High power impulse magnetron sputtering: Current-voltage-timecharacteristics indicate the onset of sustained self-sputtering
The commonly used current-voltage characteristics are foundinadequate for describing the pulsed nature of the high power impulsemagnetron sputtering (HIPIMS) discharge, rather, the description needs tobe expanded to current-voltage-time characteristics for each initial gaspressure. Using different target materials (Cu, Ti, Nb, C, W, Al, Cr) anda pulsed constant-voltage supply it is shown that the HIPIMS dischargestypically exhibit an initial pressure dependent current peak followed bya second phase that is power and material dependent. This suggests thatthe initial phase of a HIPIMS discharge pulse is dominated by gas ionswhereas the later phase has a strong contribution from self-sputtering.For some materials the discharge switches into a mode of sustainedself-sputtering. The very large differences between materials cannot beascribed to the different sputter yields but they indicate thatgeneration and trapping ofsecondary electrons plays a major role forcurrent-voltage-time characteristics. In particular, it is argued thatthe sustained self-sputtering phase is associated with thegeneration ofmultiply charged ions because only they can cause potential emission ofsecondary electrons whereas the yield caused by singly charged metal ionsis negligibly small.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE. Assistant Secretary for Energy Efficiency andRenewable Building Technologies; EPSRC grant EP/D049202/1 and theWenner-Gren Foundatio n
- DOE Contract Number:
- DE-AC02-05CH11231
- OSTI ID:
- 928240
- Report Number(s):
- LBNL-63685; JAPIAU; R&D Project: 677622; BnR: BT0304030; TRN: US0804307
- Journal Information:
- Journal of Applied Physics, Vol. 102; Related Information: Journal Publication Date: 12/04/2007; ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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