteristics of each example and comparative example will be described. Those skilled in the art should now make various modifications and changes through the contents of this specification without departing from the features and effects that can be achieved by the present invention and the spirit of the present invention. It can be easily understood that the content of the content is implemented or applied.

Examples 1 to 6 Preparation of Ru _x Re _a C _b Sputtering Target

  The sputtering targets containing ruthenium / rhenium of Examples 1 to 6 are basically prepared by adopting a hot press (HP) method, and the specific method is as described below.

  First, based on the constituents of the sputtering target containing ruthenium / rhenium shown in Table 1, appropriate amounts of ruthenium powder, rhenium powder and carbon powder are weighed and mixed to form a raw material powder.

  Next, the raw material powder is ground by a high-speed grinder to form a ground powder, the ground powder is uniformly filled in a graphite mold, and a hydraulic device is applied to a pressure of 20 bar to form a green compact. Do.

  Then, the green compact and the graphite mold are put together in a hot press furnace, and sintering is continued for 3 hours at a sintering temperature of 1000 ° C. to 1300 ° C. and a sintering pressure of 362 bar using a hot press method. After forming a sintered body, the above sintered body is lathe processed by wire cutting and computer numerical control (CNC), and a disc-shaped sputtering target containing ruthenium / rhenium (diameter 2 inch, thickness 3 mm) Get a disk shaped target).

The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Examples 1 to 6 are as described in Table 1. The sputtering target containing ruthenium / rhenium of the present examples 1 to 6 can be shown by Ru _x Re _a C _b .

Examples 7 to 18: Preparation of Ru _x Re _a C _b M 1 _c sputtering target

  The sputtering targets containing ruthenium / rhenium of Examples 7 to 18 are basically prepared by employing a hot isostatic pressing (HIP) method, and the specific method is as described below.

  Although the preparation methods of the sputtering target containing ruthenium / rhenium of Examples 7-18 and Examples 1-6 are similar, the differences are as follows. The raw material powder used in Examples 7 to 18 contains ruthenium, rhenium, carbon and an additive component (M1), and the additive component is cobalt, chromium, tungsten, titanium, tantalum, boron, palladium, or a composition thereof. can do. With respect to the green compact formed with the above raw material powder, sintering is continued for 3 hours at a sintering temperature of 1000 ° C. to 1300 ° C. and a sintering pressure of 1750 bar using a hot press method to form a sintered body Further processing is performed to obtain the sputtering target containing ruthenium / rhenium of each example.

The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Examples 7 to 18 are as described in Table 1. The sputtering target containing ruthenium / rhenium of the present Examples 7 to 18 can indicate this by Ru _x Re _a C _b M1 _c .

Examples 19 to 21: Preparation of Ru _x Re _a C _b M 2 _d sputtering target

  The sputtering targets containing ruthenium / rhenium of Examples 19 to 21 are basically prepared by employing a spark plasma sintering (SPS) method, and the specific method is as described below.

  Although the preparation methods of the sputtering target containing ruthenium / rhenium of Examples 19-21 and Examples 1-6 are similar, the difference is as follows. The raw material powders used in Examples 19 to 21 contain ruthenium, rhenium, carbon and oxides, and the above oxides are silicon dioxide, titanium dioxide, chromium trioxide, boron trioxide, tantalum pentoxide, Cobalt oxide, dicobalt trioxide, tungsten trioxide, or a composition thereof can be used. With respect to the green compact formed with the above raw material powder, sintering is continued for 10 minutes at a sintering temperature of 800 ° C. to 1200 ° C. and a sintering pressure of 500 bar using a discharge plasma sintering method to form a sintered body And further processing to obtain the sputtering target containing ruthenium / rhenium of each example.

The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Examples 19 to 21 are as described in Table 1. The sputtering targets containing ruthenium / rhenium of the present Examples 19 to 21 can show this by Ru _x Re _a C _b M 2 _d .

