TWI659119B - Nickel-rhenium alloy sputtering target and method of preparing the same - Google Patents

Abstract

This creation provides a nickel-rhenium alloy target and its manufacturing method. The nickel-rhenium alloy target includes nickel, hafnium, and a first metal component. The first metal component includes aluminum, zirconium, or a combination thereof. Based on the total number of atoms of the nickel-rhenium alloy target, the content of hafnium is greater than 0 atomic percent and less than Or equal to 7 atomic percent, the total content of the first metal component is greater than 0 atomic percent and less than or equal to 3 atomic percent, and the total content of rhenium and the first metal component is greater than 0 atomic percent and less than 10 atomic percent. By controlling the composition of the nickel-rhenium alloy target, the original nickel-rhenium alloy target can be applied to sputtering to form a seed layer of a perpendicular magnetic recording medium, thereby improving its recording density.

Description

Nickel-rhenium alloy target and preparation method thereof

This creation relates to a target of a magnetic recording medium and a manufacturing method thereof, and more particularly to a nickel-rhenium alloy target applicable to a seed layer of a perpendicular magnetic recording medium and a manufacturing method thereof.

With the increasing demand for information storage capacity of magnetic recording media, how to improve the recording quality of magnetic recording media has been a research topic actively developed by industry players. According to the magnetization direction of the magnetic head, the magnetic recording media of the prior art can be divided into horizontal magnetic recording media and vertical magnetic recording media. Among them, the recording density of the horizontal magnetic recording medium has developed to the limit; therefore, the existing technology has turned to the research of the vertical magnetic recording medium, trying to improve the magnetic recording medium by refining the recording unit and stacking the vertical layered structure. Its recording density.

The layered structure of a normal perpendicular magnetic recording medium includes a substrate, an adhesion layer, a soft underlayer, a seed layer, an intermediate layer, a magnetic recording layer, Covering layer and lubricating layer.

In order to ensure that the seed layer obtains a crystalline structure of a face-centered cubic (FCC), in the prior art, nickel-tungsten alloy, nickel-iron-tungsten alloy, or nickel-rhenium alloy is mostly used as the main component of the seed layer. However, the seed layer of the prior art mostly has coarse grains (that is, the average grain size is 100 μm to 150 μm), and the particle size varies greatly (that is, the uniformity of the average grain size is about 25% to 40%) and insufficient crystallinity (that is, the intensity ratio of the (111) crystal direction in the FCC structure is less than 60%), causing the magnetic recording layer deposited on the seed layer to be affected, and crystals also exist. Coarse grain Defects such as large particle size variation and poor crystallinity even reduce the recording density of magnetic recording media.

In view of this, it is still necessary to try to refine and uniformize the grain size of the seed layer, and at the same time, try to improve the crystallinity of the seed layer, thereby improving the quality of the magnetic recording layer formed on the seed layer. , Thereby achieving the purpose of improving the recording density of the magnetic recording medium.

In view of the shortcomings of the prior art, one purpose of this creation is to refine and homogenize the grain size of the nickel-rhenium alloy target, so as to make the seed layer formed by sputtering of the nickel-rhenium alloy target more effective. Effect of refinement and homogenization of grain size. Accordingly, when such a seed layer is applied to a magnetic recording medium, it can help to refine and uniformize the grain size of the magnetic recording layer deposited on the seed layer, and even improve the recording density of the magnetic recording medium.

Another purpose of this creation is to improve the crystallinity of the nickel-rhenium alloy target, so that the seed layer formed by sputtering the nickel-rhenium alloy target can also have better crystallinity; therefore, when the seed layer is applied to magnetic When recording a medium, it can help improve the crystallinity of the magnetic recording layer deposited on the seed layer, thereby improving the recording density of the magnetic recording medium.

In order to achieve the foregoing object, the present invention provides a nickel-rhenium alloy target, which includes nickel, rhenium, and a first metal component. The first metal component includes aluminum, zirconium, or a combination thereof, based on the total number of atoms of the nickel-rhenium alloy target. , The content of rhenium is greater than 0 atomic percent (at%) and less than or equal to 7at%, the total content of the first metal component is greater than 0at% and less than or equal to 3at%, the rest is nickel, and the total content of rhenium and the first metal component More than 0at% and less than 10at%.

