Studying Target Erosion in Planar Sputtering Magnetrons Using a Discrete Model for Energetic Electrons
A discrete model for the prediction of relative ion bombardment flux and target erosion in planar sputtering magnetrons is implemented in COMSOL Multiphysics®. Planar magnetrons are used within physical vapor deposition (PVD) processes to form thin film depositions on various types of substrates. The presented model portrays trajectories of energetic electrons within low pressure direct current (DC) gas discharges subjected to forces from the involved static electromagnetic fields and undergoing collisions with neutrals. Relative distributions of ion bombardment flux and target erosion are obtained by summation and projection of ionization collisions onto the target surface. An iterative scheme based on a series of consecutive transient analyses is adopted. The model can resolve typical erosion profiles and characteristic features such as the cross corner effect.