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The high power impulse magnetron sputtering (HIPIMS) is a promising addition to existing physical vapor deposition (PVD) techniques. It provides high plasma densities and high fractional ionization of the sputtered material. The sputtered material is thus controllable with respect to energy and direction as it arrives as ions to the growth surface. Here, the ionization mechanism and the temporal behavior of the plasma parameters in a high power impulse magnetron sputtering discharge are investigated using a simple time dependent global (volume averaged) model. The ionized metal fraction and the ionized flux fraction are very high and the integrated ionized flux fraction is 0.89 for aluminum. During the pulse on period electron impact ionization is the most effective mechanism in creating metal ions while charge exchange becomes the dominant mechanism in creating metal ions after the pulse is off. |