Alloy Suitable for Sputtering Target Material

Abstract

A problem to be solved by the present invention is to provide an alloy that is suitable for a sputtering target material and easy to be produced by an atomization method, and, in order to solve the problem. The present invention provides an alloy containing: at least one selected from Co and Fe; B; C; and the balance being unavoidable impurities. A concentration of C in the alloy is 50 ppm or more and 950 ppm or less, and where a composition of Co, Fe and B, excluding C and the unavoidable impurities, in the alloy is represented by the general formula: (Co.sub.X-Fe.sub.100-X).sub.100-Y-B.sub.Y, where X is 0 or more and 100 or less, and Y is 10 or more and 65 or less.

Claims

1. An alloy consisting of: at least one selected from Co and Fe; B; C; and the balance being unavoidable impurities, wherein: a concentration of C in the alloy is 200 mass ppm or more and 950 mass ppm or less; and assuming that a total number of Co, Fe and B atoms in the alloy is 100, a composition of Co, Fe and B, excluding C and the unavoidable impurities, in the alloy is represented by the general formula:
(Co.sub.X-Fe.sub.100-X).sub.100-Y-B.sub.Y wherein X is 0 or more and 100 or less, and Y is 10 or more and 65 or less.

2. An alloy consisting of: at least one selected from Co and Fe; B; C; an additional metal element M; and the balance being unavoidable impurities, wherein: a concentration of C in the alloy is 200 mass ppm or more and 950 mass ppm or less; assuming that a total number of Co, Fe, B and M atoms in the alloy is 100, a composition of Co, Fe, B and M, excluding C and the unavoidable impurities, in the alloy is represented by the general formula:
(Co.sub.X-Fe.sub.100-X).sub.100-Y-Z-B.sub.Y-M.sub.Z wherein X is 0 or more and 100 or less, Y is 10 or more and 65 or less, and Z is 0.5 or more and 30 or less; and the metal element M consists of one or more selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Ru, Rh, Ir, Ni, Pd, Pt, Cu and Ag.

3. A sputtering target material obtained by using the alloy according to claim 1.

4. A sputtering target material obtained by using the alloy according to claim 2.

Description

EXAMPLES

[0034] The effect of the present invention will be now demonstrated with reference to Examples. However, the present invention should not be construed as being limited to the descriptions of the Examples.

Production of Alloy Powder

[0035] In order to obtain the compositions shown in Tables 1 to 3, the raw materials were each weighed, introduced into a crucible composed of a refractory material, and molten by induction heating under reduced pressure in an Ar gas atmosphere. Then, the molten materials were allowed to flow out through the small orifice (having a diameter of 8 mm) provided in the lower portion of the crucible, and gas-atomized by using a high-pressure Ar gas to yield an alloy powder in each of Examples (Nos. 1 to 45) and an alloy powder in each of Comparative Examples (Nos. 46 to 49). The carbon concentration in each alloy powder was adjusted by addition a carbon powder in consideration of the amount of carbon contained in the raw materials, and measured by a non-dispersive infrared absorption method. In this regard, note that “100-X”, which means the amount of Fe, is omitted from each of the compositions shown in Tables 1 to 3.

Atomizability

[0036] To the composition in each of the Examples (Nos. 1 to 45) and the Comparative Examples (Nos. 46 to 49), gas-atomization was applied five times under the same conditions, and the presence or absence and degree of occlusion in the small orifice of the crucible was observed. The number of times when an alloy powder was obtained without occluding the small orifice during atomization is expressed as the number of successes in Tables 1 to 3. The number of successes is rated on the basis of the following criteria, and expressed as A or B in Tables 1 to 3

[0037] A (excellent atomizability): the number of successes is three or more.

[0038] B (poor atomizability): the number of successes is two or less.

