Time-averaged and time-resolved ion fluxes related to reactive HiPIMS deposition of Ti-Al-N films

The past decades in the development of plasma-based physical vapor deposition (PVD) techniques have meticulously focused on accessing innovative routes of controlled ion-bombardment during thin film growth. Within this context, high-power impulse magnetron sputtering (HiPIMS) – a technological advancement to drastically enhance the flux of ionised target species involved in conventional DC magnetron sputtering (DCMS) – is rendered particularly attractive for introducing novel means of influencing working gas- and metal-ions incident on substrate and growing film. HiPIMS utilises short (10 – 500 µs), yet highly energetic plasma discharges (up to several kW·cm^-2) at relatively low repetition rates (tens of Hertz to kilo-Hertz) to generate significantly increased plasma densities on the target surface, thus leading to an enhanced fraction of ions present in the film-forming vapor. The increased contribution of ions to thin film growth allows for an enhanced control over the energy delivered to the growing film, revealing new kinetic pathways of controlling the structure-property relationship. Consequently, complementary detailed plasma analysis in the time- and energy-domain has evolved into a vital extension for such ion-based PVD techniques through unfolding the correlation between deposition parameters and ion distributions (i.e., composition, energy, or temporal sequence) arriving on the substrate surface.