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 consisting of Ni, W and one or more further metal(s) X selected from the group of the Ta, Nb and Mo in an amount of from 3 to 20 atom %, wherein the target 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 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 one or more further metal X is Ta.

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

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

Description

EXAMPLES

(1) 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.

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

(3) 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.

(4) 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.

(5) 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:

(6) “good” means: no macroscopic crack along the target length, and no ovality of backing tube Dia.133.0>±0.5 mm.

(7) “bad” means: at least one macroscopic crack along the target length and/or ovality of backing tube Dia.133.0>±0.5 mm

(8) 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