TW202342793A - Co-Cr-Pt-B ferromagnetic body sputtering target - Google Patents

Abstract

This Co-Cr-Pt-B ferromagnetic body sputtering target is characterized by comprising: a Co-Cr-Pt-B alloy phase (A) that includes B in the amount of more than 0 at% but not more than 30 at%, where B aggregate phase is not eccentrically located and B is distributed throughout; and an alloy phase (B) which is a Co-B alloy, a Co-Cr-B alloy, or a Co-Pt-B alloy, and which includes B in the amount of more than 0 at% but not more than 20 at%, where B aggregate phase is not eccentrically located and B is distributed throughout. The alloy phase (A) accounts for 50 vol% or more of the sputtering target, and the alloy phase (B) accounts for less than 50 vol% of the sputtering target.

Description

Co-Cr-Pt-B series ferromagnetic sputtering target

The present invention relates to a magnetic film of a magnetic recording medium, in particular to a sputtering target used for forming a magnetic recording layer of a hard disk drive using a perpendicular magnetic recording method, and to sputtering using a magnetron sputtering device. , a sputtering target that can achieve stable discharge at lower voltages.

In the field of magnetic recording represented by hard disk drives, a material system using ferromagnetic metal Co, Fe or Ni as a base is used as a material for the magnetic thin film responsible for recording. In particular, the magnetic recording layer of current hard disk drives uses Co-Pt system or Co-Cr-Pt system, or a system in which non-magnetic inorganic substances are added to these systems. In the production of the magnetic recording layer of the hard disk drive, due to its high productivity, the sputtering method is mainly used in many cases, especially the magnetron sputtering method. As a manufacturing method for target materials that is indispensable when using sputtering methods, dissolution method or powder metallurgy method is generally used. Which of these is used depends on the properties of the target or film required. The sputtering method refers to a method of forming a film by applying a negative voltage to the target in an inert gas environment, so that the atoms constituting the target are deposited on the substrate. By applying a negative voltage, the inert gas is ionized, and the inert gas that becomes cations is attracted to the target and collides with each other, thereby ejecting the atoms constituting the target. The atoms are attached to the surface of the substrate, thereby forming a film on the substrate. The magnetron sputtering method refers to a method in which a magnet is placed on the back side of the target to generate a magnetic field on the target surface to promote the ionization of the plasma gas, thereby improving the sputtering efficiency. In the field of magnetic recording represented by current hard disk drives, the magnetron sputtering method is often used from the viewpoint of its film formation speed, target yield, and sputtering stability. However, the target used for forming the magnetic recording layer is mainly a ferromagnetic material, which hinders the penetration of the magnetic beam emitted from the magnet arranged on the back surface. If the penetration of the magnetic beam is excessively hindered, the above-mentioned advantages of using the magnetron sputtering method will disappear, resulting in a reduction in target yield or destabilization of the sputtering discharge. Therefore, the target used in the magnetron sputtering method is required to have a leakage magnetic flux density as high as possible. In order to increase the leakage magnetic flux density of the target, various methods have been proposed. For example, Japanese Patent No. 4673453 (JP4673453B) describes a ferromagnetic material target, which is characterized in that the structure of the target has a metal matrix (A), and the metal matrix (A) contains more than 90 mol% of Co in the long and short diameters. The difference in diameter is 0~50%, the spherical phase (B) with a diameter of 30~150μm, and is a ferromagnetic material sputtering target composed of a metal with a Cr content of less than 20 mol% and the remainder being Co, and is made of Cr It is a ferromagnetic material sputtering target composed of a metal with a composition of 20 mol% or less, Pt of 5 mol% or more and 30 mol% or less, and the remainder is Co. Specifically, it is described in a ferromagnetic material sputtering target having a composition of 78Co-12Cr-5TiO ₂ -5SiO ₂ , 65Co-13Cr-15Pt-5TiO ₂ -2Cr ₂ O ₃ , 85Co-15Cr, and 70Co-15Cr-15Pt. , the average magnetic flux leakage of the structure containing the spherical Co phase (B) is higher than that of the structure without the spherical Co phase (B). Japanese Patent No. 4758522 (JP4758522B) describes a ferromagnetic material sputtering target, which is