Surface morphology analysis in correlation with crystallinity of CeO2(110)layers on Si(100) substrates

CeO2 layers having various crystallinity are prepared in the vicinity of th e critical condition for epitaxial growth, using conventional evaporation a nd electron beam assisted evaporation. Surface morphology of CeO2 layers is studied using atomic force microscopy in correlation with crystallinity of the layer determined by reflection high energy electron diffraction. It is clearly observed that surface morphology changes with crystallinity of the CeO2 layers. Single crystal CeO2(110) layers have a nanometer-scale-period ically corrugated surface structure, which consists of (111) facets. As the crystalline quality of samples becomes worse, the number of irregular shap ed hillocks and tetrahedral hillocks increases, which correspond to distort ed (110) grains and (111)-oriented polycrystalline grains, respectively. It is found that crystalline quality is not uniform but various crystallinity regions are distributed from place to place and their population ratio cha nges according to the degree of crystalline quality. The surface of polycry stalline layers with a tendency of (111) orientation consists of tetrahedra l hillocks with irregular in-plane rotational orientations within the horiz ontal plane. These features are discussed in terms of the surface propel dc s of the substrates at the early stage of growth. [S0734-2101(00)13804-7].