| AVS 64th International Symposium & Exhibition | |
| Advanced Surface Engineering Division | Thursday Sessions |
| Session SE+PS+SS-ThM |
| Session: | Plasma-assisted Surface Modification and Deposition Processes |
| Presenter: | Matjaz Panjan, Jozef Stefan Institute, Slovenia |
| Authors: | M. Panjan, Jozef Stefan Institute, Slovenia K. Tanaka, Lawrence Berkeley National Laboratory R. Franz, Lawrence Berkeley National Laboratory A. Anders, Lawrence Berkeley National Laboratory |
| Correspondent: | Click to Email |
The formation of dense plasma structures, called ionization zones or spokes, is now a well documented phenomenon in magnetron discharges [1,2]. Experiments and models suggest that these structures strongly influence the transport and the energy of electrons and ions [3,4]. Previously, we measured ion energy distribution functions in the plane of the magnetron by moving its target surface sideways with respect to the orifice of a combined mass spectrometer and energy analyzer (EQP300, Hiden Ltd.) [5]. The measurements showed asymmetric flux of ions in the plane of the target, which was attributed to the moving spokes. Here we report on the measurements of ion energy distribution functions for two different magnetron-EQP arrangements. In the first experimental arrangement, the orifice of EQP300 was directed in the plane of the magnetron and the magnetron was moved in the axial direction. In the second arrangement, the magnetron was rotated around its center for different polar angles while the distance between the target and the orifice was fixed. Measurements were performed in direct current magnetron sputtering (DCMS) using a 3” magnetron and niobium target. Ion energy distribution functions were measured for single and double charged argon and niobium ions. The first experiment showed that the largest flux of high-energy ions (i.e. ions above 10 eV) exists around 30 mm above the target. Overall, higher fluxes were observed in the E×B direction than in the -E×B direction. Polar measurements showed larger ion fluxes and higher ion energies near the target plane as compared to considerably lower fluxes and energies perpendicular to the target. The results of the measurements are discussed with respect to the plasma potential structure and associated electric field distribution of a rotating spoke, which we recently measured in DCMS discharge [6].
[1] A. Anders et al., J. Appl. Phys., 111 (2012) 053304
[2] M. Panjan et al., Plasma Sources Sci. Technol., 24 (2015) 065010
[3] R. Franz et al., Plasma Sources Sci. Technol., 25 (2016) 015022
[4] A. Anders, Appl. Phys. Lett., 105 (2014) 244104
[5] M. Panjan et al., Plasma Sources Sci. Technol., 23 (2014) 025007
[6] M. Panjan and A. Anders, J. Appl. Phys.121 063302 (2017)