Structural characterization of SinC δ layers embedded in a silicon matrix

Abstract
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 [Rücker, 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.