| 摘要 |
PROBLEM TO BE SOLVED: To provide a low propagation loss optical waveguide which can be manufactured easily at a low cost, and has a small bend radius and little propagation loss, and to provide a manufacturing method therefor. SOLUTION: The low propagation loss optical waveguide is characterized in that a substrate with a monocrystal layer of Si, SiGe, or Ge, is used to form the optical waveguide on the monocrystal layer, and minute surface roughness present on the side face of the optical waveguide is improved by heat-treating the optical waveguide in a atmosphere of argon at a temperature of 500 to 1350°C. In addition, it is desirable to use SOI, SGOI, or GeOI for the substrate. Further, it is recommended to remove a natural oxidation film on the monocrystal surface by immersing it in a fluorine-ion containing aqueous solution before the heat treatment. A top clad layer is just to be formed after the heat treatment if required, and can be formed using a CVD method represented by plasma CVD or a PVD method such as a sputtering method. COPYRIGHT: (C)2007,JPO&INPIT |
