Embodiments of the disclosure include a fixed position mask for workpiece edge treatment. In some embodiments, an apparatus includes a roplat having a rotatable assembly, and a platen coupled to the rotatable assembly, wherein the platen is configured to hold a workpiece. The apparatus further includes a bracket affixed to the rotatable assembly, and a mask directly coupled to the bracket, wherein the mask is positioned adjacent the workpiece. The mask covers an inner portion of the platen and the workpiece, leaving just an outer circumferential edge of the workpiece exposed to an ion treatment. In some embodiments, the platen is permitted to rotate relative to the bracket during an ion treatment. In some embodiments, the mask includes a solid plate section devoid of any openings, and a mounting portion extending from the plate section, wherein the mounting portion is directly coupled to an extension arm of the bracket.