characterized by the fact that the structure of the target has a metal matrix (A) and a flat phase containing more than 90wt% Co in the metal matrix (A). (B), the average particle diameter of phase (B) is 10 μm or more and 150 μm or less, and the average aspect ratio is 1:2 to 1:10, and the metal is composed of Cr containing 20 mol% or less and the remainder being Co. Targets whose main components are sputtering targets are metals whose main components are Cr, 20 mol% or less, Pt, 5 mol% or more, 30 mol% or less, and the remainder being Co. Specifically, it is reported that in a ferromagnetic material sputtering target having a composition of 78.73Co-13.07Cr- _8.2SiO2 , the average leakage flux density of an organizer containing a flat Co phase (B) is higher than that using Co atomization The powder (spherical shape) is lower than the original one, but it is higher than the previous one (the details are not clear). Japanese Patent No. 5394576 (JP5394576B) describes a ferromagnetic material sputtering target, which is characterized by the fact that the structure of the target has a metal matrix (A), and the metal matrix (A) contains Pt 40~76 mol% of Co-Pt. Alloy phase (B), and Co alloy phase (C) that is different from Co-Pt alloy phase (B) and contains more than 90 mol% of Co, and is composed of Cr less than 20 mol%, Pt more than 5 mol%, and the remainder is Co A sputtering target made of metal. Specifically, it is described in a ferromagnetic material sputtering target having a composition of 88(Co-5Cr-15Pt)-5CoO-7SiO ₂ and 59Co-6Cr-20Pt-5Ru-4TiO ₂ -4SiO ₂ -2Cr ₂ O ₃ , Compared with an organizer that does not contain Co-Pt alloy phase (B) and Co alloy phase (C), and has a Co-Pt alloy phase (B) containing 81 mol% of Pt at a particle size of 50~150 μm and a particle size of The organizer contains a pure Co phase (C) at 70~150μm, and has a Co-Pt alloy phase (B) containing 50mol% Pt at a particle size of 50~150μm and a pure Co phase (B) at a particle size of 70~150μm. C) The average leakage flux density of the organizer becomes higher. When B is included as an additional element in an amount of 0.5 mol% or more and 10 mol% or less, B may be present in the metal matrix (A) through the Co-Pt alloy phase (B) and the metal matrix (A). The interface or the interface between the Co phase (C) and the metal matrix (A) is slightly diffused in the Co-Pt alloy phase (B) or Co phase (C). That is, B may exist near the interface between the Co-Pt alloy phase (B) or Co phase (C) and the metal matrix (A), but is not distributed in the Co-Pt alloy phase (B) or Co The overall form of phase (C). The above-mentioned previous patent documents all disclose that the performance of the ferromagnetic material sputtering target can be improved by creating a structure in which a Co alloy phase containing more than 90 mol% of large spherical Co with a particle size of 10 μm to 150 μm exists in the metal matrix (A). Leakage flux density. Although it is described that B can be included as an additive element, there is no example including B, and it is unclear whether the desired effect can be obtained in a Co-Cr-Pt-B sputtering target. In addition, it does not reveal or imply that the distribution state of B is controlled, and usually B will be agglomerated and distributed unevenly, so people in the industry will not understand that it has been revealed that B is distributed in the entire body. For Co-Cr-Pt-B sputtering targets that do not contain oxides, the density of the B condensed phase in the metal matrix will become higher. Due to the brittleness of B, microcracks will be generated, which may cause arcing starting from the microcracks. problems occurred. When abnormal discharge occurs due to arc action, sputtering cannot be performed stably and the yield is significantly reduced. As a method of suppressing the arc action of a Co-Cr-Pt-B sputtering target, Japanese Patent Application Publication No. 2015-61946 (JP2015-61946A) describes adjustment by controlling the processing method and heat treatment consisting of precision rolling or forging. The ingot structure composed of Co-Cr-Pt-B alloy is made into a fine and uniform rolled structure without micro cracks. Figure 1 of this publication shows an SEM observation image of the structure of the sputtering target. It is found that it is composed of two phases: a matrix phase and a B-rich phase. The B-rich phase has a cirrocumulus shape. If compared with the SEM observation images of the examples described later, it can be seen that in the sputtering target of the present invention, the B system is distributed across the entire alloy phase, and Figure 1 of the publication shows that B condenses and is unevenly distributed into a rich Contains phase B. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent No. 4673453 (JP4673453B) [Patent Document 2] Japanese Patent No. 4758522 (JP4758522B) [Patent Document 3] Japanese Patent No. 5394576 (JP5394576B ) [Patent Document 4] Japanese Patent Application Publication No. 2015-61946 (JP2015-61946A)

