Surface-Morphological Information in RHEED

Surface-morphological information obtainable from RHEED intensity and its oscillation is studied based on multiple scattering calculations. The surface atomic density and the surface step density are used as the measure of surface morphology. RHEED intensity variations from growing surfaces produced by a Monte Carlo simulation are calculated by using large unit mesh surfaces. The homoepitaxial growth on Si(100) is taken as an example. The results show that RHEED intensity varies primarily as a function of surface atomic density at a low glancing angle as long as the surface island is not so large (less than 20 atomic units). RHEED intensity variations as a function of the surface step density are calculated from surfaces with different surface step density but the same atomic density. It turns out that the dominance of the information between the surface atomic density and the surface step density can be changed by choosing the diffraction condition of the incident beam.