Observation of the carbon layer formed on a c-BN surface at the very early stage of diamond growth

Abstract

The initial growth process of epitaxial diamond thin films on c-BN“111”, which is composed of boron (c-BN “111” B ), was characterized by scanning tunneling microscopy (STM). At the very early stage of diamond growth the c-BN “111” B surface is covered with the flat carbon layer observed by scanning electron microscopy (SEM) referred to in our previous paper. STM observation of certain parts of the carbon layer reveals that the thin platelet crystals of the order of 100 nm in diameter with epitaxial relation are piling up, and have a triangular or hexagonal shape as observed for an epitaxial diamond particle by SEM. The differences in height of the platelet crystals, which cannot be resolved by SEM, are about 0.5–5.5 nm. The platelet crystals may be diamond, while some portions of them may have no ordered structure.