Examples 22 to 25: Preparation of Ru _x Re _a C _b M 1 _c M 2 _d sputtering target

  The sputtering target containing ruthenium / rhenium of Examples 22 to 25 is basically prepared by employing a discharge plasma sintering method, and the specific method is as described below.

  Although the preparation methods of the sputtering target containing ruthenium / rhenium of Examples 22-25 and Examples 19-21 are similar, the differences are as follows. The raw material powder used in Examples 22 to 25 contains ruthenium, rhenium, carbon, an additive component and an oxide, and the additive component is cobalt, chromium, tungsten, titanium, tantalum, boron, palladium or a composition thereof The oxide can be silicon dioxide, titanium dioxide, chromium trioxide, diboron trioxide, tantalum pentoxide pentoxide, cobalt monoxide, cobalt trioxide, tungsten trioxide, or a composition thereof Can.

The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Examples 22 to 25 are as described in Table 1. The sputtering target containing ruthenium / rhenium of Examples 22 to 25 can show this by Ru _x Re _a C _b M 1 _c M 2 _d .

Comparative Examples 1-6: Preparation of conventional pure ruthenium sputtering targets and Ru _x Re _a sputtering targets

  The method of preparing the sputtering target of pure ruthenium of Comparative Example 1 and the sputtering target containing ruthenium / rhenium of Comparative Examples 2 to 6 is as described below.

  Based on the components of the raw material powder shown in Table 1, appropriate amounts of ruthenium powder or ruthenium powder and rhenium powder are weighed and mixed to form a raw material powder. Next, the raw material powder is ground by a high-speed grinder to form a ground powder, the ground powder is uniformly filled in a graphite mold, and a hydraulic device is applied to a pressure of 20 bar to form a green compact. Do. Then, the green compact and the graphite mold are put together in a hot press furnace, and sintering is continued for 3 hours at a sintering temperature of 1000 ° C. to 1300 ° C. and a sintering pressure of 362 bar using a hot press method. A sintered body is formed and processed to obtain a pure ruthenium sputtering target of each comparative example or a sputtering target containing ruthenium / rhenium.

The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Comparative Examples 1 to 6 are as described in Table 1. The sputtering targets containing ruthenium / rhenium of the present comparative examples 2 to 6 can show this by Ru _x Re _a .

Comparative Example 7: Preparation of Ru _x Re _a C _b sputtering target

  The sputtering target containing ruthenium / rhenium of Comparative Example 7 is basically prepared by adopting a hot press method, and the specific method is as described below.

The preparation methods of the sputtering targets containing ruthenium / rhenium of Comparative Example 7 and Examples 1 to 6 are similar. The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Comparative Example 7 are as described in Table 1. The sputtering target containing ruthenium / rhenium of this comparative example 7 can show this by Ru _x Re _a C _b .

Comparative Examples 8 and 9: Preparation of Ru _x Re _a C _b M 1 _c sputtering target

  The sputtering targets containing ruthenium / rhenium of Comparative Examples 8 and 9 are basically prepared by employing the hot isostatic pressing method, and the specific method is as described below.

The preparation methods of the sputtering targets containing ruthenium / rhenium of Comparative Examples 8 and 9 and Examples 7 to 18 are similar. The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Comparative Examples 8 and 9 are as described in Table 1. The sputtering targets containing ruthenium / rhenium of the present comparative examples 8 to 9 can show this by Ru _x Re _a C _b M1 _c .

Comparative Examples 10, 11: Preparation of Ru _x Re _a C _b M 2 _d sputtering target

  The sputtering targets containing ruthenium / rhenium of Comparative Examples 10 and 11 are basically prepared by employing a discharge plasma sintering method, and the specific method is as described below.