[Problem to be solved by the invention] An object of the present invention is to provide a ferromagnetic sputtering target that can achieve stable discharge without causing abnormal discharge by the magnetron sputtering method. In particular, the object is to provide a Co-Cr-Pt-B based ferromagnetic sputtering target that has a high leakage flux density and can reduce the discharge voltage during sputtering, and a manufacturing method thereof. [Means used to solve problems] The present inventors have found that in a Co-Cr-Pt-B based ferromagnetic sputtering target, B is distributed in both the Co-Cr-Pt alloy phase and the Co or Co-Cr alloy phase, and B is condensed The phase is controlled in such a way that there is no uneven distribution, that is, by creating an alloy phase (B) that includes a Co-Cr-Pt-B alloy phase (A) and either a Co-B alloy or a Co-Cr-B alloy. ) structure can increase the leakage flux density and reduce the discharge voltage, thereby completing the present invention. According to the present invention, a Co-Cr-Pt-B based ferromagnetic sputtering target and a manufacturing method thereof are provided in the following aspects. [1] A Co-Cr-Pt-B based ferromagnetic sputtering target, which is characterized by being composed of alloy phase (A) and alloy phase (B). The alloy phase (A) is a Co-Cr-Pt-B alloy phase (A) that contains more than 0 at% and less than 30 at% of B, and the B condensed phase has no uneven distribution and B is distributed throughout the whole, The alloy phase (B) is any one of Co-B alloy, Co-Cr-B alloy or Co-Pt-B alloy, and contains more than 0at% and less than 20at% of B, and the B condensed phase is not unevenly distributed. B series is distributed throughout the body, The alloy phase (A) accounts for more than 50 vol% of the sputtering target, and the alloy phase (B) accounts for less than 50 vol% of the sputtering target. [2] As the above-mentioned Co-Cr-Pt-B ferromagnetic sputtering target, Cr exceeds 0at% and below 30at%, Pt exceeds 5at% and below 30at%, and B exceeds 0at% and below 25at%. , the remainder is Co and inevitable impurities. [3] The Co-Cr-Pt-B based ferromagnetic sputtering target as described in the above [1] or [2], wherein the aforementioned alloy phase (A) further includes selected from the group consisting of Al, Si, Sc, Ti, V, Mn , Fe, Ni, Cu, Zn, Ge, Y, Zr, Nb, Ta, Mo, W, Ru, Ag, Sn, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Hf 1 Elements exceeding 0at% and less than 25at% are used as added elements. [4] A method for manufacturing a Co-Cr-Pt-B ferromagnetic sputtering target according to any one of the above [1]~[3], which is characterized by including: Co-Cr-Pt-B alloy powder containing B exceeding 0at% and less than 30at%, and A mixing step of weakly mixing any of Co-B alloy powder, Co-Cr-B alloy powder or Co-Pt-B alloy powder containing B exceeding 0at% and less than 20at% to obtain mixed powder; and, A sintering step of sintering the mixed powder to obtain a sintered body. [5] The manufacturing method of [4] above, wherein the aforementioned Co-Cr-Pt-B alloy powder, and the aforementioned Co-B alloy powder, Co-Cr-B alloy powder or Co-Pt-B alloy powder are atomized alloy powder. [6] The manufacturing method of [4] or [5] above, wherein the sintering step is to maintain the mixed powder at a pressure of 10 MPa or more and 100 MPa or less and a temperature of 700°C or more and 1300°C or less for 30 minutes or more and 3 hours. [Effects of the invention] The Co-Cr-Pt-B ferromagnetic sputtering target of the present invention is composed of the Co-Cr-Pt-B alloy phase (A) containing B exceeding 0 at% and not more than 30 at%, and B is distributed throughout the whole body, and B The condensed phase has no uneven distribution and B is distributed across the entire target. Therefore, it can not only reduce the discharge voltage during sputtering, suppress discharge abnormalities such as arcing caused by excess voltage, but also increase the leakage flux density. According to the manufacturing method of the present invention, a Co-Cr-Pt-B based ferromagnetic sputtering target can be obtained, which is made of Co-Cr-Pt-B containing B exceeding 0 at% and not more than 30 at%, and having B distributed throughout the entire body. Alloy phase (A) is an alloy phase that is any one of Co-B alloy, Co-Cr-B alloy or Co-Pt-B alloy and contains more than 0at% and less than 20at% B, and B is distributed throughout It is composed of (B). The B condensed phase has no uneven distribution and B is distributed across the entire target. The leakage magnetic flux density is high, which can reduce the discharge voltage during sputtering.

