Atomic force microscopy and secondary ion mass spectrometry measurements were performed on high-temperature (1320C) annealed structures which consisted of oxide samples that were sandwiched between polycrystalline Si and monocrystalline Si. Enhanced O out-diffusion from the SiO2 film, and the growth of SiO2 protrusions into the polycrystalline Si, were observed. This caused interfacial roughening which penetrated into the polycrystalline Si by up to 100nm. Only slight roughening was observed at the interface with monocrystalline Si. It was suggested that the presence of grain boundaries accelerated O out-diffusion.

R.A.B.Devine, D.Mathiot, J.B.Xu, I.H.Wilson, M.Gauneau, W.L.Warren: Thin Solid Films, 1996, 286[1-2], 317-20