[Granted] A plasma processing apparatus includes a process chamber, a platen positioned in the process chamber for supporting a workpiece, a source configured to generate a plasma in the process chamber having a plasma sheath adjacent to the front surface of the workpiece, and an insulating modifier. The insulating modifier has a gap, and a gap plane, where the gap plane is defined by portions of the insulating modifier closest to the sheath and proximate the gap. A gap angle is defined as the angle between the gap plane and a plane defined by the front surface of the workpiece. Additionally, a method of having ions strike a workpiece is disclosed, where the range of incident angles of the ions striking the workpiece includes a center angle and an angular distribution, and where the use of the insulating modifier creates a center angle that is not perpendicular to the workpiece.