REFLECTION HIGH-ENERGY ELECTRON-DIFFRACTION DURING SUBSTRATE ROTATION- A NEW DIMENSION FOR IN-SITU CHARACTERIZATION

We present two methods to access reciprocal space with reflection high -energy electron diffraction (RHEED) during substrate rotation. The ex traction of an arbitrary number of still frames from a continuously ch anging RHEED pattern is realized by triggering the substrate rotation and it allows analysis of quasistatic RHEED patterns that are updated every revolution. At the same time, the intensity along a line paralle l to the shadow edge can be used to reconstruct a planar cut through t he reciprocal lattice similar to a low-energy electron diffraction pat tern. This RHEED pattern directly reveals the symmetry of the surface reconstruction and its changes during the deposition process. (C) 1998 American Vacuum Society.