Solid phase growth and properties of Mg2Si epitaxial films on Si(111)

A technology of solid-phase growth of Mg 2 Si thin films from Mg and Si layers on a pre-fabricated template layer of Mg 2 Si islands on Si (111) has been developed. The optimum temperature (T=550° C) for growth of epitaxial Mg 2 Si films on Si (111) has been found. It has been shown from optical spectroscopy data that Mg 2 Si epitaxial film has a direct fundamental transition with the energy of 0.75-0.76 eV with small combined density of states. It represents transition of small number of valence electrons into Mg-Si bonding states in the conductance band. The strong absorption range (1.9-6.2 eV) corresponds to transitions from bonding to anti-bonding states.