The methods of preparing the ruthenium / rhenium containing sputtering targets of Comparative Examples 10 and 11 and Examples 19 to 21 are similar. The constituents of the sputtering target containing ruthenium / rhenium, the sintering method of the green compact and the sintering temperature of the green compact in Comparative Examples 10 and 11 are as described in Table 1. The sputtering target containing ruthenium / rhenium of Comparative Examples 10 and 11 can indicate this by Ru _x Re _a C _b M 2 _d .

  Test Example: Ruthenium crystallinity analysis and grain size analysis in a ruthenium / rhenium containing layer or pure ruthenium layer

The sputtering targets containing ruthenium / rhenium of Examples 1 to 25 and Comparative Examples 2 to 11 and the pure ruthenium sputtering targets of Comparative Example 1 are respectively placed in a magnetron sputtering apparatus (manufacturer: Takahata) and subjected to pre-sputtering first. Remove dirt on the target surface (argon gas flow rate: 30 sccm, vacuum pressure: 3 mtorr, power: 200 W, electric conductivity: 600 S), and perform sputtering respectively to form a ruthenium / rhenium-containing layer or a pure ruthenium layer (Vacuum pressure: 10 ⁻² torr to 10 ⁻³ torr, power: 50 W to 100 W, sputtering time: 15 min to 30 min, thickness of thin film: 50 nm).

Specifically, the Ru _x Re _a C _b sputtering targets of Examples 1 to 6 and Comparative Example 7 can form _a Ru _x Re _a C _b layer according to the above procedure. The Ru _x Re _a C _b M 1 _c sputtering targets of Examples 7 to 18 and Comparative Examples 8 and 9 can form _a Ru _x Re _a C _b M 1 _c layer according to the above procedure. The Ru _x Re _a C _b M 2 _d sputtering targets of Examples 19 to 21 and Comparative Examples 10 and 11 can form _a Ru _x Re _a C _b M 2 _d layer according to the above procedure.
The Ru _x Re _a C _b M 1 _c M 2 _d sputtering target of Examples 22 to 25 can form _a Ru _x Re _a C _b M 1 _c M 2 _d layer according to the above procedure. The pure ruthenium sputtering target of Comparative Example 1 can form a pure ruthenium layer according to the above procedure. _Ru x Re _a sputtering target of Comparative Examples 2 to 6 can form a _Ru x Re _a layer according to the procedure described above.

  After the sputtering process is completed, the ruthenium / rhenium layer or pure ruthenium layer is analyzed by an X-ray diffractometer (X-ray diffractometer, XRD, manufacturer: Rigaku (registered trademark), model number: Ultima IV). And the characteristic peak in the crystal direction of ruthenium (002) and its crystallinity are confirmed.

Take the results of the ruthenium / rhenium containing layers of Examples 1-2 and Comparative Examples 3 and 7 as examples. See Figures 1A and 1B. As the results show, the intensity of the peak value in the direction of ruthenium (002) crystals of Examples 1-2 is slightly higher than the intensity of the peak value in the direction of ruthenium (002) crystals of Comparative Examples 3 and 7. ing.
Furthermore, in order to quantify the intensity ratio in the ruthenium (002) crystal direction, ruthenium (002) in the ruthenium / rhenium containing layers of Examples 1 to 25 and Comparative Examples 2 to 11 and the pure ruthenium layer of Comparative Example 1 The full width at half maximum (FWHM) of the crystal direction strength, that is, the distance between the half points of the peak value in the two function values before and after is calculated. The calculation results are as described in Table 1.

  In addition, a layer or a pure layer containing ruthenium / rhenium of each example and comparative example under a scanning electron microscope (scanning electronic microscopy, SEM, manufacturer: Hitachi (registered trademark), model number: 3400 N, acceleration voltage: 15 kV, working distance: 15 cm) The grain size in the ruthenium layer was analyzed, and the calculation results are as described in Table 1.

