Growth of magnesium silicide thin films on Si(100), Si(111) and SOI substrates during rapid thermal processing

Abstract

The polycrystalline magnesium silicide nanoscale thin films have been grown on Si(100), Si(111) and Silicon On Insulator (SOI) substrates by high-temperature treatment at various heating rates in a short time. The morphology of magnetron radio frequency – sputtered Mg films depends on sputtering conditions and on the substrate orientation, leading to the growth of polycrystalline films with dominantly Mg(002) orientation. Depending on annealing conditions the solid-state reaction of Mg2Si formation is either diffusion or interface kinetics limited. At low heating rate the Mg2Si starts to grow at relatively low temperatures and is limited by diffusion kinetics, while at high heating rates the reaction starts at temperatures as high as 300 °C indicating in rather interface or mixed kinetics limited process. The growth of Mg2Si depends on the Mg deposition and annealing conditions as well as on substrate effects on the deposited Mg film. Possible explanations for observed results are discussed. They are based on differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) studies of the grown magnesium silicide thin films.