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

摘要

Selective silicon nanoparticle deposition from disilane on ～17nm diameter Si_3N_4 features defined through a 15-nm-thick SiO_2 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 × 10~(10)cm~(-2) that served as the patterning template. Silicon adatom etching of SiO_2 and diffusion of adatoms to the Si_3N_4 regions prevented the accumulation of adatoms necessary for nanoparticle nucleation and growth on the SiO_2 surfaces. Nanoparticles form selectively on Si_3N_4, 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.