Microstructure and Mg concentration of Mg–Si thin film deposited by ion beam sputtering on glass substrate Available to Purchase

Mg–Si thin films are deposited by ion beam sputtering from the target composed of Mg and Si with 50%:50% area ratios. Intermetallic compound magnesium silicide $(Mg2Si)$ films are obtained at room temperature on glass substrates. Observation of the thin film by cross sectional transmission electron microscopes indicates that films of $1μm$ thickness show a microstructure composed of a crystalline upper layer of $Mg2Si$ with columnar structure $300nm$ thick and an amorphous bottom layer with uniform structure $700nm$ in thickness. Energy dispersive x-ray measurements show that magnesium concentration in the crystalline $Mg2Si$ upper layer are larger than in the amorphous bottom layer. Moreover, the magnesium concentration at grain boundaries is larger than that in grains in the crystalline $Mg2Si$ upper layer. It is also observed that magnesium segregates on the film surface. The film formation is explained in terms of magnesium migration-to-surface and magnesium evaporation from film surface.