Influence of sample placement on the dose uniformity in plasma immersion ion implantation of industrial ball bearings

Plasma immersion ion implantation (PIII) is an effective technique to enhance the surface properties of industrial components possessing an irregular shape. However, it is difficult to achieve uniform implantation along the groove surface of a ball bearing. In this work, we focus on the PIII treatment of the arc surface of an industrial ball bearing. Three practical sample placement configurations are investigated: I) direct placement on the sample stage platen, II) placement on a copper extension with the same diameter as the bearing race, III) placement on a copper plate erected on the sample stage by means of a small metal rod. Using theoretical simulation, the implant dose uniformity along the groove surface is determined for the three orientations. Our results reveal that configuration III) yields the largest implant dose along the groove surface and the dose uniformity is worse in configuration I). Hence, in order to improve the lateral dose uniformity along the race surface, the bearing should be elevated from the sample.