Title :
Morphology and structure in dielectric anodic alumina
Author :
Sukonnik, I. ; Forster, J.
Author_Institution :
Texas Instrum. Inc., Dallas, TX, USA
Abstract :
The morphology and microstructure affecting the dielectric and other properties of anodic aluminum oxide were studied. It was found that the structure of the anodic film closely resembles materials produced by cathodic deposition or the solidification of liquid metals. The anodic film was characterized by a banded, compressively stressed, and columned microstructure which contains randomly-oriented voids (porosity). It is proposed that film formation is based on the diffusion of aluminum ions in the oxide. It is demonstrated that the properties and morphology of the film are affected by the composition and the microstructure of the aluminum substrate and the chemistry of the electrolyte
Keywords :
alumina; anodised layers; crystal microstructure; crystal morphology; dielectric thin films; electric strength; fracture; permittivity; scanning electron microscope examination of materials; surface structure; Al ion diffusion; SEM image; anodic film; banded film structure; cathodic deposition; compressive fracture; dielectric anodic Al2O3; electrolyte chemistry; liquid metals; microstructure; morphology; porosity; randomly-oriented voids; solidification; tensile fracture;
Conference_Titel :
Dielectric Materials, Measurements and Applications, 1988., Fifth International Conference on
Conference_Location :
Canterbury
Print_ISBN :
0-85296-359-9
