Influence of bias voltage rise time, pressure and magnetic field on the boundary layer time evolution of a thermal collisional magnetized plasma in plasma immersion ion implantation

The formation and temporal evolution of the plasma boundary layer in plasma immersion ion implantation is investigated in the presence of a magnetic field. It is assumed that the ions are thermalized. When a high-voltage pulse with a ramp function is applied to a target immersed in plasma, a positive space charge is formed and expanded around it. The rise time of the ramp function of the pulse voltage influences the formation and expansion of the plasma boundary layer near the target. The time evolution of the ion current density, ion kinetic energy and ion incident angle as well as the time evolution of the positive space charge and the boundary layer thickness are studied as a functions of the magnetic field, neutral gas pressure and rise time of the ramp function. Our findings show that the time dependency of the variables of the plasma boundary layer is more pronounced for a longer rise time.

Graphical Abstract

The governing equations, the simulation zone and temporal behavior of the incident angle of the ion for different magnetization parameters, neutral gas pressure and rise time