TABLE-US-00001 TABLE 1 Composition Atomizability (Co.sub.X—Fe.sub.100−X).sub.100−Y−Z—B.sub.Y—M.sub.Z (at %) Carbon Number (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Ru, Rh, Ir, Ni, Pd, Pt, Cu, Ag) Concen- of Evalu- Example X Y Z tration Suc- ation No. Co B Total Ti Zr Hf V Nb Ta Cr Mo W Mn Re Ru Rh Ir Ni Pd Pt Cu Ag (ppm) cesses Results 1 0 10 0 — — — — — — — — — — — — — — — — — — — 50 5 A 2 10 30 0 — — — — — — — — — — — — — — — — — — — 50 5 A 3 30 40 0 — — — — — — — — — — — — — — — — — — — 60 5 A 4 35 20 0 — — — — — — — — — — — — — — — — — — — 50 5 A 5 50 20 0 — — — — — — — — — — — — — — — — — — — 100 5 A 6 70 20 0 — — — — — — — — — — — — — — — — — — — 50 5 A 7 75 50 0 — — — — — — — — — — — — — — — — — — — 50 5 A 8 80 60 0 — — — — — — — — — — — — — — — — — — — 950 5 A 9 90 65 0 — — — — — — — — — — — — — — — — — — — 500 5 A 10 100 40 0 — — — — — — — — — — — — — — — — — — — 300 5 A 11 35 20 0.5 0.5 — — — — — — — — — — — — — — — — — — 100 5 A 12 50 20 1 — 1 — — — — — — — — — — — — — — — — — 100 5 A 13 75 20 10 — — 10 — — — — — — — — — — — — — — — — 50 5 A 14 80 30 20 — — — 20 — — — — — — — — — — — — — — — 80 4 A 15 20 10 5 — — — — 5 — — — — — — — — — — — — — — 60 5 A 16 10 10 8 — — — — — 8 — — — — — — — — — — — — — 90 5 A 17 50 10 30 — — — — — — 30 — — — — — — — — — — — — 100 5 A 18 30 30 11 — — — — — — — 11 — — — — — — — — — — — 50 5 A 19 35 30 10 — — — — — — — — 10 — — — — — — — — — — 50 4 A 20 20 20 20 — — — — — — — — — 20 — — — — — — — — — 50 5 A 21 25 50 3 — — — — — — — — — — 3 — — — — — — — — 90 5 A 22 75 20 3 — — — — — — — — — — — 3 — — — — — — — 100 5 A 23 80 40 5 — — — — — — — — — — — — 5 — — — — — — 130 5 A

TABLE-US-00002 TABLE 2 Composition Atomizability (Co.sub.X—Fe.sub.100−X).sub.100−Y−Z—B.sub.Y—M.sub.Z (at %) Carbon Number (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Ru, Rh, Ir, Ni, Pd, Pt, Cu, Ag) Concen- of Evalu- Example X Y Z tration Suc- ation No. Co B Total Ti Zr Hf V Nb Ta Cr Mo W Mn Re Ru Rh Ir Ni Pd Pt Cu Ag (ppm) cesses Results 24 90 20 3 — — — — — — — — — — — — — 3 — — — — — 250 5 A 25 50 22 3 — — — — — — — — — — — — — — — 3 — — — 210 5 A 26 30 22 1 — — — — — — — — — — — — — — — — 1 — — 200 5 A 27 20 25 30 5 5 — — — — — — — — — — — — — — — 20 — 220 5 A 28 10 65 15 5 — 5 — — — — — — — — — — — — — — — 5 850 5 A 29 0 23 5 5 — — — — — — — — — — — — — — — — — — 220 3 A 30 0 50 15 5 — — — 10 — — — — — — — — — — — — — — 950 5 A 31 100 40 10 5 — — — — — — 5 — — — — — — — — — — — 100 5 A 32 100 30 6 5 — — — — — — — — — 1 — — — — — — — — 150 5 A 33 80 15 6 5 — — — — — — — — — — 1 — — — — — — — 200 5 A 34 60 13 8 5 — — — — — — — — — — — 3 — — — — — — 120 5 A 35 20 14 8 5 — — — — — — — — — — — — 3 — — — — — 110 5 A 36 20 18 7 5 — — — — — — — — — — — — — — 2 — — — 130 5 A 37 25 19 14 — 5 — 5 — — — 2 — — 1 — — — — — 1 — — 150 5 A 38 30 20 5 — — — — — — — — — — — — — — — — — 5 — 140 4 A 39 30 22 8 — — — — — — — — — — — — — — — — — — 8 130 5 A 40 40 24 10 — — — — — 5 — — — 5 — — — — — — — — — 120 5 A 41 30 10 30 5 — — — — — 15 — — — 5 3 2 — — — — — — 220 5 A 42 75 10 30 — — — 5 — 10 10 — — — — — — — — — — — 5 150 5 A 43 25 10 30 — 6 — — — — — — 4 10 — — — — — — — 10 — 200 5 A 44 50 22 18 1 1 1 1 1 1 1 1 1 1 1 1 1 1 — 1 1 1 1 110 4 A 45 20 30 10 — — — — — — — — — — — — — — 10 — — — — 190 5 A

