Successive nucleation and a rodlike growth of SiOx nanoparticles into the pore bottoms of an anodic alumina template

Although the SiOx nanoparticles were previously reported to electrochemically nucleate from the bottoms of the pore array formed in the AAO/Ti/Si system, new applications of anodic aluminum oxide templates, i.e., successive nucleation and a rodlike growth of SiOx nanoparticles, were observed utilizing the subsequent annealing technique after the nanoparticle precipitation. Tailoring the pore bottom profile by doping type and level of wafers also critically affected to nucleate the SiOx nanoparticles from the pore bottoms. By anodization, as previously reported, only one nanoparticle per each pore was generally precipitated from the pyramid-shaped Si-containing TiOx nanopillars; however, subsequent annealing under a low pressure of hydrogen enabled the successive precipitation of nanoparticles. Annealing under atmospheric pressure with H2 and N2 resulted in the rodlike growth of a single nanoparticle without successive nanoparticle precipitation.