Simulation of temperature distribution on a spherical target during plasma immersion ion implantation

Ion implantation has been shown to be an effective surface modification technique without the sacrificing the bulk properties. The modification results are, however, influenced not only by the implantation voltage, incident dose, but also the treatment temperature, particularly in elevated temperature ion implantation into metals with lower temper temperature. During the treatment, both the sample temperature and its history contribute to the final surface properties. In this paper, we investigate the temperature distribution on a spherical target during plasma immersion ion implantation (PIII) using numerical simulation. The majority of the heat input into the target is shown to originate from the energetic ions accelerated by plasma sheath. Our simulation results also demonstrate that the implantation voltage, pulsing frequency, pulse duration and plasma density exert different influence on the temperature rising rate in addition to the equilibrium temperature. The influence of the target size is also simulated, since it critically affects the heating and cooling characteristics of the process. Our model is important to the understanding of the local temperature variation and heating rate of both planar and non-planar samples during plasma immersion ion implantation.