In a broad beam ion source for industrial applications such as sputter deposition, ions produced by DC or RF electrical gas discharge, are accelerated into many beamlets by means of an electrostatic extraction system. The accelerating stage is composed of two multi aperture grids (screen grid and extraction grid). The confluence of individual beamlets results in the formation of an ion beam drifts toward sputter target. The control of ion beam’s intrinsic divergence induced by space charge effect is essential to eliminate undesirable material sputtering.
In this paper, the drift of an Ar$^+$ ion beam is simulated via the CST particle studio software by considering the space charge effect. We investigate the effect of grid’s geometry on the properties of ion beam. We show that the space charge induced divergence of ion beam is significantly influenced by several geometrical factors such as the diameter of apertures, the thickness of grids and the distance between grids.