Characterization of Ge-doped silica films with low optical loss grown by flame hydrolysis deposition

摘要

Ge-doped silica films have been deposited on Si substrates from SiCl_4, GeCl_4, and H_2/O_2 by flame hydrolysis deposition (FHD), and annealed to 1150℃ for 2 h. X-ray photoelectron spectroscopy (XPS) showed that the positions of the peaks correspond to the Si, O, Ge, and C levels for Ge-doped SiO_2 film. Furthermore, the optical properties of the samples using Variable Angle Spectroscopic Ellipsometry (VASE) illustrate that the refractive index of the samples increase with the increasing GeCl_4 flow ratio which indicates that the amount of germanium incorporated into the films increase. We also contrast the refractive indices of samples annealed to different temperatures. When the GeO_2 content to SiO_2 is equal to 16.28% (the atom ratio of Ge and Si is 10:90), the optical loss of the film is less than 0.527 dB/cm at 1550 nm.