Particle-in-cell simulation of plasma immersion ion implantation (PIII) of industrial gears

Summary form only given. Plasma immersion ion implantation (PIII) has emulates conventional beam-line ion implantation in that the implantation time is independent of the sample size and large industrial components of an irregular shape can be treated relatively easily due to its non-line-of-sight characteristic. For example, due to the non-planar and periodic structure of industrial gears, conventional deposition and beam-line treatment techniques are not easily implemented. In addition, as they are used in space, typically as a component in a satellite, conventional coatings may not function desirably either, and PIII is the ideal technique in this case. In this work, we employ a theoretical model to investigate the PIII process of this important industrial component. To simulate implantation into the three-dimensional structure of a commercial gear, we work in cylindrical coordinates. Due to the periodic structure of the saw-teeth, we only need to simulate the volume of one tooth. 2D simulation along the (r-0) plane is carried out by the particle-in-cell (PIC) method. The incident dose and impact angle along the surface of the tooth are derived and our results indicate that a long implantation pulse will implant more ions at the bottom of the tooth at normal angle since the momentum of the incoming ions accelerated at the middle and end period of the pulse will overcome the attractive force from the sidewall of the tooth. Therefore, shorter pulse duration will implant the whole surface of the tooth more uniformly. We will also provide an estimation on the preferred pulse duration for different tooth dimensions.