Magnetron sputtering and its applications

The planar magnetron cathode was introduced in 1974. Magnetron sputtering has become the most important technology for the deposition of thin films when excellent performance is required. Today it is one of the key processes for manufacturing of innovative products like all kinds of discs for data storage and entertainment, flat displays, smart windows or thin film solar cells. The magnetron cathode combines the advantages of economic deposition even on large areas and the ability to coat very temperature sensitive plastic substrates. The long term stable deposition of highly insulating films on large areas at high growth rates, the stabilization of reactive processes in an unstable transition regime of the plasma discharge, and the improvement of target material utilization have been the main challenges to be solved during the past three decades. One of the main tasks in the near future will be the exploration of highly ionized plasmas and their benefits for even better film quality. High Power Impulse Magnetron Sputtering has already proven its potential in the field of tribological and optical coatings. In particular the optical industry needs dense films without any defects. New attempts to increase the sputter yield and thus film growth rate are "sputter yield amplification" or sputtering from hot targets. A novel process introduced as serial cosputtering provides yield amplification as well as improved stability for reactive deposition processes. The paper outlines milestones of the past 40 years and describes some of the new developments.