Abstract:

The crystalline quality of the Si cap layer, the lattice location and the depth distribution of δ-doped Ge layers in Si(111) crystals grown by molecular beam epitaxy at low and high temperatures have been studied by means of double-grazing-angle Rutherford backscattering spectrometry (RBS), RBS channelling and atomic force microscopy. The crystalline quality of the Si cap layer grown at high temperature is excellent, but there are some lattice defects in the interface or in the cap layer grown at low temperature. The RBS channelling measurements show that most of the Ge atoms occupy the Si substitutional sites. The full width at half-maximum in the depth distribution of δ-doped Ge in the Si(111) crystal is determined to be 13 ± 5 Å.