Fe-Pt-OXIDE-BN-BASED SINTERED COMPACT FOR SPUTTERING TARGET

Abstract

Provided is an FePt-oxide-BN-based sintered compact for a high-density sputtering target that can suppress generation of particles during sputtering.

The FePt-oxide-BN-based sintered compact for a sputtering target has a mass ratio of N to B (N/B) in a range of 1.300.1.

Claims

1. An FePt-oxide-BN-based sintered compact for a sputtering target, wherein a mass ratio of N to B (NB) is in a range of 1.300.1.

2. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, wherein a relative density measured by the Archimedes method is 92.0% or more.

3. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising 33 mol % or more and 60 mol % or less of Pt and 5 mol % or more and 40 mol % or less of BN and an oxide in total, with the balance being Fe and incidental impurities.

4. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of one or more selected from Co, Zn, Ge, Rh, Ru, and Pd, with the balance being Fe and incidental impurities.

5. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 or 2, comprising 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of C, with the balance being Fe and incidental impurities.

6. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, wherein the oxide is selected from Si oxide, Ti oxide, and Ta oxide.

7. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising: mixing a metal powder, an oxide powder, and a BN powder; and sintering at a temperature of 850 C. or lower.

8. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising: mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

9. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising: strongly mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder and weakly mixing to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

10. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising 33 mol % or more and 60 mol % or less of Pt and 5 mol % or more and 40 mol % or less of BN and an oxide in total, with the balance being Fe and incidental impurities, and wherein the oxide is selected from Si oxide, Ti oxide, and Ta oxide.

11. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of one or more selected from Co, Zn, Ge, Rh, Ru, and Pd, with the balance being Fe and incidental impurities, and wherein the oxide is selected from Si oxide, Ti oxide, and Ta oxide.

12. The FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1, comprising 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of C, with the balance being Fe and incidental impurities and wherein the oxide is selected from Si oxide, Ti oxide, and Ta oxide.

13. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt and 5 mol % or more and 40 mol % or less of BN and an oxide in total, with the balance being Fe and incidental impurities, wherein the method comprising: mixing a metal powder, an oxide powder, and a BN powder; and sintering at a temperature of 850 C. or lower.

14. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt and 5 mol % or more and 40 mol % or less of BN and an oxide in total, with the balance being Fe and incidental impurities, wherein the method comprising: mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

15. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt and 5 mol % or more and 40 mol % or less of BN and an oxide in total, with the balance being Fe and incidental impurities, wherein the method comprising: strongly mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder and weakly mixing to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

16. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of one or more selected from Co, Zn, Ge, Rh, Ru, and Pd, with the balance being Fe and incidental impurities, wherein the method comprising: mixing a metal powder, an oxide powder, and a BN powder; and sintering at a temperature of 850 C. or lower.

17. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of one or more selected from Co, Zn, Ge, Rh, Ru, and Pd, with the balance being Fe and incidental impurities, wherein the method comprising: mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

18. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of one or more selected from Co, Zn, Ge, Rh, Ru, and Pd, with the balance being Fe and incidental impurities and wherein the method comprising: strongly mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder and weakly mixing to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

19. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of C, with the balance being Fe and incidental impurities, wherein the method comprising: mixing a metal powder, an oxide powder, and a BN powder; and sintering at a temperature of 850 C. or lower.

20. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of C, with the balance being Fe and incidental impurities, wherein the method comprising: mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

21. A method of producing the FePt-oxide-BN-based sintered compact for a sputtering target according to claim 1 that comprises 33 mol % or more and 60 mol % or less of Pt, 5 mol % or more and 40 mol % or less of BN and an oxide in total, and 1 mol % or more and 15 mol % or less of C, with the balance being Fe and incidental impurities, wherein the method comprising: strongly mixing an FePt-based alloy powder with an oxide powder to form an oxide-alloy composite powder in which the oxide is finely dispersed within an FePt-based alloy; then adding a BN powder to the oxide-alloy composite powder and weakly mixing to form a BN-containing oxide-alloy composite powder; and subsequently sintering the BN-containing oxide-alloy composite powder at a temperature of 850 C. or lower.

Description

EXAMPLES

[0040] Hereinafter, the present invention will be specifically described by means of the Examples. However, the present invention is not limited to these Examples.

[0041] The measuring methods for the N concentration and B concentration in each Example and Comparative Example are as follows.

