Continuous superposition of high power pulses and radio frequency power on a single magnetron target

High Power Impulse Magnetron Sputtering (HiPIMS) offers significant advantages over established sputtering techniques such as DC, MF, or RF sputtering. Thin films deposited with HiPIMS exhibit improved properties but often suffer from low deposition rates. In addition, reactive HiPIMS processes tend to arc. Superposition of different plasma excitations may help to overcome these limitations. We investigated the superposition of HiPIMS and RF on a single magnetron and studied voltage–current characteristics as well as the influence of pressure on process stability and cathode voltage for the reactive and non-reactive deposition of Aluminium in Ar/O2 discharge. We found that superimposing RF onto HiPIMS allows for stable operation at lower pressures and reduces arcing. Notably, the effect of the superimposed RF on peak current differs by mode: in reactive sputtering, the HiPIMS peak current is increased, while in non-reactive mode, the peak current is decreased. This is attributed to the different secondary electron emission in non-reactive and reactive mode.