| 摘要 |
PURPOSE:To improve the accuracy of transfer by facilitating the tight adhesion of mask patterns to an optical waveguide layer on a substrate in photolithography and to prevent the thermal diffusion of the elements constituting a stress relief layer to the substrate and optical waveguide. CONSTITUTION:This substrate type optical waveguide 11 is constituted by providing the stress relief layer 13 between the substrate 12 and optical waveguide 15 of the substrate type optical waveguide formed with the optical waveguide 15 on the substrate 12. The stress relief layer 13 consists of a material having the coefft. of thermal expansion larger than the coefft. of thermal expansion of either the substrate 12 or the optical waveguide 15. Diffusion preventive layers may be provided on both surfaces of the stress relief layer 13. The stress relief layer 13 relieves stresses by plastic deformation at the time of cooling. The distortion of the substrate 12 is thus drastically decreased and the flatness is improved. |
