Time-domain and energetic bombardment effects on the nucleation and post-nucleation characteristics during none-quilibrium film synthesis
(English)Manuscript (preprint) (Other academic)
Pulsed vapor fluxes are employed to deposit metallic (Ag) films on amorphous (SiO2) substrates. These fluxes are generated by employing the ultra-fast plasma based method high power impulse magnetron sputtering (HiPIMS) in a way that facilitates accurate control over the temporal profile of the vapor flux and the energy transferred from the vapor to the growing film. In situ monitoring of the film growth unravels the effect of time domain of the deposition flux and energetic bombardment on the nucleation and post-nucleation features of the films. It is found that the film thickness when the film become continuous exhibits a dependence on the pulsing frequency for material pulses with a constant average flux and energy of the depositing species and a dependence on the instantaneous flux and energy of the deposited species for a constant pulsing frequency. These findings provide data that can be used to facilitate meaningful correlation with theoretical descriptions of growth processes where energetic bombardment and modulation of the vapor flux are key factors. Moreover, characteristic times for adatom diffusion and island coalescence are estimated and it is found that there are synthesis conditions at which these times are comparable with the time scale of the modulation of the deposition flux. The interplay between these time scales can be used as a tool to determine characteristic surface diffusion and island coalescence parameters by studying nucleation and post-nucleation film morphology experimentally.
IdentifiersURN: urn:nbn:se:liu:diva-86470OAI: oai:DiVA.org:liu-86470DiVA: diva2:577760