According to this creation, by including an appropriate amount of rhenium in the nickel-rhenium alloy target material as a refining metal, it can help refine and uniformize the grain size of the nickel-rhenium alloy target material, ensuring the nickel-rhenium alloy target. The average grain size of the material is less than or equal to 30 microns, and the uniformity of the average grain size is less than or equal to 20%. Based on this, compared with the nickel-based target material of the prior art, this creation can specifically solve the nickel-based target There are some problems such as coarse grains and large variation in grain size. At the same time, by including a specific kind of first metal component and a proper amount of the first metal component in the nickel-rhenium alloy target, in addition to the effect of maintaining the fineness and uniformity of the grain size of the nickel-rhenium alloy target In addition, the crystallinity of the nickel-rhenium alloy target can be improved at the same time, so that the strength ratio of the (111) crystal direction in the face-centered cubic structure (FCC structure) of the nickel-rhenium alloy target exceeds 62%.

According to this, the nickel-rhenium alloy target material created by this invention can be applied to form a seed layer for magnetic recording media by sputtering, so that the seed layer can obtain a relatively fine and uniform grain size, and at the same time has a better The crystallinity causes the magnetic recording layer deposited on the seed layer to obtain a more refined and uniform grain size and better crystallinity, thereby improving the recording density of the magnetic recording medium.

According to this creation, the first metal component in the nickel-rhenium alloy target may be composed of aluminum, zirconium, or a combination of aluminum and zirconium. When the first metal component is composed of a single metal component, the total content of the first metal component is equal to the individual content of the single metal component. At this time, the individual content of the first metal component is greater than 0at% and less than or equal to 3at%. And the total content of rhenium and the first metal component is greater than 0 at% and less than 10 at%. When the first metal component is a combination of aluminum and zirconium, the sum of the individual content of aluminum and the individual content of zirconium is equivalent to the total content of the first metal component. At this time, the total content of the first metal component is greater than 0 at% And less than or equal to 3 at%, and the total content of rhenium and the first metal component is greater than 0 at% and less than 10 at%.

Preferably, when the first metal component in the nickel-rhenium alloy target is aluminum, the total content of the first metal component (ie, the individual content of aluminum) is greater than or equal to 0.5 at% and less than or equal to 2 at%; when nickel When the first metal component in the samarium alloy target is zirconium, the total content of the first metal component (ie, the individual zirconium content) is greater than or equal to 0.5 at% and less than or equal to 2.8 at%; When the first metal component is a combination of aluminum and zirconium, the total content of the first metal component (ie, the sum of the contents of aluminum and zirconium) is greater than or equal to 0.5 at% and less than or equal to 3 at%.

Preferably, based on the total number of atoms of the nickel-rhenium alloy target, the total content of the first metal component in the nickel-rhenium alloy target is greater than 0 at% and less than or equal to 2.9 at%. More preferably, based on the total number of atoms of the nickel-rhenium alloy target, the total content of the first metal component in the nickel-rhenium alloy target is greater than or equal to 0.5 at% and less than or equal to 2.5 at%.

According to this creation, in addition to the nickel-rhenium alloy target material containing the aforementioned nickel, rhenium, and a specific kind of first metal component, an appropriate amount of a second metal component can be optionally added to further refine the nickel-rhenium alloy target material. Crystal grain size and strength ratio of (111) crystal direction.

Preferably, based on the total number of atoms of the nickel-rhenium alloy target, the total content of rhenium and the first metal component is greater than or equal to 2 at% and less than or equal to 9 at%; more preferably, the nickel-rhenium alloy target is used. Based on the total number of atoms, the total content of rhenium and the first metal component is 4at% or more and 9at% or less.

Preferably, the second metal component includes titanium, osmium, iridium, yttrium, tantalum, niobium, molybdenum, or a combination thereof; more preferably, the second metal component may be titanium, niobium, molybdenum, or a combination thereof.

Preferably, based on the total number of atoms of the nickel-rhenium alloy target, the total content of the second metal component is greater than or equal to 0 at% and less than or equal to 5 at%, and the total of thorium, the first metal component, and the second metal component The content is greater than 0at% and less than 10at%. By controlling the content of the second metal component, the crystallinity of the nickel-rhenium alloy target can be further improved on the premise of ensuring the refinement and uniformity of the grain size.

Preferably, based on the total number of atoms of the nickel-rhenium alloy target, the total content of rhenium, the first metal component, and the second metal component is greater than or equal to 0.5 at% and less than or equal to 9.9 at%; more preferably, The total number of atoms of the nickel-rhenium alloy target is based on the total content of rhenium, the first metal component and the second metal component being greater than or equal to 5 at% and less than or equal to 9.9 at%.

Preferably, when the second metal component in the nickel-rhenium alloy target is titanium, the total content of the second metal component (that is, the individual content of titanium) is greater than or equal to 0.5 at% and less than or equal to 3 at%; when nickel When the second metal component in the samarium alloy target is niobium, the total content of the second metal component (ie, the individual content of niobium) is greater than or equal to 0.5 at% and less than or equal to 3 at%; When the second metal component is molybdenum, the total content of the second metal component (ie, the individual content of molybdenum) is greater than or equal to 0.5 at% and less than or equal to 3 at%.

