Numerical simulation of plasma immersion ion implantation of a finite-length cylindrical bore with auxiliary electrode by two-dimensional fluid model

Plasma immersion ion implantation of the interior surface of an infinite length cylindrical bore with an auxiliary electrode has been studied in some detail. The geometry considered so far is one dimensional with all variables as functions of the radial direction in cylindrical coordinates. If we consider a cylindrical bore with finite length, then the PIII process becomes a two-dimensional case that is a totally different class of problem. All the variables will depend on the radial and longitudinal directions in cylindrical coordinate. In this article, plasma immersion ion implantation (PIII) of the inner surface of a finite length cylindrical bore with a coaxial, grounded auxiliary electrode is modeled using a two-dimensional fluid simulation. A thin ring shape cylindrical bore is used in our simulation. It is found that the sheath structure resulting from the auxiliary electrode focuses ions from both inside and outside the bore onto the inner surface. To provide uniform implantation of the inner surface, it is recommended that the implantation process ends after the initial charge of ions is emptied from the bore.