NiW(X) Sputtering Target with Improved Structure

Abstract

The present invention relates to a sputtering target comprising Ni, W and, optionally, one or more further metal(s) X selected from the group of the refractory metals, Sn, Al and Si, which has a normalized peak intensity ratio

PIR=I.sub.Ni/I.sub.w.Math.(A.sub.w+A.sub.x)/A.sub.NI of 0.40 or greater, wherein I.sub.Ni is the intensity of the (111) peak of Ni, I.sub.w is the intensity of the (110) peak of W, A.sub.w is the fraction of W in the target in atom %, A.sub.x is the total fraction of the one or more further metals selected from the group of the refractory metals, Sn, Al and Si in the target in atom %, A.sub.Ni is the fraction of Ni in the target in atom %, and wherein the intensities of the peaks are determined by X-ray powder diffraction using Cu-K.sub.alpha radiation.

Claims

1. Sputtering target comprising Ni, W and, optionally, one or more further metal(s) X selected from the group of the refractory metals, Sn, Al and Si, which has a normalized peak intensity ratio
PIR=I.sub.Ni/I.sub.w (A.sub.w+A.sub.x)/A.sub.Ni of 0.40 or greater, wherein I.sub.Ni is the intensity of the (111) peak of Ni, I.sub.w is the intensity of the (110) peak of W, A.sub.w is the fraction of W in the target in atom %, A.sub.x is the total fraction of the one or more further metals selected from the group of the refractory metals, Sn, Al and Si in the target in atom %, A.sub.Ni is the fraction of Ni in the target in atom %, and wherein the intensities of the peaks are determined by X-ray powder diffraction using Cu-K.sub.alpha radiation.

2. Sputtering target according to claim 1 wherein the normalized peak ratio is 0.42 or greater.

3. Sputtering target according to claim 1 wherein the atom ratio Ni/W in the sputtering target is from 0.5 to 10.

4. Sputtering target according to claim 1 wherein the optional further metal X is selected from the group of the refractory metals.

5. Sputtering target according to claim 1 wherein the optional further metal X is selected from the group of Ta, Nb and Mo.

6. Sputtering target according to claim 1 wherein the optional further metal X is Ta.

7. Sputtering target according to claim 1 wherein Ni is present in an amount of from 45 to 90 atom %.

8. Sputtering target according to claim 1 wherein W is present in an amount of from 7 to 50 atom %.

9. Sputtering target according to claim 1 wherein X is present in an amount of from 3 to 20 atom %.

Description

EXAMPLES

[0057] Several examples and comparative examples were performed in order to illustrate the invention. Spray powders were prepared by blending elemental powders in a tubular blender for 3 h. Typically, powders with a grain size range of 30 to 120 μm give suitable results. Especially for W too large grains should be avoided. These powder blends were used for plasma spraying on SST tubes with an OD of 133 mm and a length of 550 mm. The ends were covered by a mask ring.

[0058] In Table 1 the conditions for the thermal spraying of comparative Ni/W/Ta targets and such according to the present invention are listed.

TABLE-US-00001 TABLE 1 Comparative process: Process according to Thermal spraying the invention: Thermal conditions resulting spraying conditions in cracked and oval resulting in crack-free shaped tubes and in-spec round tubes Burner output  69 ± 1  59 ± 1 (kW) Powder supply 165 ± 5 150 ± 5 rate (g/min) Surface >45 18 < T < 35 temperature*) (controlled by intensive cooling) (C. °) Powder grain 45 to 90 45 to 90 size (μm) *)The surface of the target tube is measured by a calibrated IR thermometer during deposition of the target layer. The measurement is taken 50 cm behind the spray zone by traveling together with the spray gun.

[0059] In the following Table 2, the properties of the targets of Examples 1 and 3 and that of Comparative Examples 2 and 4 are given. The targets of Examples 1 and 3 were produced using the spraying process of the invention and the targets of Comparative Examples 2 and 4 were produced using the comparative process, with the conditions of both processes as shown in Table 1.

[0060] The quality of the produced targets was assessed based on whether or not macroscopic cracks occurred along the target length and/or whether or not the backing tube showed ovality, and the results are also shown in Table 2:

[0061] “good” means: no macroscopic crack along the target length, and no ovality of backing tube Dia.133.0>±0,5 mm.

[0062] “bad” means: at least one macroscopic crack along the target length and/or ovality of backing tube Dia.133.0>±0,5 mm

TABLE-US-00002 TABLE 2 Ni W Ta A.sub.Ni/(A.sub.W + (at. %) (at. %) (at. %) A.sub.Ta) I.sub.Ni I.sub.W I.sub.Ni/I.sub.W PIR Target 1 67.5 20.5 12 2.08 100 88.8 1.13 0.54 good CE2 67.5 20.5 12 2.08 78.6 100 0.79 0.38 Bad 3 75 25 0 3.00 100 67.9 1.47 0.49 good CE4 75 25 0 3.00 100 92.8 1.08 0.36 Bad