Transport and deposition processes of sputtered particles in rf-microwave hybrid sputtering discharges

Transport and deposition processes of sputtered particles from a (Ba, Sr) TiO 3 target have been investigated in rf-microwave hybrid discharges with Ar/O 2 . Deposition experiments were made over the gas pressure range of 0.5–10 mTorr using trenched substrates. Moreover, numerical simulations were carried out to reveal the effects of gas-phase scattering and surface re-emission of particles on their trajectories and the resulting deposition profiles in trenches. In the experiments, the step coverages of narrower trenches with aspect ratios above unity were found to be improved with decreasing pressure; such deposition behavior was predicted by the simulations, and was ascribed to the higher directionality of depositing fluxes onto the substrate at lower pressures.