| CPC H01J 37/3491 (2013.01) [C23C 14/3407 (2013.01); H01J 37/3423 (2013.01); H01J 37/3426 (2013.01); H01J 37/3435 (2013.01); H01J 37/347 (2013.01); H01J 37/3432 (2013.01)] | 20 Claims |

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1. A sputtering target assembly comprising a sputtering target formed of a sputtering material having a non-planar sputtering surface at beginning of life (BOL), the non-planar sputtering surface having a circular shape and comprising:
a central axis region having a center axis, the central axis region including a cavity symmetrically disposed about the center axis and having a bottom surface, the bottom surface of the cavity being flat and having a first point on the center axis; and
a surrounding region disposed about the central axis region, the surrounding region comprising a top planar surface, a first recessed groove having a first bottom surface located below the top planar surface, a first sidewall and second sidewall extending upwards from the first bottom surface and a first depth, and a second recessed groove having a second bottom surface located below the top planar surface, a third sidewall and a fourth sidewall extending upwards from the second bottom surface and a second depth, wherein the first depth and the second depth are different, wherein the first point is below the top planar surface of the surrounding region, and the first point is below the first bottom surface and the second bottom surface;
wherein a distance from the top planar surface of the surrounding region to the first point is about 10 percent to about 30 percent of a total thickness of the sputtering target, and the cavity extends radially from the center axis a radial distance of from about 5 percent to about 40 percent relative to a total radius of the sputtering target.
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