  Discussion of experimental results

Based on the results of Table 1 above, the pure ruthenium layer of Comparative Example 1, _Ru x Re _a layer of the comparative examples 2~6, _Ru x _Re a _{C b} layer of Comparative Example 7, _Ru x Re of Comparative Examples 8 and 9 compared to _Ru x _Re a _C b M2 _d layer of _a C _b M1 _c layer and Comparative examples 10 and 11, a layer containing ruthenium / rhenium which is formed from the sputtering target comprising ruthenium / rhenium examples 1 to 25 Have excellent crystallinity (that is, the full width at half maximum of ruthenium (002) crystal lattice direction is all less than 0.38 °) and fine grain size (ie, average grain size is less than 10 nm) Two kinds of characteristics can be obtained simultaneously.
Thus, when the ruthenium / rhenium-containing layer formed from the ruthenium / rhenium-containing sputtering target of Examples 1 to 25 is applied to the intermediate layer of the perpendicular magnetic recording medium, the magnetic crystal grains of the recording layer above the intermediate layer It can be used to improve the crystal orientation structure and the effect of crystal grain refinement, and can further improve the magnetic recording density of the magnetic recording medium.

In addition, comparison and control of experimental results are performed. See the results of Examples 1 to 6 and Comparative Examples 1 to 6. When an appropriate amount of carbon is added to the ruthenium / rhenium-containing layer of Examples 1 to 6, the crystallinity of ruthenium (002) is surely improved and the crystal grains are finely divided. The full width at half maximum (0.24 ° to 0.33 °) of the layer containing ruthenium / rhenium is clearer than the full width at half maximum (0.40 ° to 0.50 °) of the layer containing ruthenium / rhenium of Comparative Examples 1 to 6 The average grain size (6 nm to 9 nm) of the narrow layer containing ruthenium / rhenium of Examples 1 to 6 is also smaller than the average grain size (9 nm to 12 nm) of the ruthenium / rhenium containing layer of Comparative Examples 1 to 6 It is clear that it is small.
In addition, although the layer containing ruthenium / rhenium of Comparative Example 7 adds a carbon component, the content of the carbon component in the layer containing ruthenium / rhenium of Comparative Example 7 reaches 200 ppm, and the upper limit value is 100 ppm. The effect of the crystallinity and grain refinement of ruthenium (002) in the ruthenium / rhenium-containing layer of Comparative Example 7 was also less than expected.

Further investigation of the constituents of the ruthenium / rhenium-containing layer of Examples 7 to 18 shows that suitable amounts of added components such as cobalt, chromium, tungsten, titanium, tantalum, boron or palladium are contained in the ruthenium / rhenium-containing sputtering target. By mixing, crystal nuclei can be formed in the process of sputtering, and the effect of grain refinement can be further enhanced, whereby the full width at half maximum of the ruthenium / rhenium containing layer of Examples 7 to 18 is 0.20 °. It can be seen that the width is narrowed to a range of -0.28 °, and the average grain size is refined to a level of 4 nm to 6 nm. From this, the ruthenium / rhenium-containing layers of Examples 7-18 have better ruthenium (002) crystallinity and finer than the ruthenium / rhenium-containing layers of Examples 1-6. It can be seen that it can have different grain sizes.
Besides, from the experimental results of Comparative Examples 8 and 9, although the above-mentioned additive components are mixed also in the ruthenium / rhenium-containing layers of Comparative Examples 8 and 9, because the contents of the additive components are not controlled at the same time. The full width at half maximum (0.38 ° to 0.39 °) of the ruthenium / rhenium containing layer of Comparative Examples 8 and 9 is the full width at half maximum (0.20 ° to 0.20 ° to 20) of the ruthenium / rhenium containing layer of Examples 7-18. The average crystal grain size (8 nm to 9 nm) of the ruthenium / rhenium containing layer of Comparative Examples 8 and 9 is clearly wider than the 0.28 °) and the average crystal of the ruthenium / rhenium containing layer of Examples 7 to 18 It can be seen that it is larger than the grain size (4 nm to 6 nm).