Preferably, the nickel-rhenium alloy target may be further blended with iron, and based on the total number of atoms of the nickel-rhenium alloy target, the iron content may be greater than 0 at% and less than or equal to 30 at%. Preferably, the content of iron may be greater than or equal to 15 at% and less than or equal to 25 at%. By controlling the content of iron, the crystallinity of the nickel-rhenium alloy target can be further improved under the premise of ensuring the refinement and uniformity of the grain size of the nickel-rhenium alloy target, and avoiding the deterioration of the crystal of the nickel-rhenium alloy target by adding excessive iron. Sex.

Preferably, the crystal structure of the nickel-rhenium alloy target material contains an FCC phase, so it can be beneficial to sputtering to form a seed layer applied to a vertical recording medium. More preferably, the crystal structure of the nickel-rhenium alloy target is composed of an FCC phase.

In order to achieve the aforesaid objective, the present invention also provides a method for manufacturing a nickel-rhenium alloy target material, which includes: smelting a vacuum induction melting method under a vacuum environment of 1 × 10 ^-2 Torr to 1 × 10 ^-4 Torr A metal raw material is cast at a temperature of 1500 ° C to 1750 ° C to obtain a pre-alloy ingot; the pre-alloy ingot is atomized to obtain a pre-alloy powder; and the sintering temperature is sintered at a sintering temperature of 1000 to 1300 ° C. Pre-alloyed powder to obtain the nickel-rhenium alloy target.

Here, the composition of the metal raw material may be the same as that of the above-mentioned nickel-rhenium alloy target material, so as to ensure that the nickel-rhenium alloy target material with a specific composition can be obtained after the metal raw material passes the production method of the present invention. Specifically, the metal raw material may contain nickel, hafnium, and a first metal component. The first metal component includes aluminum, zirconium, or a combination thereof. Based on the total number of atoms of the metal raw material, the content of hafnium is greater than 0 at% and less than or equal to 7at%, the total content of the first metal component is greater than 0at% and less than or equal to 3at%, and the total content of the first metal component is greater than 0at% and less than 10at%.

According to the above composition of the nickel-rhenium alloy target, the metal raw material may further contain a second metal component, and the second metal component includes titanium, osmium, iridium, yttrium, tantalum, niobium, molybdenum, or a combination thereof. Based on the total number of atoms, the total content of the second metal component is greater than 0 at% and less than or equal to 5 at%, and the total content of thorium, the first metal component, and the second metal component is greater than 0 at% and less than 10 at%.

Like the above-mentioned nickel-rhenium alloy target material, the metal raw material may further contain iron. Based on the total number of atoms of the metal raw material, the iron content is greater than or equal to 0 at% and less than or equal to 30 at%.

Preferably, the manufacturing method is in a vacuum environment of 1 × 10 ^-2 Torr to 1 × 10 ^-4 Torr, and the temperature is first maintained at a temperature higher than the pouring temperature of 100 ° C, and then the temperature is maintained at 1500 ° C to 1750 ° C. The pre-alloyed ingot is obtained by casting at a temperature.

Preferably, the atomizing step may be performed in a vacuum environment of 1 × 10 ^-2 Torr to 1 × 10 ^-5 Torr, and an atomizing temperature of 1500 ° C to 1750 ° C and an atomizing temperature of 7MPa to 9MPa. The atomization step is performed under pressure to obtain a pre-alloyed powder.

Here, the pre-alloy powder may be a single pre-alloy powder or at least two different pre-alloy powders. In other words, in one embodiment, the aforementioned sintering step is sintering a single prealloy powder separately to obtain the nickel-rhenium alloy target; or, in another embodiment, the aforementioned sintering step is sintering at least two different types simultaneously Pre-alloyed powder to obtain the nickel-rhenium alloy target.

Preferably, the sintering step may be completed by a hot press method (HP), a hot isostatic pressing method (HIP), or a combination thereof, but is not limited thereto. More preferably, the production method of the present invention can first use the hot pressing method and then the hot equalizing method to sinter the prealloy powder to obtain the nickel-rhenium alloy target.

In the aforementioned sintering step, when the pre-alloy powder is sintered by the hot pressing method, the sintering temperature is preferably 1000 ° C. to 1300 ° C., and the sintering pressure is preferably 300 bar to 400 bar.

In the aforementioned sintering step, when the pre-alloy ingot or pre-alloy powder is sintered by the hot equalizing method, the sintering temperature is preferably 1000 ° C. to 1300 ° C., and the sintering pressure is preferably 130 MPa to 200 MPa.

