Angular distribution of titanium ions and neutrals in high-power impulse magnetron sputtering discharges

The angular dependence of the deposition rates due to ions and neutrals in high-power impulse magnetron sputtering (HiPIMS) discharges with a titanium target were determined experimentally using a magnetically shielded and charge-selective quartz crystal microbalance (or ionmeter). These rates have been established as a function of the argon working gas pressure, the peak discharge current density, and the pulse length. For all explored cases, the total deposition rate exhibits a heart-shaped profile and the ionized flux fraction peaks on the discharge axis normal to the cathode target surface. This heart-shaped pattern is found to be amplified at increasing current densities and reduced at increased working gas pressures. Furthermore, it is confirmed that a low working gas pressure is beneficial for achieving high deposition rates and high ionized flux fractions in HiPIMS operation.

Automated summary

The angular dependence of deposition rates in HiPIMS with a titanium target has been experimentally determined. The rates depend on the argon gas pressure, discharge current density, and pulse length. The total deposition rate exhibits a heart-shaped profile, with the peak ionized flux fraction on the discharge axis. This pattern is amplified at higher current densities and reduced at higher gas pressures. Low gas pressure is confirmed to be beneficial for achieving high deposition rates and high ionized flux fractions in HiPIMS operation.