Inductively coupled plasma-enhanced chemical vapor deposition of SiO2 and GeO2-SiO2 films for optical waveguides using tetraethylorthosilicate and tetramethylgermanium

SiO2 and GeO2-SiO2 films have been deposited by employing inductively coupl ed plasma-enhanced chemical Vapor deposition (ICP-CVD) from tetraethylortho silicate (TEOS) and oxygen discharge using tetramethylgermanium (TMGe) as a dopant. A pure SiO2 film deposited with TEOS:O-2 at a flow rate ratio of 1 7% and an operating pressure of 5 Pa showed a low wetetching rate of 114 nm /min approaching that of a thermally grown oxide. Ge doped SiO2 films were deposited at various TMGe flow rates, and it was found that Ge was incorpor ated into the him as a replacement for Si. The refractive index of the film is in proportion to the Ge content in the film. Fourier transform infrared (FTIR) analysis confirmed that there were few O-H and C-H defects in the f ilms. Optical waveguides were fabricated using ICP-CVD and reactive ion etc hing (RIE). A propagation loss of 0.027 dB/cm at 1.55 mu m was achieved for the optical waveguide by using GeO2-SiO2 film as the core layer.