Tantalum sputtering target, and production method therefor
Provided is a tantalum sputtering target, which includes an area ratio of crystal grains of which a {111} plane is oriented in a direction normal to a rolling surface (ND) is 35% or more when the ND, which is a cross section orthogonal to a sputtering surface of a target, is observed via Electron Backscatter Diffraction Pattern method. The object of the present invention is to provide a tantalum sputtering target in which a sputtered material can be uniformly deposited on a wafer surface under high-power sputtering conditions by increasing the straightness of the sputtered material. By using this kind of tantalum target for sputter-deposition, it is possible to improve the film thickness uniformity and the throughput of deposition even for fine wiring.
1. A tantalum sputtering target comprising, wherein orientations of crystal grains constituting the tantalum sputtering target in relation to a direction normal, ND, to a sputtering surface of the tantalum sputtering target observed via an electron backscatter diffraction pattern method along a cross section of the tantalum sputtering target orthogonal to the sputtering surface of the tantalum sputtering target are such that:
a total area of areas of the crystal grains having an orientation such that a {111} plane thereof is oriented in the ND direction observed in the cross section of the tantalum sputtering target has an area ratio of 35% or more relative to a total area of the cross section of the tantalum sputtering target observed; and
A {111} /A {100} is 2.0 or more, where A {111} represents an area ratio of the total area of areas of crystal grains having a {111} plane oriented in the ND direction observed in the cross section of the tantalum sputtering target relative to the total area of the cross section of the tantalum sputtering target observed and A {100} represents an area ratio of a total area of areas of crystal grains having a {100} plane oriented in the ND direction observed in the cross section of the tantalum sputtering target relative to a total area of the cross section of the tantalum sputtering target observed.
2. The tantalum sputtering target according to claim 1 , wherein A {111} is 36.7% to 50.5%.
3. The tantalum sputtering target according to claim 2 , wherein A {100} is 7.5% to 18.3%.
4. The tantalum sputtering target according to claim 1 , wherein A {111} /A {100} is 2.01 to 6.73.
5. The tantalum sputtering target according to claim 1 , wherein A {111} is 48.5% to 50.5%.
6. The tantalum sputtering target according to claim 5 , wherein A {100} is 7.5% to 8.6%.
7. The tantalum sputtering target according to claim 1 , wherein A {111} /A {100} is 5.64 to 6.73.