Growth of (110)-oriented CeO2 layers on (100) silicon substrates

CeO2 layers epitaxially grown on (100) silicon substrates by electron-beam evaporation were investigated and proved to have (110) orientation. X-ray diffraction measurements showed the CeO2 layers consist of more than 98% volume fraction of the (110) component. Cross-sectional high-resolution transmission electron microscopy and selected-area electron diffraction clearly verified the above configuration of crystallographic orientations and that the 〈100〉 direction in the CeO2(110) plane is parallel with the 〈110〉 direction in the Si(100) plane. The cross-sectional lattice image clarified the existence of a ∼60-Å-thick intermediate amorphous layer between the CeO2 layer and the silicon substrate. Moreover, the high density of defects such as dislocations and low-angle boundaries that exist in the vicinity of the interface agree well with Rutherford backscattering and channeling measurements.