Abstract
The present paper is focused on time-resolved diagnostics of the simultaneous combination of dual mid-frequency and dual-high power impulse magnetron sputtering discharges (so-called hybrid-dual-HiPIMS systems). Combined systems are operated with the following parameters - dual-high power impulse magnetron sputtering (f(H) = 100 Hz, duty cycle 1%) and dual mid-frequency discharge (f(M) = 94 kHz, duty cycle 30%) - running simultaneously with two magnetron guns.
The magnetrons in dual configuration are electrically confined, i.e. electrodes are alternately operated as an anode-cathode (and vice versa) during the sputtering. The dual MF discharge causes a pre-ionization effect which is an important feature because of: (i) a significant reduction of the working pressure by more than one order of magnitude, (ii) an increase of electron and ion energy, and (iii) an increase of the deposition rate.
It was found that the ion velocity distribution function (IVDF) during HiPIMS pulses reaches a maximum of about 15-20 eV whereby the dual MF discharge reaches about 0.5-1.5 eV. The time-resolved IVDF measurements revealed that ions with high energy generated at the cathode arrive at the substrate position about 25-30 mu s after the HiPIMS pulse ignition.
The effect of the hybrid system is illustrated on the deposition of Ti-Cu films. The crystallographic phase and properties of the deposited films are strongly influenced by the energy of incoming particles and by reduced pressure in the chamber.