Preparation of Mg2Ge semiconductor thin films by thermal evaporation

Abstract

Preparation of thin films by thermal evaporation is a commonly used method that is simple to operate and may be easily scaled for industrialization. So we prepared Mg2Ge semiconductor thin films by resistive thermal evaporation and vacuum heat treatment. First, Mg films with thicknesses of ∼460 nm were deposited on Ge(111) substrates and then annealed at 400 °C under low vacuum (10−1–10−2 Pa) in an annealing furnace. Various annealing times 3, 4, 5, 6, and 7 h were used. The structure and morphology of each film were characterized by x-ray diffraction, scanning electron microscopy, and Raman spectroscopy. The effect of annealing time on the quality of Mg2Ge thin film growth was studied. We demonstrate that resistive thermal evaporation allows successful preparation of single-phase Mg2Ge semiconductor thin films. We observed that with increasing annealing time, the quality of Mg2Ge thin film first improves and then deteriorates, and for an annealing time of 5 h, this is optimized. Our results provide a reference for the preparation of Mg2Ge semiconductor thin films.