The invention provides a ferromagnetic sputtering target, which has a high leakage magnetic flux density and can reduce the discharge voltage during sputtering. The Co-Cr-Pt-B ferromagnetic sputtering target of the present invention is characterized by being composed of an alloy phase (A) and an alloy phase (B). The alloy phase (A) contains B exceeding 0at% and 30at%. % or less, and the B condensed phase has no uneven distribution and B is distributed in the entire Co-Cr-Pt-B alloy phase (A). The alloy phase (B) is Co-B alloy, Co-Cr-B alloy or Any Co-Pt-B alloy that contains more than 0 at% and less than 20 at% B, and the B condensed phase is not unevenly distributed but B is distributed throughout the whole, and the alloy phase (A) accounts for 50vol in the sputtering target % or more, the alloy phase (B) accounts for less than 50vol% of the sputtering target. In the Co-Cr-Pt-B based ferromagnetic sputtering target of the present invention, the alloy phase (A) is more than the alloy phase (B), and the alloy phase (A) accounts for more than 50 vol%, preferably more than 60 vol%, and more Preferably, it accounts for more than 65 vol%, and the alloy phase (B) is less than 50 vol%, more preferably less than 40 vol%, more preferably less than 35 vol%. The Co-Cr-Pt-B ferromagnetic sputtering target of the present invention is composed of two phases: alloy phase (A) and alloy phase (B), and does not contain other phases such as oxide phases. The aforementioned alloy phase (A) contains B exceeding 0 at% and not more than 30 at%, preferably not less than 3 at% and not more than 26 at%, and the aforementioned alloy phase (B) includes B exceeding more than 0 at% and not more than 20 at%, preferably not less than 3 at% and not more than 18.5 at%. the following. In the alloy phase (B), "B is distributed throughout the whole" means the EPMA-WDX map at a SEM observation surface of 1000 times, an acceleration voltage of 20 kV, an irradiation current of 8×10 ^-5 A, a beam diameter of 10 μm, and an observation magnification of 200 times. In the image, there is no place where B does not exist in any 10 μm × 10 μm area. Furthermore, it is preferable that B is distributed throughout the alloy phase (A). Here, "B is distributed throughout the entire alloy phase (A)" refers to EPMA-WDX under an SEM observation surface of 1000 times, an accelerating voltage of 20 kV, an irradiation current of 8×10 ^-5 A, a beam diameter of 10 μm, and an observation magnification of 200 times. In the mapping image, there is no place where B does not exist in any 10 μm × 10 μm area. The Co-Cr-Pt-B ferromagnetic sputtering target of the present invention has Cr exceeding 0at% and less than 30at%, Pt exceeding 5at% and less than 30at%, B exceeding 0at% and less than 25at%, and the remainder is The composition of Co and unavoidable impurities is preferred. In particular, it is preferable to have a composition in which Cr is not less than 3at% and not more than 25at%, Pt is not less than 10at% and not more than 25at%, B is not less than 3at% and not more than 20at%, and the remainder is Co and inevitable impurities. The aforementioned alloy phase (A) may further include selected from the group consisting of Al, Si, Sc, Ti, V, Mn, Fe, Ni, Cu, Zn, Ge, Y, Zr, Nb, Te, Mo, W, Ru, Ag, Sn , La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Hf, one or more elements exceeds 0at% and less than 25at%, and preferably contains 1at% or more and 15at% or less as an added element. In the present invention, the average composition of the alloy phase (A) and the alloy phase (B) is measured by the following method. Cut out a vertical section relative to the sputtering target, polish it sequentially using abrasive papers numbered from P80 to P1200, and finally obtain a polished surface by using diamond abrasive grains with a particle size of 1 μm for buff polishing. . This polished surface was observed using EPMA. The observation conditions of EPMA are to use JXA-8500F manufactured by JEOL as the device, and set the acceleration voltage to 20kV, the irradiation current to 8×10 ^-5 A, the beam diameter to 10μm, the observation magnification to 200×, and the number of pixels to 128×128 to obtain the element map. picture. When observing, use the quantitative analysis mode, select metal as the measurement substance, and select the ZAF method as the correction method. In the obtained element mapping image, it was confirmed that all main components of Co, Cr, Pt, and B phases (corresponding to the alloy phase (A)) were detected, and no Cr, Pt, or ratio was detected. After removing Cr or Pt in the alloy phase (A) or the extremely low concentration phase (corresponding to the alloy phase (B)), select a location that can fully accommodate a true circle with a diameter of 50 μm, and measure its center of gravity. composition. The above observations were carried out at three locations for each of the three viewing areas, alloy phase (A), and alloy phase (B), and the average was used as the average composition of the alloy phase (A) and the alloy phase (B). In the present invention, the volume ratio of the alloy phase (A) and the alloy phase (B) is measured by the following method. First, EPMA is used to obtain the mass concentration map of each element through the above method. Using the obtained mass concentration map, for the undetected elements in the alloy phase (B) (for example, Cr or Pt in the case of Co-B, Pt in the case of Co-Cr-B), from the end of the image to the other Perform horizontal line analysis to the end. During online analysis, among the phases corresponding to the aforementioned alloy phase (A) and alloy phase (B), select a location outside the boundary between alloy phase (A) and alloy phase (B), that is, select a location that contains only the alloy phase. The line between the area of (A) and the area of only the alloy phase (B). The graph is binarized by setting the average value of the maximum value and the minimum value of the profile obtained by line analysis as a threshold value. Here, the range exceeding the threshold value is defined as alloy phase (A), and the range below the threshold value is defined as alloy phase (B). The obtained binary image was analyzed using particle analysis in ImageJ to determine the area ratio of the alloy phase (A) and the alloy phase (B). The above operation is performed for 3 visual field points, and the average value is used as the area ratio of the sample. The area ratio is directly related to the volume ratio of the individual phase. Basically, Pt is used as the element used for line analysis of the mass concentration diagram, but when Pt is included in all phases, Cr is used. The Co-Cr-Pt-B based ferromagnetic sputtering target of the present invention can be manufactured by powder metallurgy. The manufacturing method of the present invention includes: combining Co-Cr-Pt-B alloy powder containing B exceeding 0at% and 30at% or less, and Co-B alloy powder containing B exceeding 0at% and 20at% or less, Co-Cr-B A step of weakly mixing either alloy powder or Co-Pt-B alloy powder to obtain a mixed powder, and a step of sintering the mixed powder to obtain a sintered body. The aforementioned Co-Cr-Pt-B alloy powder, Co-B alloy powder, Co-Cr-B alloy powder or Co-Pt-B alloy powder can be produced by using atomized alloy powder, chemical production methods or other production methods. The powder produced is preferably atomized alloy powder. Weak mixing does not mean that a large amount of mixing and stirring energy is given to pulverize each raw material powder, but means that the Co-Cr-Pt-B alloy powder constituting the alloy phase (A) is not mixed with the Co-Cr-Pt-B alloy powder constituting the alloy phase (B). The Co-B alloy powder, Co-Cr-B alloy powder or Co-Pt-B alloy powder is pulverized, and each alloy powder is retained and mixed slowly. In the manufacturing method of the present invention, when a ball mill is used for weak mixing, it is preferable to achieve a small rotation number and a short time mixing, for example, a rotation number of 30 rpm or more and 100 rpm or less and 10 minutes or more and 1 hour or less. It is preferable to use only up, down, left, and right It is best to shake without using a vibrator or mixer with a mixing ball. The sintering system can be carried out in a vacuum environment at a sintering pressure of 10MPa or more and 100MPa or less, a sintering temperature of 700°C or more and a range of 1300°C or more, and a holding time of 30 minutes or more and 3 hours or more. Preferably, the sintering pressure is 20MPa or more and 80MPa or less, and the sintering temperature is 800°C or more. Below 1100℃, the holding time should be between 30 minutes and 2 hours. When the sintering pressure is too low, the density of the sintered body will decrease. When the sintering temperature is too low, the density of the sintered body decreases. On the contrary, when the sintering temperature is too high, B will be excessively agglomerated to form a coarse B agglomerated phase as found in the previous technology, and B will not be distributed throughout the target and easily uneven distribution. If the sintering holding time is too short, the density of the sintered body will