A novel method for growing polycrystalline Ge layer by using UHVCVD

Poly-Ge grown on SiO2 substrates by using one-step ultra-high vacuum chemical vapor deposition (UHVCVD) process with thin Si nucleation layers at very low deposition temperature (350 °C) was demonstrated. The results demonstrated that the polycrystalline silicon (poly-Si) nucleation layer is needed for the growth of polycrystalline germanium (poly-Ge) on SiO2 substrates at low growth temperature. SEM image presents the films with uniform grain size and uniform thickness occurring in the samples. The grain size of poly-Ge is about 100 nm. The Raman shift spectrum and XRD spectrum also identified that films are high quality poly-Ge by using this method.