Growth of (111)-oriented epitaxial magnesium silicide (Mg₂Si) films on (001) Al₂O₃ substrates by RF magnetron sputtering and their properties

Epitaxial Mg₂Si films with (111) orientation were successfully grown at 300 °C on (001) Al₂O₃ insulating substrates by RF magnetron sputtering method. The optimal conditions for the epitaxial growth were identified as a low deposition rate and high deposition pressure above 60 mTorr. X-ray diffraction and transmission electron microscopy analysis confirmed the growth of (111)-oriented epitaxial Mg₂Si films with the following relationship: (111) Mg₂Si//(001)Al₂O₃. The conduction type of the epitaxial films was p-type up to 450 °C, which is same conduction type of the (110)-one-axis oriented ones. The electrical conductivity of the epitaxial films was lower than that of (110)-one-axis oriented ones.