Electrochemical nucleation of SiOx nanoparticles into the pore bottoms of an anodic aluminum oxide.
Utilizing the wafer-scale anodization of a thermally evaporated Ti layer onto a Si substrate, SiOx nanoparticles could be electrochemically nucleated into the pore bottoms of an anodic aluminum oxide. The formation of a Si-containing Ti layer (Ti(1-x)Six, x < 0.1) was identified between the Al and the silicon substrate by thermal diffusion of Si during the evaporation. Upon prolonged anodization of approximately 1 h after alumina barrier layer touched the Si-containing Ti layer, pyramid-shaped TiOx nanopillars formed underneath the pore bottoms as a result of a curvature inversion of the barrier oxide with Ti migration. These TiOx nanopillars were observed to act as a diffusion route of silicon from the Si-containing Ti layer. Only one SiOx nanoparticle (approximately 8 +/- 5 nm) for each pore was generally precipitated without Ti contamination. This finding suggests a new route which can make SiOx nanoparticles confined within an anodic aluminum oxide template.
Department of Chemical Engineering, Hanyang University, Ansan, 426-791, Korea.
Sang-Won
SW
Jee
Yong Woo
YW
Cho
Jun Mo
JM
Yang
Yun Chang
YC
Park
Jung-Ho
JH
Lee