Morphology and structure evolution of multilayered Ge/Si quantum dots grown by magnetron sputtering

The authors prepared multilayered Si-based Ge quantum dots (Ge/Si QDs) by using the magnetron sputtering technique and reported the corresponding morphology evolution by atomic force microscope (AFM), scanning electron micrograph (SEM), X-ray photoelectron spectroscopy (XPS), Raman and X-ray diffraction (XRD) tests. The increased temperature can improve the Si-isolated-layer crystallinity and Ge atom mobility to increase the density, size, and spatial distribution uniformity of top-layer QDs. The morphology and vertical correlation between the layers of QDs at different temperatures exhibited different phenomena or laws, and had been explained in this paper. The authors’ work made it possible to control the quality of multilayer QDs by high-rate deposition technology and laid a foundation for the industrial production of multilayer QDs in the future.