[0042] [N Concentration Measurement]

[0043] The N (nitrogen) concentration is measured by using an oxygen/nitrogen determinator (TC-600 from LECO Japan Corporation, thermal conductivity method).

TABLE-US-00001 Output: 5,200 W (2,842 C.) Flux: Ni capsules graphite powder 0.06 g Sn pellets 0.5 g Mass of measuremen sample: 0.1 g Calibration sample: Si.sub.3N.sub.4

[0044] [B Concentration Measurement]

[0045] A sample is ground in a vibration mill, and about 0.1 g of the sample is weighed out and placed in a Zr crucible for alkali fusion. About 0.5 g of sodium carbonate is added to the sample as a fusing agent, the sample and sodium carbonate are ground sufficiently with a stirring rod, and subsequently, about 2.0 g of sodium peroxide is added to the Zr crucible. The Zr crucible is then subjected to heat melting (900 C.) in a high-frequency alkali fusion apparatus, followed by spontaneous cooling. The Zr crucible after cooling is placed in a beaker, immersed in water by adding about 50 mL of pure water, and acidified by adding about 20 mL of concentrated hydrochloric acid. The beaker is then placed on a hot plate and heated for about 1 hour until the sample is completely dissolved to terminate reactions, followed by spontaneous cooling. The solution after cooling is transferred to a 100 mL volumetric flask, and a sample solution of 1,000 ppm (100 mg/100 mL) concentration is prepared. The sample solution is then transferred to a plastic bottle and diluted 25-fold to prepare a measurement solution. The prepared measurement solution is analyzed by ICP (SPECTRO ARCOS ICP-OES analyzer), and the B (boron) concentration (wt %) is calculated from the analyzed result.

[0046] [Relative Density]

[0047] The relative density is measured by the Archimedes method using pure water as an replacement liquid. First, an actual density (g/cm.sup.3) is determined by: measuring the mass of a test piece; measuring a buoyant force (=the volume of the test piece) when the test piece floating on the replacement liquid is fully submerged; and dividing the mass (g) of the test piece by the volume (cm.sup.3) of the test piece. The ratio of the actual density to a theoretical density calculated on the basis of the composition of a sintered compact (actual density/theoretical density) is a relative density.

[0048] [The Number of Particles]

[0049] A sintered compact for a target (diameter of 153 mm, thickness of 2 mm) bonded to a Cu backing plate (diameter of 161 mm, thickness of 4 mm) was fixed to a magnetron sputtering apparatus. After sputtering at an output of 500 W and a gas pressure of 1 Pa for 2 seconds, the number of particles adhered onto a substrate was determined by a particle counter.

Example 1

[0050] To achieve Fe-35Pt-25BN-5SiO.sub.2, 640.00 g of Fe-50Pt atomized powder (average particle size of 50 m), 21.89 g of SiO.sub.2 powder (average particle size of less than 1 m), and 45.22 g of BN powder (average particle size of 15 m) were weighed. First, Fe-50Pt atomized powder (average particle size of 50 m) and SiO.sub.2 powder (average particle size of less than 1 m) were mixed in a ball mill at 450 rpm for 60 hours (vigorous mixing) to form oxide-alloy composite powder. Then, BN powder (average particle size of 15 m) was added to the oxide-alloy composite powder and further mixed at 300 rpm for 5 minutes (weak mixing) to prepare BN-containing oxide-alloy composite powder.

[0051] The BN-containing oxide-alloy composite powder was sintered under vacuum at a sintering temperature of 830 C. and a sintering pressure of 65.60 MPa to yield an FePtSiO.sub.2BN-based sintered compact for a sputtering target. The sintered compact had a relative density measured by the Archimedes method of 98.3%, N/B of 1.25, which is within the theoretical value range of 1.300.1, and the number of particles of 42, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

[0052] Here, the average particle size of the raw material powder is a D.sub.50 value (the same applies to the following Examples and Comparative Examples).

Examples 2 to 6

[0053] Each FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 1 except for changing the composition and sintering temperature as shown in Table 1. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is 96% or more, N/B is 1.29 to 1.38, which is within the theoretical value range of 1.300.1, and the number of particles is 28 or less, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

Example 7

[0054] To achieve Fe-40Pt-10BN-10SiO.sub.2, 146.12 g of Fe powder (average particle size of 6 m), 510.41 g of Pt powder (average particle size of 1 m), 39.30 g of SiO.sub.2 powder (average particle size of less than 1 m), and 16.23 g of BN powder (average particle size of 15 m) were weighed and mixed in a ball mill at 300 rpm for 30 minutes.

