Concave sputtering apparatus

摘要

A sputtering cathode comprising a concave surface for receiving and supporting a sputtering target having a substantially conformal concave shape. The cathode is cooled via passage of a suitable coolant through passageways within the cathode. The target is constrained to the cathode along the target periphery. The target expands thermally during sputtering, but being constrained laterally the target is forced into intimate contact with the cooled concave cathode surface. The target is thus cooled over its entire surface, resulting in predictable, uniform erosion rates and target wear, whereas prior art planar cathodes are known to suffer from undesirable buckling of the target away from the cathode due to thermal expansion of the target in use. Cathodes and targets in accordance with the invention are non-planar and preferably are either spherically or cylindrically concave.