Atomic layer deposition of ru nanocrystals with a tunable density and size for charge storage memory device application

We propose a deposition method capable of independently controlling the spatial density and average size of Ru nanocrystals by using both plasma-enhanced and thermal atomic layer deposition (ALD). Plasma-enhanced ALD is used to promote the nucleation of Ru nanocrystals, while thermal ALD is used to assist their growth. By the rigorous selection of each stage, we can demonstrate the formation of Ru nanocrystals with a density variation from 3.5× 1011 to 8.4× 1011 cm-2 and sizes from 2.2 to 5.1 nm, which is in the optimum density and size range of nanocrystal floating-gate memory application.