Area-selective deposition (ASD) is a possible enabler for the fabrication of various future semiconductor devices. However, it remains challenging to characterize and optimize ASD processes in patterns with nanoscale dimensions, as required for semiconductor device applications. Therefore, we study Ru ASD on different types of nanopatterns on 300 mm-wafers and assess the role of the pattern geometry and density on selectivity. As selectivity is often improved by means of passivation-deposition-etch cycles, we investigate an ASD cycle consisting of passivation by (N,N-dimethylamino)trimethylsilane, deposition by (ethylbenzyl)(1-ethyl-1,4-cyclohexadienyl)Ru/O2 atomic layer deposition (ALD) and an O/Cl plasma etch. On line-space patterns with a 32 nm critical dimension, the passivation-deposition-etch cycle yields a lower defectivity level than the passivation-deposition approach for a given Ru ASD thickness. The comparison of Ru ASD on line-space and hole nanopatterns reveals the pattern-dependent selectivity, that is explained by accumulation of Ru nanoparticles at pattern edges. 300 mm-wafer uniformity is also investigated and related to reactor design. The investigation of ASD on nanopatterned 300 mm-wafers is enabled by ASD-specific developments of X-ray photoelectron spectroscopy, optical critical dimension scatterometry, and scanning electron microscopy. This research highlights the possibilities and challenges in developing ASD processes in an industrial setting.