STRUCTURAL CHARACTERIZATION OF SINC DELTA-LAYERS EMBEDDED IN A SILICON MATRIX

Besides a great variety of carbon-containing atomic complexes and precipitates in crystalline silicon, new ordered silicon-carbon structures have recently been predicted theoretically by ab initio calculations [Rucker, Methfessel, Bugiel, and Osten, Phys. Rev. Lett. 72, 3578 (1994)] to be possible in highly C-doped epitaxial layers. These layers are strain stabilized. Due to the high mismatch in lattice parameters, pseudomorphic growth is restricted to layer thicknesses of some monolayers only. Four-hundred kV high resolution electron microscopy (HREM) has been applied to study the microscopic structure of the SinC layers grown by molecular beam epitaxy on (001)-oriented silicon substrate. Local ordering of the carbon with a quasiperiodical variation of its distribution over the layer has been observed on HREM micrographs at certain imaging conditions. (C) 1995 American Institute of Physics.