Plasma dynamic in chromium and titanium HIPIMS discharges

Using a cylindrical Langmuir probe, time-resolved measurements of plasma parameters near the substrate were carried out in a high power impulse magnetron sputtering (HIPIMS) discharge. Two different target materials (Ti and Cr) were used and a magnetron was operated at a pressure of 0.28 and 2.66 Pa, frequency of 100 Hz, pulse duration of 70 mu s and a duty cycle of 0.7%. The results show that a high density plasma (n similar to (0.1-0.8) x 10(18) m(-3)) is generated near the substrate in the studied pressure range. A strong dependence of the plasma density on the target material is observed at the same value of the discharge current. This phenomenon is thought to be due to the effect of the sputtering yield of the target material on the ionization and transport processes in the discharge. The plasma dynamic is studied through the temporal evolution of the electron energy distribution function.