Three Dimensional Model for Anomalous Target Erosion in Magnetron Sputtering

摘要

A parallelized three dimensional simulation environment for low pressure/low temperature plasma discharges has been implemented at Fraunhofer IST. Based on this tool, plasma discharges of rectangular planar magnetrons were simulated, focusing on the cause for anomalous target erosion known as cross-corner effect.The simulation results pointed out a strong correlation between the electron density distribution and the perpendicular magnetic field geometry across the target surface i.e. The magnetic confinement. According to this correlation an explanation model for the cross-corner effect has been developed which is related to the electron drift current and the spatial geometry of the magnetic confinement.It was assumed that the cross-corner effect is related to an angular deviation of the magnetic confinement at the end section of conventional sputter magnetrons. According to this assumption the layout of a conventional sputter magnetron was adjusted to counteract the angular deviation. Based on our simulations, it could be shown, that these adjustments significantly reduce the cross-corner effect.