The achievement of perfectly vertical sidewalls with minimum line-edge roughening is one of the most challenging problems in plasma etching of nanometer scale features. A number of phenomena were found to produce undesirable profiles, including reflection of ions on sidewalls, poor lithography, poor selectivity to resist, accumulation of charges, and line-of-sight redeposition of sputtered species. This work examines the influence of indirect redeposition resulting from the interaction of sputtered particles with the plasma phase, a relatively unexplored, yet very important aspect in plasma etching. The degree of indirect redeposition was first measured during etching of Platinum (Pt), Barium-Strontium-Titanate (BST), and Photo-Resist (PR) in a high-density argon plasma. While PR exhibits a redeposition-free behavior, the degree of indirect redeposition of Pt and BST increased from 10 to 90% as the pressure increased from 0.5 to 10 mTorr. The influence of redeposition on the space and time evolution of feature profiles was also examined through simulations based on a cellular approach using Monte-Carlo techniques. The model takes into account particles reflection, angular dependent etch-yield, number density and angular distribution for neutrals and ions. Overall, the simulator successfully reproduced experimental profiles sputter-etched in Pt, in particular V-shaped profiles. From a comparison between experimental and simulated profiles at very low pressure, the Pt/resist sticking probability was estimated to be 0.1 and the angular spread of the sputtered atom distribution by low-energy ions was predicted to be about ±50°. It was further found that indirect redeposition becomes crucial at higher pressure for explaining the amount of redeposited matter.