[0055] The resulting mixture was sintered under vacuum at a sintering temperature of 780 C. and a sintering pressure of 65.60 MPa to yield an FePtSiO.sub.2BN-based sintered compact for a sputtering target. The sintered compact had a relative density measured by the Archimedes method of 97.0%, N/B of 1.28, which is within the theoretical value range of 1.300.1, and the number of particles of 35, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

Examples 8 and 9

[0056] Each FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 7 except for using TiO.sub.2 (average particle size of 2 m, Example 8) or Ta.sub.2O.sub.5 (average particle size of 3 m, Example 9) as an oxide as well as changing the composition as shown in Table 1. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is 92% or more, N/B is 1.22 to 1.24, which is within the theoretical value range of 1.300.1, and the number of particles is 55 or less, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

Example 10

[0057] To achieve Fe-35Pt-10Co-10BN-10SiO.sub.2, 136.16 g of Fe powder (average particle size of 6 m), 475.64 g of Pt powder (average particle size of 1 m), 41.05 g of Co powder (average particle size of 5 m), 41.86 g of SiO.sub.2 powder (average particle size of less than 1 m), and 17.29 g of BN powder (average particle size of 15 m) were weighed and mixed in a ball mill at 300 rpm for 30 minutes.

[0058] The resulting mixture was sintered under vacuum at a sintering temperature of 780 C. and a sintering pressure of 65.60 MPa to yield an FePtSiO.sub.2-BN-based sintered compact for a sputtering target. The sintered compact had a relative density measured by the Archimedes method of 95.6%, N/B of 1.40, which is within the theoretical value range of 1.300.1, and the number of particles of 15, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

Examples 11 to 15

[0059] Each FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 10 except for using, as an additional metal component, Zn powder (average particle size of 7 m, Example 11), Ge powder (average particle size of 20 m, Example 12), Rh powder (average particle size of 20 m, Example 13), Ru powder (average particle size of 6 m, Example 14), or Pd powder (average particle size of 3 m, Example 15) as well as changing the composition and sintering temperature as shown in Table 1. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is 92% or more, N/B is 1.20 to 1.35, which is within the theoretical value range of 1.300.1, and the number of particles is 40 or less, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

Example 16

[0060] To achieve Fe-35Pt-10BN-10SiO.sub.2-10C, 144.32 g of Fe powder (average particle size of 6 m), 504.13 g of Pt powder (average particle size of 1 m), 44.36 g of SiO.sub.2 powder (average particle size of less than 1 m), 18.33 g of BN powder (average particle size of 15 m), and 8.87 g of C (average particle size of 10 m) were weighed and mixed in a ball mill at 300 rpm for 30 minutes.

[0061] The resulting mixture was sintered under vacuum at a sintering temperature of 780 C. and a sintering pressure of 65.60 MPa to yield an FePt-SiO.sub.2-BN-based sintered compact for a sputtering target. The sintered compact had a relative density measured by the Archimedes method of 92.6%, N/B of 1.26, which is within the theoretical value range of 1.300.1, and the number of particles of 45, which is small. Presumably, decomposition of BN was suppressed, thereby suppressing generation of particles.

Comparative Example 1

[0062] An FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 1 except for changing the sintering temperature to 950 C. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is as low as 87.6% or less, N/B is 1.12 and smaller than the theoretical value of 1.30 by more than 0.1, and the number of particles is 220, which is large. Presumably, BN decomposed, thereby generating nitrogen gas or nitrogen oxide gas.

Comparative Example 2

[0063] An FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 3 except for changing the sintering temperature to 950 C. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is as low as 83.8% or less, N/B is 1.13 and smaller than the theoretical value of 1.30 by more than 0.1, and the number of particles is 189, which is large. Presumably, BN decomposed, thereby generating nitrogen gas or nitrogen oxide gas.

Comparative Example 3

[0064] An FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 5 except for changing the sintering temperature to 950 C. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is as low as 88.1% or less, N/B is 1.05 and smaller than the theoretical value of 1.30 by more than 0.1, and the number of particles is 128, which is large. Presumably, BN decomposed, thereby generating nitrogen gas or nitrogen oxide gas.

