Formation of Porous Alumina Integrated on Silicon Oxide Substrate
Alaa M. Abd-Elnaiem1,2 ,*, A. Gaber2, M.A. Abdel-Rahim2
1
KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh,
Saudi Arabia
2
Physics Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
*
E-mail: alaa.abd-elnaiem@science.au.edu.eg
Fabrication and characterization of porous alumina films prepared by anodization
of pure Al thin film deposited on SiO2/Si substrates are studied by the one-step
method at (0-50°C) room temperature. Three electrolytes are used: namely sulfuric
(1M), oxalic (0.3 M) and (0.75M) phosphoric acids as anodizing solutions.
Potentiostatic or galvanostatic anodization in two-electrode cell configurations are
performed. Aspects such as current transients, anodization rate, barrier layer
thickness and the interpore distance are discussed.
The barrier layer thickness and inter-pore distance are increased from 10, 25nm to
115, 220nm as the anodizing voltage increases from 10 to 90V, respectively. The
growth rate of the porous alumina is increased from 5 to 60 µm h -1 as the
anodization current densities increases from 3.3 to 38 mA cm-2 at RT. The
anodization at high current density (>30mA cm-2) is not favorable which leads to
local burns.