The interface structure of wafer fused InP to Silicon at 220 degrees C was investigated by high-resolution transmission electron microscopy (TEM) and micro-Raman spectroscopy. TEM measurements reveal the formation of a thin amorphous layer with the presence of a few nanocrystallites at the interface. Cross-sectional Raman scattering measurements carried out on the cleaved interface regions show a clear evidence of nanocrystalline silicon fractions within the nonstoichiometric silicon oxides. Because micro-Raman probing is sensitive to atomic scale disorder and crystallite size, Raman line shape analysis has also been explored to confirm the formation of nanocrystalline silicon (nc-Si) at the bonded interface. (C) 2005 The Electrochemical Society.