Plasma Characteristics On Hybrid High Power Impulse Magnetron Sputtering Discharge

Hybrid high power impulse magnetron sputtering (hybrid HIPIMS) is a new-generationHIPIMS technique with a pulse and direct current power supply paralleled connection operation.The discharge and plasma characteristics are of vital importance for hybrid HIPIMS filmdeposition. Therefore, the influence of pulse voltage (400~800V), pulse width (50~400μs) anddirect current (0.0~4.0A) supplied by the direct current power is investigated on hybrid HIPIMSTi, Cr discharge characteristics, plasma parameters (plasma potential, electron temperature andelectron density) and Ti film properties in an Ar atmosphere. The results show that the absolutevalue of target voltage, target current, substrate current, electron density increases while plasmapotential, electron temperaturedecreases with increasing the pulse voltage during the pulse turn-on.However, plasma potential, electron temperature increases and electron density decreases afterabout600V,700V for Ti, Cr respectively. Although the target voltage, target current, substratecurrent is barely varied, the waveforms of them are affected strongly with the pulse width from50to400μs. The electron density is found to dramatically increase with the pulse width from150to250μs, which indicates a high sputtered titanium ionization rate in this stage. As the direct currentincreases from0~4.0A, the target voltage is affected little, whereas the target current decreasesduring the pulse turn-on. The plasma parameters have been significantly influenced by the directcurrent. We find the target current，substrate current, plasma potential and electron temperatureofCr are lower than Ti at the same conditions, but the electron density is higher. Moreover, throughoptimizing the influence ofpulse voltage, pulse width and direct current on hybrid HIPIMS Tifilmdeposition, we also obtain a high quality Ti film with average roughness0.9nm and hardness10.20GPa at the pulse voltage600V, pulse width200μs，direct current1.0A and substrate bias-150V. The samples are selected for comparison with that prepared by conventional direct currentmagnetron sputtering (DCMS) at the same average target power. The results demonstrate that Tifilms using hybrid HIPIMS have a close deposition rate and a superior quality and performance tothose prepared using DCMS especiallyat the low target power.