Characterization of roughness and defects at an Si/SiO2 interface formed by lateral solid phase epitaxy using high-resolution electron microscopy

Abstract
Using high‐resolution transmission electron microscopy, we have characterized on an atomic scale the interfacial roughness and the interfacial defects at the Si/SiO2 interface obtained by lateral solid phase epitaxial growth of Si on SiO2. At the matrix/SiO2 interface, the protrusions of Si with 2–3 Si(200) lattice planes make the interface indented. These images can be explained by the pyramid‐type or edge‐type pseudo Si(100)/SiO2 interface models composed of small {111} facets. Defects, mainly microtwins, are localized only within 50 nm from the interface, and are adjacent to the SiO2. It indicates that microtwins are interface‐related and are supposed to form from atomic scale indents of the original a‐Si/SiO2 interface.