Growth and Formation of Thin Anodic Films on InP

摘要

Growth, formation and stability of anodic oxides obtained on n-InP were investigated by coupling electrochemical methods and XPS analyses. Using transient photocurrent and Mott-Schottky behavior, as in situ probes, we have pointed out several steps for InP oxidation process, related to a gradual oxide coverage evidenced by XPS characterizations. The current density chosen to perform the oxidation governs the resulting chemical composition, the texture and the electrical properties of the oxide. Low applied current densities lead to the formation of thin (around few nanometers) and homogeneous films, while high current densities induce thicker and less homogeneous oxides. The resulting electrical properties also strongly depend on the anodization mode. The thinner homogeneous layers, grown with low current densities, exhibit the best passivating features.