The role of stress and percolation effects on the anodic silicon oxides growth mechanism

The present work is aimed at studying the mechanisms responsible for anodic oxide growth on silicon in strong inorganic acids. We have analyzed the mo rphology and chemical composition by using the methods of X-ray reflectivit y (XR), Dynamic Secondary Ion Mass Spectroscopy (SIMS) and Scanning Electro n Microscopy (SEM). To interpret the data of oscillatory oxide growth we as sumed that the effect is due to combination of mechanical stress in the oxi de film and of percolation transport of charged ionic species inside the po res. High current densities are beneficial for stress relaxation via detach ment or successively grown oxide layers and formation of layered oxide stru ctures.