The analysis of the surface structure of Al-films anodically oxidized in an oxygen plasma

Abstract

The anodization of Al-films was successfully achieved in an oxygen plasma excited by a high-frequency (0.5 MHz) electromagnetic field in a quartz reactor. The surface structure and chemical states of the plasma anodized Al-films have been analysed using XPS, AES, XRD and SEM. The surface structure of anodic floating oxidised Al-films produced in the high-frequency oxygen plasma is fine and close, bright and clean and the ultraviolet reflectivity is up to 93%. The optical constants ( n 1 n 2 , k ) and the surface oxide layer thicknesses ( d) of the anodic floating oxidised Al-films have also been measured ( n 1 n 2 = 1.22–1.30; k = 6.47; d = 200 nm ) by means of ellipsometry (ELL). After oxidation the columnar crystal of the Al-film's surface vanished. The structure analysis results again prove that anodic floating oxidation in an hf oxygen plasma is a way of using the oxidation technique to distinguish features. In this paper, we give structure analysis results of the bias oxidation Al-films by hf oxygen plasma, in comparison to floating oxidation by hf oxygen plasma.