decrease. On the contrary, if the sintering holding time is too long, B will easily agglomerate to form a coarse B agglomerated phase as found in the previous technology, and B will not be distributed throughout the target. And easily distributed unevenly. This reduction in density can cause particles to be generated from the target during sputtering discharge. On the other hand, the uneven distribution of the coarse B condensed phase may cause discharge failure including arcing. [Examples] Hereinafter, the present invention will be explained more specifically through Examples and Comparative Examples, but the present invention is not limited thereto. In Examples 1 to 23, the atomized alloy powder of the raw material constituting the alloy phase (A) shown in Table 1 was mixed with the atomized alloy powder constituting the second phase shown in Table 1 (Example (meaning alloy phase (B), the same below), the atomized alloy powder of the raw material is weighed in such a way that it becomes the second phase content shown in Table 1 and the remainder is the alloy phase (A) content, using a vibrator at 15~ Mix at 100 rpm for 15 minutes, fill the obtained mixed powder into a carbon mold, and perform vacuum hot pressing in a vacuum environment at a pressure of 30 MPa, a temperature of 800°C ~ 1100°C, and a holding time of 1 hour for sintering. The sintering temperature varies depending on the target composition, but is set so that the density becomes 97% or more for all samples. The obtained sintered body was cut and ground using a flat grinding disc and a rotating disc to produce a disc-shaped sputtering target with a diameter of 165 mm and a thickness of 6.4 mm. The obtained disc-shaped sputtering target is installed in the magnetron sputtering device, argon gas is circulated so that the argon gas pressure becomes 4.0 Pa, sputtering discharge is continued with arbitrary input power, and the sputtering is measured using a data recorder. Plating discharge voltage. The setting conditions of the data logger are such that the sampling period is 2 μ seconds and the data measured at 15,000 points is repeated 100 times. Calculate the average of the data of each measurement, and average the average value 100 times to calculate the sputtering discharge voltage value under the measurement conditions. The results are shown in Table 1. Comparative Examples 1, 5, 7, 9, 11, and 13 were sputtering targets produced in the same manner as in the Examples except that the alloy atomized powder was not mixed but each metal powder was mixed to prepare a mixed powder. In Comparative Examples 2 and 3, a sputtering target was produced in the same manner as in the Example, except that atomized alloy powder not containing B was used as the raw material powder constituting the second phase. Comparative Examples 4, 6, 8, 10, 12 and 14 were sputtering targets produced in the same manner as in the Examples except that Co metal powder was used as the raw material powder constituting the second phase. The results of measuring the sputtering discharge voltage were measured by changing the input power from 100W to 1000W every 100W for the sputtering targets of Examples 1 to 3 and Comparative Examples 1 to 4 having the same composition of Co-15Cr-10Pt-10B. Shown in Table 2 and Figure 1. The measured values of PTF (leakage flux density) are also recorded in Table 2. The measurement of PTF is carried out according to ASTM F2086-01. It was confirmed that the PTF of the sputtering targets of Examples 1 and 2 was higher than that of the sputtering targets of Comparative Examples 1 and 2, but was equivalent to the PTF of the sputtering target of Comparative Example 3. The sputtering target of Example 3 The PTF is higher than that of any of the sputtering targets of Comparative Examples 1 to 4, and the leakage flux density can also be improved. As can be seen from Figure 1, when arranged in order of high and low sputtering discharge voltages, it becomes Comparative Example 4 using Co metal powder as the second phase. It is produced using each metal powder instead of alloy atomized powder. Comparative Example 1, Comparative Examples 3 and 2 produced using atomized alloy powder that does not contain B as the second phase, and Examples 1 to 3 in which B is dispersed across the entire alloy phase (A) and alloy phase (B) The sputtering discharge voltage is significantly lower than that of Comparative Examples 1 to 4. In particular, if the input power exceeds 300W, the reduction in the sputtering discharge voltage becomes larger. In addition, it can be seen from Table 1 that if the sputtering discharge