Physical Analysis of Plasma Features in High Power Impulse Magnetron Sputtering（HiPIMS）Discharges

As a promising physical vapor deposition(PVD)technique,high power impulse magnetron sputtering(HiPIMS)attracts widespread attention both in academic and industrial fields. The energy density with a low average value but high peak value at the target featured for HiPIMS avoids the issue of target melting by overheating. In addition,the unique discharge characteristic endows HiPIMS with high plasma density and ionization fraction of the sputtered vapor,which enables better control of energy and motion of the deposition species. Consequently,multifunctional thin films with high quality could be deposited and applied in multiple industrial applications.The HiPIMS discharge accordingly has been successfully introduced into a variety of industrial fields. In this review,the power characteristics and pulse generator of HiPIMS have been addressed. The pulse parameters,including discharge voltage,current,and pulse length,have been systematically discussed. Finally,the physics and properties of four different discharge regions(i.e.,cathode target and sheath region,ionization region,bulk plasma region,as well as anode plasma and substrate region)involved in the process of HiPIMS discharge have been reviewed in-depth. This work is beneficial to deepen the physical understanding of HiPIMS and further broaden its practical applications.