The grain size in microcrystalline silicon: Correlation between atomic force microscopy, UV reflectometry, ellipsometry, and X-ray diffractometry

The grain size in polycrystalline silicon thin films is approached through X-ray diffractometry, UV optical properties, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The apparent discrepancy by two orders of magnitude between SEM and X-ray sizes is resolved by AFM which reveals the existence of substructures. Very satisfying correlations are established between the different approaches. The X-ray derived mean crystal size is shown to be the relevant size and corresponds to the smallest crystals observed in microscopy.