REACTION AND REGROWTH CONTROL OF CEO2 ON SI(111) SURFACE FOR THE SILICON-ON-INSULATOR STRUCTURE

The interface structure of CeO2/Si(111) grown by laser ablation in ultrahigh vacuum was investigated by, reflection high-energy electron diffraction (RHEED), high resolution transmission electron microscopy (HRTEM), and Auger electron spectroscopy (AES). The deposited film was single-crystalline CeO2. However, during the deposition, a reaction between CeO2 and Si occurred at the interface, that resulted in the formation of an oxygen deficient amorphous CeO2-x and SiO2 layer. Post annealing in oxygen atmosphere caused the regrowth of crystalline CeO2 from CeO2-x and increased of the SiO2 thickness. The modified structure of CeO2/SiO2/Si is expected to be useful as a silicon-on-insulator structure since it maintains the desirable SiO2/Si interface followed by a single-crystal insulating film lattice-matched to Si.