Ge-doped SiO2 glass films prepared by plasma enhanced chemical vapor deposition for planar waveguides

Ge-doped SiO2 glass films on Si(0 0 1) wafers were deposited by a plasma enhanced chemical vapor deposition (PECVD) technique. Then the effects of processing parameters on their growth and properties were systematically investigated. An increase in GeH4 flow results in a gradual rise in refractive index of the resulting films. Film growth rate significantly increases with increasing in working pressure as well as in input power. This increased growth rate produces a rougher surface and a lower refractive index. A channel waveguide, fabricated using a Ge-doped SiO2 film prepared under an optimized deposition condition as a core-waveguiding layer, shows a very low propagation loss suitable to waveguide applications. # 2004 Published by Elsevier B.V.