voltage is compared when the input power is 500W, the Example has a low value of 330V or less, but the Comparative Example has a high value exceeding 330V. SEM observation images (15.0V×1,000) of the sputtering targets of Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Figures 2 to 7. The EPMA-WDX mapping images (15.0V×2,000) are shown in Figures 8~13. It can be seen from the EPMA-WDX mapping image of Figure 8 that the white area below the CP image of the sputtering target of Example 1 is the Co-Cr-Pt-B alloy phase containing Co, Cr, Pt and B ( A), the upper gray area in the CP image is the Co-Pt-B alloy phase (B) containing Co, Pt and B. It can be seen from Figure 2 and Figure 8 that the sputtering target of Example 1 is composed of Co-Cr-Pt-B alloy phase (A) and Co-Pt-B alloy phase (B). B is in the alloy phase. In both (A) and (B), there is no place that does not exist in any 10 μm × 10 μm area. B is distributed throughout the alloy phase (A) and the alloy phase (B), and the alloy phase (A) The B in the alloy phase (B) is finely and evenly distributed throughout the alloy phase (B). Although the B in the alloy phase (B) is agglomerated compared to the B in the alloy phase (A), it is still distributed throughout the alloy phase (B). It can be seen from the EPMA-WDX mapping image of Figure 9 that the white area on the right side of the CP image of the sputtering target of Example 2 is a Co-Cr-Pt-B alloy phase containing Co, Cr, Pt and B. (A), the gray area on the left in the CP image is the Co-Cr-B alloy phase (B) containing Co, Cr and B. It can be seen from Figure 3 and Figure 9 that the sputtering target of Example 2 is composed of Co-Cr-Pt-B alloy phase (A) and Co-Cr-B alloy phase (B). B is in the alloy phase. In both (A) and (B), there is no place that does not exist in any 10 μm × 10 μm area. B is distributed throughout the alloy phase (A) and the alloy phase (B), and the alloy phase (A The B in the alloy phase (B) is finely and evenly distributed throughout the entire alloy phase (B). Although the B in the alloy phase (B) is agglomerated compared to the B in the alloy phase (A), it is still distributed throughout the alloy phase (B). It can be seen from the EPMA-WDX mapping image in Figure 10 that the white area above the CP image of the sputtering target of Example 3 is the Co-Cr-Pt-B alloy phase (A) containing Co, Cr, Pt and B. ), the lower gray area in the CP image is the Co-B alloy phase (B) containing Co and B. It can be seen from Figure 4 and Figure 10 that the sputtering target of Example 3 is composed of Co-Cr-Pt-B alloy phase (A) and Co-B alloy phase (B). B is in the alloy phase (A ) and (B), there is no place that does not exist in any 10 μm × 10 μm area. B is distributed throughout the alloy phase (A) and the alloy phase (B), and within the alloy phase (A) The B is distributed throughout the alloy phase (B). Although the B in the alloy phase (B) is condensed compared to the B in the alloy phase (A), it is still distributed throughout the alloy phase (B). As can be seen from Figures 5 and 11, the sputtering target of Comparative Example 1 has a single phase in which Co, Cr, Pt, and B are dispersed throughout, and does not have an alloy phase (B). It can be seen from the EPMA-WDX mapping image in Figure 12 that the gray area on the right in the CP image of the sputtering target of Comparative Example 2 is the Co-Pt phase that contains Co and Pt but does not contain B. CP image The area with black dots on the left center is the Co-Cr-Pt-B phase (A) containing Co, Cr, Pt and B. As can be seen from Figures 6 and 12, the sputtering target of Comparative Example 2 is composed of the Co-Cr-Pt-B phase (A) and the Co-Pt phase (second phase), but in the Co-Pt phase There is no B in and there is no alloy phase (B) containing B. It can be seen from the EPMA-WDX mapping image in Figure 13 that the white area in the lower right corner of the CP image of the sputtering target of Comparative Example 3 is the Co-Cr-Pt-B phase containing Co, Cr, Pt and B. (A), The gray area in the upper left corner of the CP image is the Co-Pt phase containing Co and trace amounts of Pt. The larger black area in the same gray area is the coarse B condensed phase distributed unevenly around Co. It can be seen from Figures 7 and 13 that the sputtering target of Comparative Example 3 is composed of the Co-Cr-Pt-B phase (A) and the Co-Pt phase (second phase), and the B system is unevenly distributed. Around the Co-Pt phase, there is a 10 μm × 10 μm area in the second phase in which B does not exist, and there is no alloy phase (B) in which B is distributed throughout.

