Abstract: Plasma deposition or etching apparatus is provided which comprises a plasma source located above and in axial relationship to a substrate process chamber. Surrounding the plasma source are an inner magnetic coil and an outer magnetic coil arranged in the same plane perpendicular to the axis of the plasma source and the substrate process chamber. Preferably, a first current is provided through the inner coil and a second current in a direction opposite to the direction of the first current is provided through the outer coil. The result is to advantageously shape the magnetic field in the process chamber to achieve extremely uniform processing, particularly when a unique diamond shaped pattern of gas feed lines is used wherein the diamond is arranged to be approximately tangent at four places to the outer circumference of the workpiece being processed in the apparatus.