Preparation and AFM characterization of self-ordered porous alumina films on semi-insulated gaas substrate

• Published in: Materials science in semiconductor processing 2006-02, Vol.9 (1), p.337-340
• Main Authors: Zhou, H.Y., Qu, S.C., Wang, Z.G., Liang, L.Y., Cheng, B.C., Liu, J.P., Peng, W.Q.
• Format: Article
• Language: English
• Subjects: Anodic alumina films; Anodization; Applied sciences; Electronics; Exact sciences and technology; Materials; Semi-insulated GaAs substrate
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2006.01.030

Self-ordered porous alumina films on a semi-insulated GaAs substrate were prepared in oxalic acid aqueous solutions by three-step anodization. The I–t curve of anodization process was recorded to observe time effects of anodization. Atomic force microscopy was used to investigate structure and morphology of alumina films. It was revealed that the case of oxalic acid resulted in a self-ordered porous structure, with the pore diameters of 60–70 nm, the pore density of the order of about 10 10 pore cm −2, and interpore distances of 95–100 nm. At the same time the pore size and shape change with the pore widening time. Field-enhanced dissolution model and theory of deformation relaxation combined were brought forward to be the cause of self-ordered pore structure according to I–t curve of anodization and structure characteristics of porous alumina films.