Ge_1−xSn_x alloyed films were grown on glass substrates by sequential physical vapor deposition of a biaxial CaF₂ buffer layer and a Sn heteroepitaxial layer at room temperature, followed by a Ge layer grown at low temperatures (200–350 °C). The predeposited Sn on the CaF₂ layer enhances Ge diffusion and crystallization. Sn is substituted into the Ge lattice to form a biaxial Ge_1−xSn_x alloyed film. The epitaxial relationships were obtained from X-ray pole figures of the samples with Ge_1−xSn_x 〈01〉∥CaF₂ 〈01〉 and Ge_1−xSn_x 〈10〉∥CaF₂ 〈10〉. Crystallization and biaxial texture formation start at about 200 °C with the best biaxial Ge_1−xSn_x film grown at about 300 °C, which is 100 °C lower than the growth temperature of biaxial pure Ge film without Sn on the CaF₂/glass substrate. The microstructure, texture and Sn concentration of the Ge_1−xSn_x films were characterized by X-ray diffraction, X-ray pole figure analysis, and transmission electron microscopy. The spatial chemical composition of Sn in Ge_1−xSn_x was measured by energy-dispersive X-ray spectroscopy and was found to be nearly uniform throughout the thickness of the alloyed film. Raman spectra show shifts of Ge–Ge, Ge–Sn, and Sn–Sn vibration modes due to the percentage change of substitutional Sn in Ge as a function of growth temperature. This growth method is an alternative cost-effective way to grow biaxial semiconductor films on amorphous substrates.