Two-dimensional thermal oxidation of silicon—I. Experiments

With continued miniaturization and the development of new devices, the highly nonuniform oxidation of two-dimensional non-planar silicon structures is playing an increasingly important role. An understanding of this subject has been limited by insufficient experimental data and difficulties in two-dimensional numerical simulation. This paper introduces a unique experimental approach in which extensive data were obtained concerning the oxidation of cylindrical silicon structures of controlled radii of curvature. It is quantitatively demonstrated that the oxidation of curved silicon surfaces is retarded at low temperatures and sharp curvatures, and that the retardation is more severe on concave than convex structures. These observations will be interpreted using a physical model based on stress effects on oxide growth parameters. The theoretical analysis and modeling will be reported in detail in a separate paper [1].