High power pulsed magnetron sputtering (HPPMS) is an emerging technology that has gained substantial interest among academics and industrials alike. HPPMS, also known as HIPIMS (high power impulse ...

High power pulsed magnetron sputtering: A review on scientific and engineering state of the art

The high power impulse magnetron sputtering (HiPIMS) discharge is a recent addition to plasma based sputtering technology. In HiPIMS, high power is applied to the magnetron target in unipolar pulse ...

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High power impulse magnetron sputtering discharge

We demonstrate the evolution of the electron, energy distribution and the plasma parameters in a high-density plasma in a pulsed magnetron discharge. The high-density plasma is created by applying ...

Spatial and temporal behavior of the plasma parameters in a pulsed magnetron discharge

The article reports on flexible hard nanocomposite coatings prepared by magnetron sputtering. It is shown that the flexible hard nanocomposite coatings (i) represent a new class of coatings which are simultaneously hard, tough and resistant to cracking, (ii) exhibit high values of the hardness H and effective Young's modulus E* ratio H/E* ≥ 0.1, elastic recovery We ≥ 60%, compressive macrostress σ < 0 and dense, void-free microstructures, and (iii) are formed in the zone T of the Thornton's Structural Zone Model (SZM); here E* = E/(1 − ν2), E is the Young's modulus and ν is the Poisson's ratio. The magnetron sputtering, which is a very powerful process used in the preparation of nanocomposite coatings, is described in detail. The basic principles of the formation of the flexible hard coatings are also described in detail. It is shown that the key parameters which determine the formation of these coatings are (1) the energy Ep = Eca + Ebi delivered to the growing coating by condensing atoms (Eca) and bombarding ions (Ebi) (the non-equilibrium heating), (2) the substrate heating controlled by the substrate temperature Ts (the equilibrium heating) and (3) the melting temperature Tm of the coating material. The flexible hard coatings have a huge application potential. Four examples of flexible coatings are given: (1) flexible protective coatings, (2) flexible functional coatings, (3) flexible over-layer preventing cracking of brittle coating and (4) flexible multilayer coating. Also, the principle of low-temperature sputtering of flexible nanocomposite coatings is described in detail. Finally, trends for future development of these nanocomposite coatings with unique properties are given.

Flexible hard nanocomposite coatings

The physical and chemical aspects of plasma–surface interaction in high-power impulse magnetron sputtering (HiPIMS) discharges are overviewed. The data obtained by various plasma diagnostic methods representing the important sputtering discharge regions, namely the cathode vicinity, plasma bulk, and substrate vicinity, are reported. After a detailed introduction to the problem and description of the plasma characterization methods suitable for pulsed magnetron discharge analysis, an overview of the recent plasma diagnostics achievements in both non-reactive and reactive HiPIMS discharges is presented. Finally, the conclusions and perspectives suggesting possible directions and research strategies for increasing our knowledge in this domain are given.

http://iopscience.iop.org/article/10.1088/0022-3727/47/22/224001/pdf

Plasma diagnostics for understanding the plasma?surface interaction in HiPIMS discharges: a review

This article analyzes a pulsed magnetron discharge. Main attention is devoted to the specific behavior of the pulsed discharge. The time development of pulsed discharge is composed of three regimes of operation: (1) plasma buildup, (2) stationary plasma, and (3) decaying plasma when the pulse power is off. The duration of individual regimes strongly depends on the pulse length t1, the repetition frequency fr of pulses, the power delivered into the discharge, and the operating pressure. The proportion of duration of the regime of plasma buildup to the regime of stationary plasma in the pulse dramatically influences the I–V characteristics of the pulsed discharge and the deposition rate of sputtered films. The I–V characteristics of an unbalanced round planar magnetron with a Cu target 100 mm in diameter are shown. The deposition rate of Cu films sputtered with the pulsed magnetron is also given.

Pulsed dc magnetron discharge for high-rate sputtering of thin films

Cavity ring-down spectroscopy combined with laser induced fluorescence was applied during a high-power impulse magnetron sputtering of Ti target to determine the time evolutions and spatial distributions of Ti atom and ion densities of levels belonging to the ground state multiplets (GSM) near the sputtered target. From these densities, an estimate of the time evolution and spatial distribution of the ionization degree near the target was calculated. It was found that the densities (number of particles per unit volume) of levels in GSM of Ti atom and ion increases with their level energies and the highest levels in GSMs show an inversion in their populations (the density of level divided by its statistical weight) during a voltage pulse. The population inversion (a higher population of levels with a higher energy than those with lower ones) is distinct for the highest level in GSM of Ti+ ion and it persists even at 40 μs after the voltage pulse end. The sum of ground state level densities reaches values up to 8.3 × 1011 cm−3 for Ti+ ions above the target racetrack and up to 4.8 × 1011 cm−3 for Ti atoms above the target center for the regime with the peak power density of 498 W cm−2. A frequent ionization of Ti atoms above the target racetrack is manifested by distinct drops in the Ti atom spatial distribution. This leads to a very high ionization degree up to 94% at the racetrack position and the ionization degree stays also high 40 μs after the voltage pulse termination.

On density distribution of Ti atom and ion ground states near the target in HiPIMS discharge using cavity ring-down spectroscopy and laser induced fluorescence

Tomáš Tölg

Papers

Pulsed dc magnetron discharge for high-rate sputtering of thin films

On density distribution of Ti atom and ion ground states near the target in HiPIMS discharge using cavity ring-down spectroscopy and laser induced fluorescence