Modification of Microstructure of Metal Films using High Power Pulsed Magnetron Sputtering

High power pulsed magnetron sputtering (HPPMS) is a variant of sputtering deposition method in that pulsed power is applied to the sputtering target with low repetition frequency and small duty ratio. It produces high density plasma intermittently which enables the ionization of sputtered atoms and the control of their energy and direction by introducing potential difference between the plasma and the substrate. We have proposed two HPPMS techniques which can control the plasma potential. One is to modify the target voltage waveform where the positive voltage is applied during the “pulse-off” period. The other is to use the triode configuration in which a positively-biased electrode is added. Positive plasma potential could be confirmed experimentally, and dense film structures and smooth surfaces could be obtained by these methods. It suggested that the ionized atoms impinged on the growing film surface with accelerated kinetic energy.