In analogy, further investigation of the constituents of the ruthenium / rhenium containing layers of Examples 19 to 21 shows that appropriate amounts of silicon dioxide, titanium dioxide, chromium trioxide, trioxide dioxide in the layer containing ruthenium / rhenium are included. When an oxide such as boron or tantalum pentoxide is mixed, it segregates around ruthenium / rhenium, and this helps to refine the crystal grains, thereby achieving the half value of the ruthenium / rhenium containing layer of Examples 19 to 21. It can be seen that the overall width can be narrowed to a range of 0.23 ° to 0.26 ° and the average grain size can be refined to a level of 4 nm to 5 nm.
From this, the ruthenium / rhenium-containing layers of Examples 19 to 21 have better ruthenium (002) crystallinity and finer than the ruthenium / rhenium-containing layers of Examples 1-6. It can be seen that it can have different grain sizes. Besides, from the experimental results of Comparative Examples 10 and 11, although the oxides are mixed also in the ruthenium / rhenium-containing layer of Comparative Examples 10 and 11, the content of the oxide is 0 wt% to 40 at the same time. Since the control is not controlled to be between the weight percentages, the full width at half maximum (0.41 ° to 0.42 °) of the ruthenium / rhenium containing layer of Comparative Examples 10 and 11 is the ruthenium / Examples of Examples 19 to 21. It can be seen that it is clearly wider than the full width at half maximum (0.23 ° to 0.26 °) of the layer containing rhenium.

  Further detailed investigation of the components of Examples 22 to 25 shows that, in the layer containing ruthenium / rhenium, appropriate amounts of cobalt, chromium, tungsten, titanium, tantalum, boron or palladium, and additional components such as silicon dioxide, titanium dioxide, trioxide trioxide. By mixing an oxide such as chromium, diboron trioxide or tantalum pentoxide, crystal nuclei can be formed in the process of sputtering, and the effect of grain refinement can be further enhanced. It can be seen that the full width at half maximum of H is further narrowed to the range of 0.19 ° or less, and the average grain size is further refined to the level of 4 nm or less. From this, the ruthenium / rhenium-containing layer of Examples 22-25 is superior to the ruthenium / rhenium-containing layer of Examples 1-6, 7-18, or 19-21. It can be seen that it can have the crystallinity of ruthenium (002) and a finer grain size.

  In summary, the present invention controls the component ratio of the sputtering target containing ruthenium / rhenium and the layer containing ruthenium / rhenium to surely improve the crystallinity of ruthenium (002) and refine the crystal grains, Thus, when the intermediate layer of the perpendicular magnetic recording medium is used, the crystallinity of the recording layer can be assisted, and by making the recording layer have fine crystal grains, the effect of increasing the magnetic recording density can be achieved.

Claims (17)

