Effect of interlayer on silver-induced layer exchange crystallization of amorphous germanium thin film on insulator

Abstract

Metal-induced layer exchange (MILE) is an advanced crystallization technique for fabricating high-quality semiconductor thin films on insulating substrates at low temperatures. Here, we focused on Ag as a catalytic metal for crystallizing amorphous germanium thin films on glass through MILE. The layer exchange between Ag and amorphous Ge (a-Ge) was not simple because Ag diffused into a-Ge so fast that it crystallized the top a-Ge layer before the completion of layer exchange. To suppress Ag diffusion into a-Ge, we explored the kind of interlayer material between them as well as the growth temperature. Preparing SiO2 and GeO2 interlayers allowed for a complete layer exchange, resulting in the formation of polycrystalline Ge thin films on glass at temperatures as low as 250 °C. These findings are essential for further understanding and controlling the layer exchange phenomenon.