Sulphide GaxGe25-xSb10S65(x=0,5) sputtered films: Fabrication and optical characterizations of planar and rib optical waveguides

We report the fabrication and the physical and optical characterizations of sulphide Ga(x)Ge(25-x)Sb(10)S(65(x=0,5)) rib waveguides. High quality films fabricated on SiO(2)/Si wafer substrates were obtained using the sputtering magnetron rf deposition method. The slab waveguides obtained without annealing present propagation losses of about 0.6 dB/cm at 1550 nm. These optical losses are not important for implementation in optical devices based on silicon-on-insulator or polymer, for instance, atomic force microscopy measurements revealed low interface roughness between the different media (substrate/film and film/air). Reactive ion etching was used to pattern rib waveguides between 2 and 300 mu m wide. The parameters were optimized to obtain a dry etching process that had low surface roughness, vertical sidewalls, etch depth of more than 1 mu m, and reasonable etching rate. This technique was used to fabricate Y optical junctions for optical interconnections on chalcogenide amorphous films. Their optical transmission was demonstrated by optical near field of guided modes and optical losses were measured and discussed. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2968248]