Recent progress in thin film processing by magnetron sputtering with plasma diagnostics

The precise control of the structure and related properties becomes crucial for sophisticated applications of thin films deposited by magnetron sputtering in emerging industries including the flat panel display, digital electronics and nano- and bio-industries. The film structure is closely related to the total energy delivered to the substrate surface for nucleation and growth during all kinds of thin film processes, including magnetron sputtering. Therefore, the energy delivered to the surface for nucleation and growth during magnetron sputtering should be measured and analysed by integrated diagnostics of the plasma parameters which are closely associated with the process parameters and other external process conditions. This paper reviews the background of thin film nucleation and growth, the status of magnetron sputtering technology and the progress of plasma diagnostics for plasma processing. The evolution of the microstructure during magnetron sputtering is then discussed with respect to the change in the process variables in terms of the plasma parameters along with empirical data of the integrated plasma diagnostics for various magnetron sputtering conditions with conventional dc, pulsed dc and high power pulsed dc sputtering modes. Among the major energy terms to be discussed are the temperature change in the top surface region and the energies of ions and neutral species.