Structural analysis of silicon dioxide and silicon oxynitride films produced using an oxygen plasma

Plasma grown silicon dioxide and oxynitride layers are shown to represent, for microelectronic applications, a good alternative method to conventional thermally grown layers. Fast growth rates, together with good electrical properties are demonstrated, at low process temperatures. Growth kinetics of SiO₂ layers synthesized both in RF and microwave plasma anodization systems are presented for a wide range of substrate temperatures in the range (90-560°C). Structural properties of the films can be affected during preparation, due to radiation from the plasma and particle bombardment. For the SiO₂ layers obtained by RF anodization at 300°C, these surface structural features were investigated by scanning electron microscopy; bulk and interface dielectric properties of the layers were analyzed by spectroellipsometry. The results were correlated with electrical properties and data coming from the growth kinetics. It was found that the properties of the layers, both structural and electrical, are strongly dependent on the growth regime (linear or parabolic). Silicon oxynitride films produced by plasma anodization of silicon nitride layers are investigated by spectroellipsometry and Auger electron spectroscopy. These results are correlated with electrical measurements and used to explain the changes in film properties