1A to FIG. 1C are optical microscope image diagrams of the nickel-rhenium alloy targets of Examples 6, 8, and 9, in order.

2A and 2B are optical microscope image diagrams of the nickel-tungsten alloy target of Comparative Example 1 and the nickel-rhenium alloy target of Comparative Example 6, respectively.

3 is an X-ray diffraction pattern of the nickel-rhenium alloy target of Examples 6, 8, and 9, the nickel-tungsten alloy target of Comparative Example 1, and the nickel-rhenium alloy targets of Comparative Examples 6 and 8.

In order to verify the effect of the composition of the nickel-rhenium alloy target on its grain size, uniformity, and crystallinity, several nickel-rhenium alloy targets with different compositions are listed below as examples to explain the implementation of this creation. In combination with other nickel-based alloy targets as comparative examples, the differences in characteristics between the examples and comparative examples will be explained; those skilled in the art can easily understand the advantages and effects that can be achieved by this creation through the content of this manual, and will not deviate from it. Various modifications and changes are made in the spirit of this creation to implement or apply the content of this creation.

Examples 1 to 19: nickel-rhenium alloy targets

According to the composition of the nickel-rhenium alloy target shown in Table 1 below, weigh and mix an appropriate amount of nickel (Ni), rhenium (Re), iron (Fe), the first metal component (M1), and the second metal component (M2). ) And other raw materials, using a vacuum induction melting method, in a vacuum environment of 5 × 10 ^-2 Torr, and a reaction temperature higher than the pouring temperature of 100 ° C, the temperature is maintained, and the casting temperature of 1650 ° C to 1670 ° C to obtain a pre-alloy casting ingot. Here, the first metal component may be aluminum (Al), zirconium (Zr), or a combination thereof, and the second metal component includes titanium (Ti), hafnium (Os), iridium (Ir), yttrium (Y), tantalum (Ta ), Niobium (Nb), molybdenum (Mo), or a combination thereof.

After that, the pre-alloy was cast under a vacuum environment of 1 × 10 ^-2 Torr to 1 × 10 ^-5 Torr, an atomization temperature of 1680 ° C. to 1740 ° C., and an atomization pressure of 8 MPa using an atomizing and granulating equipment. The ingot is atomized into a pre-alloyed powder.

Next, the pre-alloy powder is sieved, and then hot-pressed and sintered at a temperature of 1200 ° C and a pressure of 350 bar for 2 hours to obtain a sintered body.

Finally, the sintered body was continuously hot-pressed at a temperature of 1100 ° C and a pressure of 175 MPa for 1 hour; subsequently, it was processed by wire cutting and computer numerical control (CNC) lathe to obtain the examples and comparative examples. Pie-shaped nickel-rhenium alloy target (pie-shaped target with a diameter of 165 mm and a thickness of 4 mm).

As shown in Table 1 below, the composition of the nickel-rhenium alloy targets of the examples and comparative examples can be represented by the general formula such as Ni-aRe-b1Al-b2Zr-c1Ti-c2Nb-c3Mo-c4Ta-c5Os-c6Ir-c7Y-dFe ; A represents the content ratio of thorium relative to the total number of atoms of the nickel-rhenium alloy target, b1 and b2 sequentially represent the content ratio of aluminum and zirconium relative to the total number of atoms of the nickel-rhenium alloy target, c1, c2, c3, c4, c5 , C6, c7 sequentially represent the content ratio of titanium, niobium, molybdenum, tantalum, osmium, iridium, yttrium relative to the total number of atoms of the nickel-rhenium alloy target, and d represents the content ratio of iron relative to the total number of atoms of the nickel-rhenium alloy target , Its unit is atomic percentage (at%). The sum of b1 and b2 represents the total content of the first metal component, and the sum of c1 to c7 represents the total content of the second metal component.

In this specification, the "total content of the first metal component" refers to the total of b1 and b2, and the "total content of rhenium and the first metal component" refers to the total of a, b1, and b2; The "total content of the second metal component" refers to the total of c1, c2, c3, c4, c5, c6, and c7, and the "total content of thorium, the first metal component, and the second metal component" means a , B1, b2, c1, c2, c3, c4, c5, c6, and c7.

Comparative Example 1: Nickel-Tungsten Alloy Target

In this comparative example, nickel and tungsten are used as raw materials, and the nickel-tungsten alloy target material of Comparative Example 1 is obtained after vacuum induction melting, atomization, sintering, and subsequent lathe processing steps according to the manufacturing method described in the previous embodiment. The composition of the nickel-tungsten alloy target of Comparative Example 1 can be shown by Ni-5W, wherein the content of tungsten relative to the total number of atoms of the nickel-tungsten alloy target is 5 at%, and the rest is nickel. That is, the nickel-tungsten alloy target of the comparative example does not contain any rhenium and the first metal component; further, the nickel-tungsten alloy target of the comparative example does not include the second metal component.

