Sputtering target, sputtering target-backing plate assembly and deposition system
View Patent ↗Provided is a tabular sputtering target on which an erosion portion and a non-erosion portion are formed, and the surface area thereof exceeds 100% but is less than 125% of the surface area when the target is assumed to be planar. Also provided is a tabular sputtering target on which an erosion portion and a non-erosion portion are formed comprising one or more concave portions on the target surface region, and the surface area thereof exceeds 100% but is less than 125% of the surface area when the target is assumed to be planar. An inexpensive, small-capacity power supply unit can be used by minimizing the electrical variations in the sputtering circuit as much as possible throughout the lifespan of the target through self sputtering or high power sputtering.
1. A sputtering target and backing plate assembly, comprising:
a target having a tabular shape defined by a sputtering face exposed to sputtering, a rear face, and an annular side face, the sputtering face containing flat portions, a portion suffering erosion during sputtering, and an annular inclined face formed along a peripheral edge of the sputtering face, the rear face being parallel to the flat portions of the sputtering face, and the annular side face being perpendicular to the rear face, the target consisting of Cu, Ta, or Ti; and
a backing plate that mates with and is secured to said rear face of said target;
wherein said sputtering face, as prepared to be used in sputtering and before any sputtering is commenced, includes one or more annular surface irregularities each having a concave cross-sectional shape;
said annular surface irregularities being formed by machining at a location corresponding to said portion suffering erosion during sputtering; and
said sputtering face with said annular surface irregularities having a surface area being greater than 100% and less than 125% of the surface area of the sputtering face when flat;
wherein the backing plate has a face having a recess in which the sputtering target is received and secured to form the sputtering target and backing plate assembly; and
wherein said recess of the backing plate is of a first thickness at a location underlying a part of the sputtering target containing said annular surface irregularities and is of a second thickness at a location underlying a remainder of the target including a central part thereof, said first thickness being larger than said second thickness, and the rear face of the target having a shape that mates a front surface of the backing plate.
2. A sputtering target and backing plate assembly according to claim 1 , wherein each of said annular surface irregularities of the sputtering face, as prepared by machining, is an annular groove having a V cross-sectional shape.
3. A sputtering target and backing plate assembly according to claim 1 , wherein the surface area of the sputtering face machined with said annular surface irregularities is 105% to less than 125% of the surface area of the sputtering face when flat.