Selective silicon nanoparticle growth on high-density arrays of silicon nitride

Selective silicon nanoparticle deposition from disilane on ∼17 nm diameter Si3N4 features defined through a 15-nm-thick SiO2 masking layer was studied using hot wire chemical vapor deposition between 900 and 1025 K, and chemical vapor deposition between 900 and 975 K. Thin film poly(styrene-b-methyl methacrylate) diblock copolymer was used to generate cylinders with a density of 6×1010 cm−2 that served as the patterning template. Silicon adatom etching of SiO2 and diffusion of adatoms to the Si3N4 regions prevented the accumulation of adatoms necessary for nanoparticle nucleation and growth on the SiO2 surfaces. Nanoparticles form selectively on Si3N4, because adsorbed Si does not etch this surface. Incident flux, total exposure, and substrate temperature were adjusted to explore nanoparticle deposition trends relating relative adatom concentration with nanoparticle density and size distributions.