Coherent x-ray diffraction imaging of silicon oxide growth

We have measured the morphology of Si samples as a function of time in air after stripping of the native oxide. For this purpose we examined the reflectivity of a coherent beam of x rays, which produces a structured diffraction pattern. We have made further progress in the development of an inversion algorithm for conversion of these patterns into one-dimensional height images. Nanometer-sized features are found to grow and evolve in waves across the surface on the time scale of minutes to hours.