Comparative Example 4

[0065] An FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 7 except for changing the sintering temperature to 950 C. as well as the mixing conditions to 300 rpm for 3 hours. The obtained sintered compact had the relative density measured by the Archimedes method of as low as 89.8%, N/B of 1.10, which is smaller than the theoretical value of 1.30 by more than 0.1, and the number of particles of 135, which is large. Presumably, BN decomposed, thereby generating nitrogen gas or nitrogen oxide gas.

Comparative Example 5

[0066] An FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 8 except for changing the sintering temperature to 950 C. as well as the mixing conditions to 300 rpm for 3 hours. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is as low as 90.3% or less, N/B is 1.19 and smaller than the theoretical value of 1.30 by more than 0.1, and the number of particles is 356, which is extremely large. Presumably, BN decomposed, thereby generating nitrogen gas or nitrogen oxide gas.

Comparative Example 6

[0067] An FePt-oxide-BN-based sintered compact for a sputtering target was obtained in the same manner as Example 10 except for changing the sintering temperature to 950 C. as well as the mixing conditions to 300 rpm for 3 hours. The measured results of the relative density, N/B, and the number of particles are shown in Table 1. The relative density is as low as 88.5% or less, N/B is 1.11 and smaller than the theoretical value of 1.30 by more than 0.1, and the number of particles is 114, which is large. Presumably, BN decomposed, thereby generating nitrogen gas or nitrogen oxide gas.

TABLE-US-00002 TABLE 1 Composition and Physical properties of each target Sintering temperature Density N B Particles Composition ( C.) (%) (wt %) (wt %) N/B (count) Ex. 1 Fe35Pt25BN5SiO.sub.2 830 98.3 3.55 2.84 1.25 42 Ex. 2 Fe37.5Pt18BN7SiO.sub.2 830 98.6 2.46 1.85 1.33 28 Ex. 3 Fe40Pt10BN10SiO.sub.2 780 98.8 1.33 0.97 1.37 12 Ex. 4 Fe40Pt8BN12SiO.sub.2 830 98.0 0.99 0.77 1.29 20 Ex. 5 Fe40.5Pt4BN15SiO.sub.2 830 98.0 0.51 0.37 1.38 13 Ex. 6 Fe47Pt3BN3SiO.sub.2 780 96.2 0.38 0.28 1.36 8 Ex. 7 Fe40Pt10BN10SiO.sub.2 780 97.0 1.32 1.03 1.28 35 Ex. 8 Fe40Pt10BN10TiO.sub.2 780 92.8 1.22 1.00 1.22 55 Ex. 9 Fe41.5Pt10BN7Ta.sub.2O.sub.5 780 92.6 0.99 0.80 1.24 35 Ex. 10 Fe35Pt10Co10BN10SiO.sub.2 780 95.6 1.40 1.00 1.40 15 Ex. 11 Fe35Pt10Zn10BN10SiO.sub.2 780 94.4 1.32 1.10 1.20 11 Ex. 12 Fe35Pt10Ge10BN10SiO.sub.2 730 92.2 1.31 1.06 1.24 22 Ex. 13 Fe35Pt10Rh10BN10SiO.sub.2 780 95.3 1.33 1.01 1.32 31 Ex. 14 Fe35Pt10Ru10BN10SiO.sub.2 780 92.3 1.35 1.00 1.35 40 Ex. 15 Fe35Pt10Pd10BN10SiO.sub.2 780 96.4 1.36 1.02 1.33 15 Ex. 16 Fe35Pt10BN10SiO.sub.210C 780 92.6 1.39 1.10 1.26 45 Comp. Ex. 1 Fe35Pt25BN5SiO.sub.2 950 87.6 3.10 2.77 1.12 220 Comp. Ex. 2 Fe40Pt10BN10SiO.sub.2 950 83.8 1.08 0.96 1.13 189 Comp. Ex. 3 Fe40.5Pt4BN15SiO.sub.2 950 88.1 0.39 0.37 1.05 128 Comp. Ex. 4 Fe40Pt10BN10SiO.sub.2 950 89.8 1.06 0.96 1.10 135 Comp. Ex. 5 Fe40Pt10BN10TiO.sub.2 950 90.3 1.12 0.94 1.19 356 Comp. Ex. 6 Fe35Pt10Co10BN10SiO.sub.2 950 88.5 1.14 1.03 1.11 114