Preparation of thin films and nanosize powders by intense, pulsed ion beam evaporation

Efficient preparation of thin films has been achieved with a high-density ablation plasma produced by the interaction of an intense, pulsed ion beam with solid targets, a process called ion beam evaporation, having an instantaneous deposition rate of cm/s. In addition to standard front-side deposition, backside deposition, in which the substrate is placed on the reverse side of the holder, has been proposed to produce good quality thin films, though the deposition rate is one order of magnitude less than that in front-side deposition. By cooling of the ablation plasma, ultrafine nanosize ceramic powders, with a typical particle diameter of 10 nm, have been produced. The basic characteristics of the ablation plasma have been clarified by use of 1-D hydrodynamic equations with a simplified model involving primary ion-beam-driven expansion followed by adiabatic expansion into a vacuum. Analytical solutions will be given to define the plasma parameters.