Comparative Example 2: Nickel-rhenium alloy target

This comparative example uses nickel and rhenium as raw materials, and according to the manufacturing method described in the previous embodiment, after sequentially undergoing the steps of vacuum induction melting, atomization, sintering, and back-end lathe processing, the nickel-rhenium alloy target of Comparative Example 2 is obtained. The composition of the nickel-rhenium alloy target of Comparative Example 2 can be shown by Ni-5Re, in which the content of rhenium with respect to the total number of atoms of the nickel-rhenium alloy target is 5 at%, and the rest is nickel. From the composition of the nickel-rhenium alloy target of Comparative Example 2, it can be seen that the nickel-rhenium alloy target of this comparative example does not contain any first metal component; further, the nickel-tungsten alloy target of this comparative example does not contain The second metal component.

Comparative examples 3 and 4: nickel-iron alloy targets

This comparative example mainly uses nickel and iron as the main raw materials. In addition, other metal components shown in Table 1 are added. After the vacuum induction melting, sintering, and back-end lathe processing steps are sequentially performed according to the manufacturing method described in the previous embodiment, they are obtained separately. Nickel-iron alloy targets of Comparative Examples 3 and 4. The composition of the nickel-iron alloy target of Comparative Example 3 can be shown by Ni-1Al-25Fe, wherein the content of aluminum relative to the total number of atoms of the nickel-iron alloy target is 1 at%, and the content of iron relative to the total number of atoms of the nickel-iron alloy target 25at%, the rest is nickel. The composition of the nickel-iron alloy target of Comparative Example 4 can be shown by Ni-2Al-2Zr-1Ti-25Fe, wherein the content of aluminum relative to the total number of atoms of the nickel-iron alloy target is 2at%, and the total number of atoms of zirconium relative to the nickel-iron alloy target The content of iron is 2at%, the content of titanium relative to the total number of atoms of the nickel-iron alloy target is 1at%, the content of iron relative to the total number of atoms of the nickel-iron alloy target is 25at%, and the rest is nickel.

It can be seen from the composition of Table 1 below that none of the nickel-iron alloy targets of Comparative Examples 3 and 4 contains hafnium metal; although the nickel-iron alloy targets of Comparative Example 4 contain aluminum and zirconium as the first metal component and titanium as the second metal component, However, the total content of its first metal component has exceeded 3at%. Furthermore, the nickel-iron alloy target of Comparative Example 3 does not contain any second metal component.

Comparative examples 5 to 9: nickel-rhenium alloy target

The nickel-rhenium alloy targets of Comparative Examples 5 to 9 mainly use nickel and rhenium, in addition to other metal components shown in Table 1 below, and are sequentially subjected to vacuum induction melting, atomization, sintering, and After the subsequent lathe processing steps, the nickel-rhenium alloy targets of Comparative Examples 5 to 9 were obtained.

As can be seen from the composition of Table 1 below, the content of rhenium in the nickel-rhenium alloy target of Comparative Example 5 has exceeded 7at%; the nickel-rhenium alloy targets of Comparative Examples 6 and 7 do not contain any first metal component; The nickel-rhenium alloy target does not contain a second metal component, and the total content of the first metal component has exceeded 3at%, and the total content of the rhenium and the first metal component has reached 10at%; the nickel-rhenium alloy target of Comparative Example 9 Although titanium is contained as the second metal component, the total content of the first metal component in the nickel-rhenium alloy target of Comparative Example 9 has exceeded 3 at%, and the total content of the hafnium and the first metal component has exceeded 10 at%.

Furthermore, the total content of the second metal component in the nickel-rhenium alloy target of Comparative Example 7 has exceeded 5 at%, so that the total content of the europium and the second metal component has also exceeded 10 at%; the nickel-rhenium alloy of Comparative Example 9 The total content of tritium, the first metal component and the second metal component in the target has exceeded 10 at%.

Test example 1: target microstructure

This test example uses an optical microscope to observe the microstructure of the targets in the above examples and comparative examples to confirm whether the composition of the nickel-rhenium alloy target can be controlled to achieve the effects of refinement and uniform grain size.

