Variable cell size collimator

摘要

Sputtering apparatus and method suitable for forming a step coating on a workpiece. A workpiece is supported in a chamber, particles are emitted from a sputtering source, and the particles are passed through a collimating filter having a plurality of transmissive cells positioned between the sputtering source and the workpiece to limit the angles at which the particles can be deposited onto the workpiece. The collimating filter varies in height from a center portion to an outer portion while preferably maintaining a constant cell aspect ratio.