抄録
Highly-oriented Si nanoparticles (SNP) were precipitated in amorphous SiO2 using separation by implanted oxygen (SIMOX) method and showed visible luminescence at room temperature. In order to investigate the microstructure of the SNPs, we observed the Si/SiO2 interface by cross-sectional high-resolution transmission electron microscopy (HRTEM). The three-dimensional shape of the SNPs observed from different directions is an {111}-surrounded octahedral structure, each apex of which has an {100} facet. The upper (surface-side) interface of SiO2/Si(100) contains missing atomic rows, while the lower (substrate-side) interface of Si(100)/SiO2 is atomically flat except for the steps at the intersection with (111) plane. Similar atomically sharp structures were observed at the Si{111}/SiO2 interfaces. Image-simulation of the interfaces well reproduced the microstructures observed by HRTEM and proved that the interfaces are those of amorphous SiO2 and single-crystal Si without any intermediate layer.
