High resolution TEM observation of CVD diamond films
The film grown in the annular ring region has a predominant <100> growth texture, and it is defect-free within the <100> textured diamond crystal grains (Fitzgerald et al 1999). When the HRTEM observations were carried out within the square or rectangular shaped <100> textured diamond crystals, all of the lattice images acquired showed a square lattice configuration which corresponds to the (100) plane of the diamond lattice. A typical lattice image taken within a crystal grain is shown in Fig.la. In this micrograph, the bright spots represent Οιέ projection of chains of atoms onto the (100) diamond plane. The marked white square in Fig. la is the projected image of the diamond cubic unit cell and the smallest interatomic distance in this <100> projection was measured to be 0.126 nm. Fig.lb shows the lattice image obtained after tilting to the <110> direction. The horizontal expanded bright spots correspond to projection of the dumbbells (see the inset in Fig. lb). Because of the resolution limit the two column carbon atoms cannot be well resolved.