Exemplary illustrations are made using optical microscope image diagrams of the nickel-rhenium alloy targets of Examples 6, 8 and 9, the nickel-tungsten alloy targets of Comparative Example 1, and the nickel-rhenium alloy targets of Comparative Examples 6 and 8; from FIG. 1A From the comparison results of FIG. 1C and FIG. 2A and FIG. 2B, it can be known that controlling the composition of the nickel-rhenium alloy target material can help to refine and homogenize the grain size of the nickel-rhenium alloy target materials of Examples 6, 8, and 9, In contrast, the composition of the nickel-tungsten alloy target of Comparative Example 1 does not contain an appropriate amount of rhenium and the first metal component, which causes the problem of coarse grains in the nickel-tungsten alloy target of Comparative Example 1 to be apparent. Since the nickel-rhenium alloy target of 6 does not contain any first metal component, the nickel-rhenium alloy target of Comparative Example 6 has a problem that the grain size is relatively uneven.

According to the results of this test example, by appropriately controlling the composition and manufacturing method of the nickel-rhenium alloy target, the grain size of the nickel-rhenium alloy layer sputtered by using this nickel-rhenium alloy target is relatively fine, and The uniformity of the grain size is also better, so it can solve the problems of conventional nickel-based alloy targets that have coarse grains and large variations in grain size.

Test Example 2: Average grain size and uniformity of grain size

In order to verify again that the technical means of this creation can simultaneously refine and homogenize the grain size of nickel-rhenium alloy target materials, this test example uses the target materials of the above examples and comparative examples as the test samples, and The test samples are analyzed according to the same method as described below: by wire cutting, take a size of about 10 mm × 10 at the center of each target, half the radius (r / 2) and edge (r) of the target Test pieces in millimeters. Next, the top surface of the target is etched with a mixed etching solution of pure water, hydrochloric acid, nitric acid, and hydrogen peroxide; at a magnification of 500 times, use an optical microscope to take 5 different positions on each test strip (including the center of the test strip and the (Upper, lower, left, and right of the center) The microstructure of each target material is obtained by 15 optical microscope image images, and the observation areas of the 15 optical microscope image images are staggered from each other.

Next, draw four cut lines on each optical microscope image, two of which are diagonal lines of the image, and the other two cut lines are respectively the center line parallel to the long side and the center line parallel to the short side. The cut lines are arranged in a m-shape on each image.

Subsequently, the total number of grains on the four cut lines is counted by this sampling. If one grain has been calculated on one end of the cut line, the other end of the cut line is not included in the calculation even if one grain passes through. After counting the total number of grains on each section, the actual length of each section on the target (that is, the length of the section on the optical microscope image multiplied by the scale) is divided by the total number of grains to obtain the grains on each section.径 Dimensions.

Then, the data of the crystal grain size on each section line (a total of 60 sets of data for each sample to be tested) are calculated according to the foregoing calculation, and the average crystal grain size and the standard deviation of all the sections are calculated.

Here, the average grain size of each sample to be measured is obtained by the following calculation method. First, the four groups of grain size data intercepted from the first observation area of the central test piece of each test sample are averaged to obtain d ₁ ; then the second of the central test piece of each test sample is obtained. The data of the four groups of grain size data intercepted in the observation area are averaged to obtain d ₂ ; and so on, the d ₃ , d ₄ and d _{5 are} obtained by analogy on the central test piece. Next, the data of the 4 groups of grain size of the sample to be measured in the first observation area of the test piece with a half radius of the target are averaged to obtain d ₆ ; The data of the four groups of grain size measured by the sample in the second observation area of the test piece with a half radius of the target are averaged to obtain d ₇ ; and so on at half of the target A radius test piece obtained d ₈ , d ₉ and d ₁₀ . In the same way, the data of the four groups of grain size sizes intercepted by the first observation area of the edge test piece of each test sample are averaged to obtain d ₁₁ ; and then the first The data of the four groups of grain size data intercepted in the two observation areas were averaged to obtain d ₁₂ ; and so on were obtained on the central test piece to obtain d ₁₃ , d ₁₄ and d ₁₅ . The above d ₁ to d _{15 are} averaged to obtain the average grain size of each sample to be measured.

The percentage calculated by dividing the standard deviation by the average grain size represents the normalized uniformity of grain size. The larger the percentage of the uniformity of the grain size, the more serious the degree of variation, that is, the more uneven the grain size of the sample to be tested. The analysis results of the average grain size and the uniformity of the grain size of the targets of the respective examples and comparative examples are listed in Table 1 above.

Test example 3: (111) ratio of intensity in the crystal direction

This test example uses the nickel-rhenium alloy targets of Examples 1 to 19, the nickel-tungsten alloy targets of Comparative Example 1, the nickel-iron alloy targets of Comparative Examples 3 and 4, and the nickel-rhenium alloy targets of Comparative Examples 2 and 5 to 9. For the samples to be tested, the X-ray diffractometer (XRD) was used to analyze the crystal form of each sample to be tested and its (111) crystal direction intensity.

