In present paper, the fabrication of pillared microstructures by means
of multistep anodization of Ta/Al film structure on ceramic and silic
on (100) substrates is described. The main characteristics of these st
ructures, obtained by electron microscopy, are presented. Information
on geometrical parameters of porous host and pillar microstructure ele
ments has been obtained. The depth:diameter ratio ('aspect ratio') for
investigated composition was 1.7-4.0. The transport numbers T-Ta(5+)
= 0.4 and T-Al(3+) = 0.25 for the anodizing process of two-layered Ta/
Al film structure have been obtained. The features of ion transport in
thin film Ta/Al system under anodization are presented, and two versi
ons of the process of pillar growth through porous Al2O3 are proposed.
The scheme of the additive process for functional layer formation on
the base of combined anodic oxides is proposed, which may be used, in
particular, for fabrication of light-emitting structures with nanosize
d elements. (C) 1998 Elsevier Science S.A. All rights reserved.