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.