TABLE-US-00003 TABLE 3 Composition Atomizability Compar- (Co.sub.X—Fe.sub.100−X).sub.100−Y−Z—B.sub.Y—M.sub.Z (at %) Carbon Number ative (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Ru, Rh, Ir, Ni, Pd, Pt, Cu, Ag) Concen- of Evalu- Example X Y Z tration Suc- ation No. Co B Total Ti Zr Hf V Nb Ta Cr Mo W Mn Re Ru Rh Ir Ni Pd Pt Cu Ag (ppm) cesses Results 46 0 10 0 — — — — — — — — — — — — — — — — — — — 20 2 B 47 70 20 0 — — — — — — — — — — — — — — — — — — — 20 1 B 48 75 20 10 — — 10 — — — — — — — — — — — — — — — — 40 1 B 49 40 24 10 — — — — — 5 — — — 5 — — — — — — — — — 30 2 B

[0039] As shown in Tables 1 to 3, in each of the Examples (Nos. 1 to 45), the carbon concentration was adjusted to 50 to 950 ppm, and thus the number of successes in gas atomization was large, exhibiting excellent atomizability. On the other hand, in the Comparative Examples (Nos. 46 to 49), the carbon concentration was less than 50 ppm, and thus the number of successes in gas atomization was small, exhibiting poor atomizability. In the experimental examples carried out by using the carbon concentration of more than 950 ppm (the experimental examples are not shown in Tables 1 to 3), bubbles were generated in the crucible, thus failing to afford a desired powder.

Production of Sputtering Target Material

[0040] The alloy powder in each of the Examples (Nos. 1 to 45) was used to produce a sputtering target material by the following procedure.

[0041] First, the alloy powder obtained by the gas atomization method was subject to sieve classification to remove coarse particles having a diameter of 500 pm or more. Next, the powder after the sieve classification was packed into a can (having an outer diameter of 220 mm, an inner diameter of 210 mm, and a length of 200 mm) formed of carbon steel, and subjected to vacuum degassing and then to an HIP method to yield a sintered product. The conditions for HIP were as follows. [0042] Temperature: 1100° C. [0043] Pressure: 200 MPa [0044] Retention time: 3 hours

[0045] The resulting sintered product was wire-cut, lathed, and surface-ground to be processed into a disc-shaped sputtering target material having a diameter of 180 mm and a thickness of 7 mm.

Sputtering Quality

[0046] The sputtering target material produced by using the powder in each of the Examples (Nos. 1 to 45) was used for sputtering, and the target material after the sputtering was visually checked for any crack.

[0047] No crack was observed in any of the target materials. By using any of the target materials, a thin film having a generally uniform thickness was formed on a substrate. These evaluation results have revealed that a target material having a carbon concentration of 50 ppm or more and 950 ppm or less enables good sputtering.

[0048] As described above, the alloys in the Examples are evaluated better than the alloys in the Comparative Examples. These evaluation results have clarified the superiority of the present invention.

[0049] As described above, the alloy suitable for a sputtering target material and the sputtering target material formed from the alloy can be used in various applications in which a thin film composed of a Co—Fe—B-based alloy is used.