A strategy for increased carbon ionization in magnetron sputtering discharges

A strategy that facilitates a substantial increase of carbon ionization in magnetron sputtering discharges is presented in this work. The strategy is based on increasing the electron temperature in a high power impulse magnetron sputtering discharge by using Ne as the sputtering gas. This allows for the generation of an energetic C+ ion population and a substantial increase in the C+ ion flux as compared to a conventional Ar-HiPIMS process. A direct consequence of the ionization enhancement is demonstrated by an increase in the mass density of the grown films up to 2.8 g/cm3; the density values achieved are substantially higher than those obtained from conventional magnetron sputtering methods.

► We achieve increased carbon ionization in high power impulse magnetron sputtering discharge. ► Increase in carbon ionization is achieved via the increase in electron temperature. ► The electron temperature is increased by utilizing a higher ionization energy sputtering gas (Ne) instead of conventionally used Ar. ► The Ne-HiPIMS discharge is characterized by energetic C+ ion population with three-fold increase in total number of C+ ions. ► The increased carbon ionization enables to synthesize carbon films with densities upto 2.8 g/cm3.