Oxygen distribution in the heteroepitaxially grown Y₂O₃ films on Si substrates

Crystallographic features of the heteroepitaxially grown yttrium oxide films on Si (1 0 0) and Si (1 1 1) substrates by ultra-high vacuum ionized cluster beam (UHV-ICB) were investigated by non-Rutherford backscattering spectrometry/ channeling. The heteroepitaxially grown Y₂O₃ films with 1080 Å thick on Si (1 0 0) and Si (1 1 1) were completely stoichiometric with the composition ratio of Y/O= 1/1.5 regardless of substrates. Channeling minimum yields of Y₂O₃ films on Si (1 0 0) and Si (1 1 1) are 0.39 and 0.10, respectively, which were much smaller values than the minimum values (>0.8) of Y₂O₃ films on Si substrates deposited by other methods. The results of non-Rutherford backscattering spectrometry/channeling show that the oxygen atoms in heteroepitaxially grown Y₂O₃ on Si (1 1 1) substrates have reasonable crystallinity, but those on Si (1 0 0) substrates are displaced from the regular sub-lattice sites.