Electron-optical investigations on cold cathode electron beam sources for high-rate PVD

Electron Beams (EB) are known to be powerful and versatile tools for evaporation of various kinds of materials. At the other hand, conventional high-power electron beam sources based upon thermionic emitters arc expensive and therefore in many thin film processes not applicable because of economic considerations. Electron beam sources with cold cathodes stimulated by high-voltage glow discharges (HVGD) have recently attracted enhanced interest at FEP mainly because of their prospects as economic beam sources for physical vapor deposition (PVD). Particle-in-cell simulations (PIC) of the high-voltage glow discharge and of the beam formation in a simple geometry have been carried out to study the effects of the electrodes' geometry and of some discharge parameters on the electron-optical characteristics. To create a powerful, cost efficient and low-maintenance EB evaporator system for industrial PVD processes, a thermally isolated ("hot") crucible with an integrated beam bending system and a specially shaped vapor aperture has been developed and tested together with a cold-cathode EB gun.