Computer simulation of plasma for plasma immersed ion implantation and deposition with bipolar pulses

In order to analyze the plasma behavior under the plasma immersion ion implantation and deposition (PIII&D) condition, a newly developed simulation software "PEGASUS" has been used. The spatial distributions of potential, ion and electron density were calculated for trench-shaped target immersed in Ar plasma (1 mTorr, 10(10) cm(-3)). The obtained time dependence of sheath length agreed with the analytical results based on Child-Langmuir theory. In the bipolar pulse PIII&D system, a positive- and a negative- pulse voltage are applied alternately to a target, instead of negative pulses used in the conventional PIII&D method. Using simulation, the following results were obtained; when a negative pulse voltage is applied to a target, a weak plasma is generated around the target. In contrast, when a positive pulse voltage is applied, a more intense plasma is generated under the same conditions. The results obtained by simulation of the behavior of ions and electrons near a trench-shaped target are presented. (C) 2003 Elsevier Science B.V. All rights reserved.