In this test example, each sample to be tested is sequentially ground with sandpaper numbers # 60, # 120, # 240, # 320, # 600, # 1000, # 1500, # 2000, and # 4000, and polished with alumina. The liquid is polished to a mirror surface, and then placed in an XRD machine, and measured at a step angle of 0.04 ° in a scanning range of 20 ° to 80 °.

Taking the nickel-rhenium alloy targets of Examples 6, 8, and 9, the nickel-tungsten alloy targets of Comparative Example 1, and the nickel-rhenium alloy targets of Comparative Examples 6 and 8 as examples, the XRD spectra are shown in FIG. 3. In FIG. 3, 2θ falls at 44.58 °, 51.89 °, and 76.61 ° are characteristic peaks of the (111) crystal direction, (200) crystal direction, and (220) crystal direction in the FCC crystal structure, respectively.

It can be seen from FIG. 3 that the characteristic peaks in the (111) crystal direction in the XRD spectra of the nickel-tungsten alloy targets of Comparative Example 1 and the nickel-rhenium alloy targets of Comparative Examples 6 and 8 are compared with the characteristic peaks of (111) crystal directions in Examples 6, 8, and 9. The characteristic peak intensity of the (111) crystal direction in the XRD spectrum of the nickel-rhenium alloy target is obvious. In addition, in the XRD spectrum of the nickel-rhenium alloy target of Comparative Example 8, the formation of ZrO ₂ precipitated phase, ZrO precipitated phase, and Al ₂ O ₃ precipitated phase can be further observed, as indicated by arrows in FIG. 3.

In order to further quantify the intensity ratio of the (111) crystal direction, the characteristics of the (111) crystal direction, (200) crystal direction, and (220) crystal direction in the XRD spectrum measured in each of the examples and comparative examples are also included in this test example. The peak intensity was converted by the calculation formula shown below to obtain the intensity ratio in the (111) crystal direction. The results are shown in Table 1 above.

According to the above calculation formula, the intensity ratio in the (111) crystal direction can be obtained. The larger the intensity ratio in the (111) crystal direction is, the better the crystallinity of the target material is. The nickel-rhenium alloy target material with better crystallinity is sputtered to form the vertical magnetism. The seed layer of the recording medium can ensure the crystal structure of the magnetic recording layer formed on the seed layer, thereby improving the recording density of the perpendicular magnetic recording medium.

Discussion of experimental results

Looking at the results of the above test examples 1 to 3, it can be seen that the composition of the nickel-rhenium alloy targets of Examples 1 to 19 contains nickel, rhenium, and a specific kind of first metal component. The content of rhenium is greater than 0at% and less than or equal to 7at. %, The total content of the first metal component is greater than or equal to 0at% and less than or equal to 3at%, and the total content of the first metal component is greater than 0at% and less than 10at%; therefore, it can have (a) average grain size at the same time The diameter size can be as fine as 30 microns or less, (b) the uniformity of the average particle size can be controlled below 20%, and (c) the (111) crystal direction strength ratio exceeds 62%. In contrast, the targets of each comparative example cannot simultaneously obtain the above three characteristics (a) to (c), and therefore cannot be applied to the seed layer for sputtering to form a perpendicular magnetic recording medium, nor can the recording of the perpendicular magnetic recording medium be improved as scheduled. density.

It can be seen that the composition of the nickel-tungsten alloy target of Comparative Example 1 and the nickel-iron alloy target of Comparative Examples 3 and 4 are further studied. Because the targets of these comparative examples do not contain the thorium component, the The particle size is coarser than 50 μm, and the uniformity of the grain size is not good, and the strength ratio of the (111) crystal direction is less than 60%. Obviously, it is not possible to obtain a refined and uniform target grain size and improve the crystallinity. And other purposes.

Looking again at the nickel-rhenium alloy targets of Comparative Examples 2, 6, and 7, even if the target contains a rhenium component, if the first metal component is not simultaneously contained, such nickel-rhenium alloy targets still have coarse grains and particle sizes. The problems of poor uniformity and insufficient crystallinity; and from the nickel-rhenium alloy targets of Comparative Examples 8 and 9, it can be seen that even if the nickel-rhenium alloy target contains both nickel, rhenium, and the first metal component, if the first metal component If the content is too high, the aforementioned problems will still exist, and the above three characteristics (a) to (c) cannot be obtained.