A sputtering target comprising ruthenium / rhenium,
Contains ruthenium, rhenium and carbon,
The content of the rhenium is 0.1% by weight to 45% by weight, and the content of the carbon is 0.003% by weight to 0.01% by weight, based on the total weight of the entire sputtering target including ruthenium / rhenium The component of is ruthenium
A sputtering target containing ruthenium / rhenium.   An additive component, wherein the additive component is selected from the group consisting of cobalt, chromium, tungsten, titanium, tantalum, boron, palladium and compositions thereof, based on the total weight of the entire sputtering target including ruthenium / rhenium, The ruthenium / rhenium-containing sputtering target according to claim 1, wherein the content of the additive component is greater than 0 weight percent and up to 60 weight percent.   The ruthenium / rhenium-containing sputtering target according to claim 2, wherein the content of the additive component is 10 wt% to 40 wt%, based on the total weight of the entire sputtering target containing ruthenium / rhenium.   The ruthenium / rhenium-containing sputtering target according to claim 3, wherein a content of the added component is 20 weight percent to 30 weight percent based on a total weight of the entire sputtering target containing ruthenium / rhenium.   The oxide is comprised of silicon dioxide, titanium dioxide, chromium trioxide, diboron trioxide, tantalum pentoxide pentoxide, cobalt monoxide, cobalt trioxide, tungsten trioxide and compositions thereof 5. The oxide as claimed in claim 1, wherein the content of the oxide is greater than 0% by weight and up to 40% by weight, based on the total weight of the entire sputtering target selected from the group comprising ruthenium / rhenium. The sputtering target containing ruthenium / rhenium as described in.   The sputtering target containing ruthenium / rhenium according to claim 5, wherein the content of the oxide is 5 wt% to 35 wt%. A method of making a sputtering target comprising ruthenium / rhenium, comprising
The raw material powder is all prepared, the raw material powder contains ruthenium, rhenium and carbon, and the content of the rhenium is 0.1% by weight to 45% by weight, based on the total weight of the whole raw material powder. Containing 0.003% by weight to 0.01% by weight and the remaining component being ruthenium,
Sintering the raw material powder at a temperature of 800 ° C. to 1300 ° C. to obtain a sputtering target containing the ruthenium / rhenium.
Method of making a sputtering target containing ruthenium / rhenium.   The method according to claim 7, wherein the raw material powder is an elemental powder, a prealloyed powder, or a mixture thereof.   The raw material powder contains an additive component, and the additive component is selected from the group consisting of cobalt, chromium, tungsten, titanium, tantalum, boron, palladium and the composition thereof, and the total weight of the entire sputtering target including ruthenium / rhenium The method according to claim 7, wherein the content of the additive component is greater than 0% by weight and up to 60% by weight on the basis of   The raw material powder contains an oxide, which is silicon dioxide, titanium dioxide, dichromium trioxide, diboron trioxide, ditantalum pentaoxide, cobalt monoxide, dicobalt trioxide, tungsten trioxide and compositions thereof The oxide according to claim 7, wherein the content of the oxide is greater than 0% by weight and up to 40% by weight based on the total weight of the entire sputtering target including ruthenium / rhenium selected from the group consisting of Manufacturing method.   The method according to claim 7, wherein the procedure of preparing all the raw material powder includes the steps of polishing the raw material powder, forming a powder after polishing, and performing a sintering reaction on the powder after polishing. .   Sintering is performed at a temperature of 1000 ° C. to 1300 ° C. and a pressure of 200 bar to 600 bar using a hot press method in the procedure for obtaining the sputtering target containing the ruthenium / rhenium by sintering, and containing the ruthenium / rhenium The method according to any one of claims 7 to 11, comprising the procedure of forming a sputtering target.   Sintering is performed at a temperature of 1000 ° C. to 1300 ° C. and a pressure of 1000 bar to 2000 bar using a hot isostatic pressing method in the procedure for obtaining a sputtering target containing the ruthenium / rhenium by sintering. The method according to any one of claims 7 to 11, comprising the steps of: forming a sputtering target comprising:   Sintering is performed at a temperature of 800 ° C. to 1200 ° C. and a pressure of 300 bar to 1000 bar using a discharge plasma sintering method in the procedure for obtaining the sputtering target containing the ruthenium / rhenium by sintering, and the ruthenium / rhenium mentioned above The method according to any one of claims 7 to 11, comprising forming a sputtering target comprising A layer containing ruthenium / rhenium,
Contains ruthenium, rhenium and carbon,
The content of the rhenium is 0.1% by weight to 45% by weight, the content of the carbon is 0.003% by weight to 0.01% by weight, based on the total weight of the layer containing ruthenium / rhenium, and the remaining components. Is ruthenium, and the ruthenium / rhenium-containing layer contains ruthenium / rhenium having an average grain size smaller than 10 nanometers,
layer.   The ruthenium / rhenium containing layer according to claim 15, wherein the full width at half maximum of the ruthenium / rhenium containing layer is less than 0.37 °.   A layer comprising ruthenium / rhenium according to claim 15, produced from a sputtering target comprising ruthenium / rhenium according to any one of claims 1-6.

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