Structural and Electrical Properties of Mg–Si Thin Films Fabricated by Radio-Frequency Magnetron Sputtering Deposition

Abstract

ABSTRACTMg–Si thin films were fabricated on glass, Si(100), Si(111), and polycrystalline Al2O3 substrates by radio-frequency (RF) magnetron sputtering deposition using an elemental composite target composed of Si chips on a Mg disk. The effect of deposition conditions such as the composition ratio of Mg/Si in the target area, substrate temperature, and the type of substrate on the thin film deposition was investigated. By controlling the deposition conditions, pure-phase Mg2Si polycrystalline films were successfully fabricated at room temperature. The crystalline orientation of the films was strongly influenced by the Mg/Si elemental composition ratio in the targets as well as by the surface roughness and porosity of the substrate. The electron concentration and mobility of nondoped Mg2Si films were 2.2 × 1016 cm-3 and 2.0 cm2/Vs, respectively. The electron concentration of Mg2Si films was drastically increased by impurity doping with Al and Bi.