For the nickel-rhenium alloy targets of Examples 2, 7 to 12, 14, 16, 17, and 19, when the composition further contains a specific type of second metal component, the total content of the second metal component is further controlled to be greater than 0 at% and less than Or equal to 5at%, and the total content of rhenium, the first metal component and the second metal component is greater than 0at% and less than 10at%, this nickel-rhenium alloy target can also obtain the above three (a) to (c) simultaneously characteristic. In contrast, the nickel-rhenium alloy targets of Comparative Examples 5, 7, 8, 9, 10, and 13 have a total content of rhenium, a first metal component, and a second metal component of more than 10 at%, which makes these nickel-rhenium alloy targets The three characteristics (a) to (c) described above cannot be obtained at the same time. In particular, there is a problem that the crystallinity cannot be improved.

In particular, the composition of the nickel-rhenium alloy targets of Examples 3 to 18 can be seen. When it contains iron, and the iron content is greater than 0at% and less than or equal to 30at%, this nickel-rhenium alloy target can also obtain the foregoing. (a) to (c) Three characteristics.

Based on the analysis results of the above test examples 1 to 3, by controlling the composition of the nickel-rhenium alloy target and its manufacturing method, the present invention can specifically realize the refinement and homogenization of the grain size of the nickel-rhenium alloy target and improve the crystallinity. For this reason, the nickel-rhenium alloy target material created by this invention can be applied to the process of perpendicular magnetic recording media, and is used for sputtering to form a seed layer of the perpendicular magnetic recording medium, thereby improving the recording density of the perpendicular magnetic recording medium.

Claims (10)

A nickel-rhenium alloy target includes nickel, rhenium, and a first metal component. The first metal component includes aluminum, zirconium, or a combination thereof. Based on the total number of atoms of the nickel-rhenium alloy target, the content of rhenium is greater than 0 atomic percent. It is less than or equal to 7 atomic percent, the total content of the first metal component is greater than 0 atomic percent and less than or equal to 3 atomic percent, and the total content of rhenium and the first metal component is greater than 0 atomic percent and less than 10 atomic percent. The nickel-rhenium alloy target according to claim 1, wherein the nickel-rhenium alloy target includes a second metal component, and the second metal component includes titanium, osmium, iridium, yttrium, tantalum, niobium, molybdenum, or a combination thereof. The nickel-rhenium alloy target according to claim 2, wherein based on the total number of atoms of the nickel-rhenium alloy target, the total content of the second metal component is greater than 0 atomic percent and less than or equal to 5 atomic percent; The total content of the first metal component and the second metal component is greater than 0 atomic percent and less than 10 atomic percent. The nickel-rhenium alloy target according to any one of claims 1 to 3, wherein the total content of the first metal component is greater than 0 atomic percent and less than or equal to 2.9 atomic percent. The nickel-rhenium alloy target according to any one of claims 1 to 3, wherein the nickel-rhenium alloy target includes iron, and based on the total number of atoms of the nickel-rhenium alloy target, the iron content is greater than 0 atomic percent and less than Or equal to 30 atomic percent. The nickel-rhenium alloy target according to claim 4, wherein the nickel-rhenium alloy target includes iron, and based on the total number of atoms of the nickel-rhenium alloy target, the iron content is greater than 0 atomic percent and less than or equal to 30 atomic percent. A method for manufacturing a nickel-rhenium alloy target material, comprising: smelting a metal raw material by a vacuum induction melting method under a vacuum environment of 1 × 10 ^-2 Torr to 1 × 10 ^-4 Torr, and a temperature of 1500 ° C to 1750 ° C A pre-alloyed ingot is obtained by casting at a temperature; the pre-alloyed ingot is atomized to obtain a pre-alloyed powder; the pre-alloyed powder is sintered at a sintering temperature of 1000 ° C to 1300 ° C to obtain the nickel-rhenium alloy target The metal raw material contains nickel, hafnium and a first metal component, and the first metal component contains aluminum, zirconium or a combination thereof; based on the total number of atoms of the metal raw material, the content of hafnium is greater than 0 atomic percent and less than or equal to 7 Atomic percentage, the total content of the first metal component is greater than 0 atomic percent and less than or equal to 3 atomic percent, and the total content of rhenium and the first metal component is greater than 0 atomic percent and less than 10 atomic percent. The method according to claim 7, wherein the method for sintering the prealloy powder includes a hot pressing method, a hot equalizing method, or a combination thereof. The method according to claim 7 or 8, wherein the metal raw material further contains a second metal component, and the second metal component contains titanium, osmium, iridium, yttrium, tantalum, niobium, molybdenum, or a combination thereof, and the atom of the metal raw material is Based on the total, the total content of the second metal component is greater than 0 atomic percent and less than or equal to 5 atomic percent, and the total content of rhenium, the first metal component, and the second metal component is greater than 0 atomic percent and less than 10 atomic percent. The method according to claim 7 or 8, wherein the metal raw material further contains iron, and based on the total number of atoms of the metal raw material, the iron content is greater than 0 atomic percent and less than or equal to 30 atomic percent.