High-resolution x-ray diffraction and high-resolution scanning electron microscopy studies of Si-based structures with a buried amorphous layer

Structural and geometrical parameters of Si samples with buried amorphous layers, produced by oxygen implantation and high-temperature annealings, were measured by high-resolution x-ray diffraction and high-resolution scanning electron microscopy. By using a newly developed simulation procedure precise fittings of x-ray diffraction spectra were made and important parameters were derived, such as the averaged fluctuations of the thickness of the amorphous layer ("interface roughness'') and of the interplanar spacing in the Si top layer. The data obtained revealed a reduction in interface roughness, i.e., an improvement of the samples' quality after additional high-temperature annealing. This conclusion was supported by electron microscopy images demonstrating a more complete dissolution of SiO2 precipitates as a result of additional heat treatment. The importance of more sophisticated annealing was also confirmed by the Moire x-ray diffraction topographs taken on the topography beamline of the European Synchrotron Radiation Facility. (C) 1998 American Institute of Physics. [S0021-8979(98)01922-7].