title: Controlling spatial density and size of nanocrystals by two-step atomic layer deposition.
abstract: Two-step atomic layer deposition (ALD) is proposed in order to control both the spatial density and size of nanocrystals (NCs) via modulation of the nucleation rate during deposition. In this process, two different deposition conditions are sequentially used: a high nucleation rate condition for the formation of high density NCs and a low nucleation rate condition with a slow growth rate for the subsequent growth of pre-formed NCs. To control the nucleation rate of Ru during ALD, pulsing time and carrier flow rate of the Ru precursor are varied. By controlling those factors, both the film growth rate and a nucleation rate of Ru are decreased considerably. Two-step ALD of Ru NCs using the surface-saturated condition followed by the reduced condition allows for variation of the spatial density from 7.9 × 10(11) to 3.2 × 10(12) cm(-2) and variation of the average diameter from 1.9 to 3.3 nm.
authors.affiliation: Department of Materials Science and Engineering, Seoul National University, Seoul, Korea.
authors.forename: Do-Joong
authors.initials: DJ
authors.lastname: Lee
authors.forename: Sung-Soo
authors.initials: SS
authors.lastname: Yim
authors.forename: Ki-Su
authors.initials: KS
authors.lastname: Kim
authors.forename: Soo-Hyun
authors.initials: SH
authors.lastname: Kim
authors.forename: Ki-Bum
authors.initials: KB
authors.lastname: Kim
mesh_terms: D003460:Crystallization / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D012413:Rubidium / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D012413:Rubidium