[Fig. 1] A graph showing the relationship between input power and voltage value in Examples 1 to 3 and Comparative Examples 1 to 4. [Fig. 2] SEM observation image of Example 1. [Fig. 3] SEM observation image of Example 2. [Fig. 4] SEM observation image of Example 3. [Fig. 5] SEM observation image of Comparative Example 1. [Fig. 6] SEM observation image of Comparative Example 2. [Fig. 7] SEM observation image of Comparative Example 3. [Fig. 8] EPMA-WDX mapping image of Example 1. [Fig. 9] EPMA-WDX mapping image of Example 2. [Fig. 10] EPMA-WDX mapping image of Example 3. [Fig. 11] EPMA-WDX mapping image of Comparative Example 1. [Figure 12] EPMA-WDX mapping image of Comparative Example 2. [Fig. 13] EPMA-WDX mapping image of Comparative Example 3.

Claims (6)

A Co-Cr-Pt-B based ferromagnetic sputtering target, which is characterized by being composed of alloy phase (A) and alloy phase (B). The alloy phase (A) is a Co-Cr-Pt-B alloy phase (A) that contains more than 0 at% and less than 30 at% of B, and the B condensed phase has no uneven distribution and B is distributed throughout the whole, The alloy phase (B) is any one of Co-B alloy, Co-Cr-B alloy or Co-Pt-B alloy, and contains more than 0at% and less than 20at% of B, and the B condensed phase is not unevenly distributed. B series is distributed throughout the body, The alloy phase (A) accounts for more than 50 vol% of the sputtering target, and the alloy phase (B) accounts for less than 50 vol% of the sputtering target. For example, the Co-Cr-Pt-B ferromagnetic sputtering target in claim 1 has Cr exceeding 0at% and below 30at%, Pt is above 5at% and below 30at%, B exceeds 0at% and below 25at%, and the remainder is Co. and unavoidable impurities. Such as the Co-Cr-Pt-B based ferromagnetic sputtering target of claim 1 or 2, wherein the aforementioned alloy phase (A) further includes selected from the group consisting of Al, Si, Sc, Ti, V, Mn, Fe, Ni, Cu , Zn, Ge, Y, Zr, Nb, Ta, Mo, W, Ru, Ag, Sn, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Hf exceed 0at% And less than 25at% as added elements. A method for manufacturing a Co-Cr-Pt-B ferromagnetic sputtering target according to any one of claims 1 to 3, characterized by comprising: Co-Cr-Pt-B alloy powder containing B exceeding 0at% and less than 30at%, and A mixing step of weakly mixing any of Co-B alloy powder, Co-Cr-B alloy powder or Co-Pt-B alloy powder containing B exceeding 0at% and less than 20at% to obtain mixed powder; and, A sintering step of sintering the mixed powder to obtain a sintered body. The manufacturing method of claim 4, wherein the aforementioned Co-Cr-Pt-B alloy powder, and the aforementioned Co-B alloy powder, Co-Cr-B alloy powder or Co-Pt-B alloy powder are atomized alloy powder. Such as the manufacturing method of Claim 4 or 5, wherein the aforementioned sintering step is to maintain the aforementioned mixed powder at a pressure of not less than 10 MPa and not more than 100 MPa, and a temperature of not less than 700°C and not more than 1300°C for 30 minutes but not more than 3 hours.