Uniformity in cell size of a locally anodized porous anodic alumina film

Porous anodic alumina (PAA) has a homogeneous nanohole array structure. It is fabricated by anodizing part of an aluminum film and it has a boundary between anodized and not regions. Therefore, the anodization condition is different between the edge and the center of the anodized region. In this work, we investigate homogeneity in a cell size of a PAA film using field emission scanning electron microscope (FE-SEM). We demonstrate that the cell size distribution near the boundary is more homogeneous than that at the center of an anodization region.