Abstract: A system for sputtering uniformly thick films on a substrate is disclosed. The system includes a magnetron-sputtering cathode in a vacuum chamber, a gas inlet which injects processing gas at one end of the chamber, and a pump that pumps the processing gas from the other end of the chamber causing the process gas to flow across the substrate during processing. The magnetron-sputtering cathode includes a magnet array that is substantially circular. The magnets on the magnet array are positioned such that the gap between the magnets is smaller on the top of the array near the gas inlet than on the bottom of the array near the pump. The distribution of magnets creates a magnetic flux profile that results in more of the target being sputtered near the top of the cathode creating a thicker film at the top of the substrate.