| 摘要 |
PURPOSE: To prevent the occurrence of surface defects by depositing a second intermediate layer by a material having the same refractive index as the refractive index of an intermediate layer on this intermediate layer. CONSTITUTION: The intermediate layer 3a of the refractive index n+Δn1 and thickness H-h' is deposited on the first layer 2 having the refractive index (n) and the first intermediate layer 3a is partially etched to the form of the pattern of width W-2h' until the etched part has a thickness (h). Next, the second intermediate layer 3b consisting of the material having the same refractive index as the refractive index of the layer 3a and the thickness h' over the entire part is deposited. The thickness h+h' is sufficiently smaller so as not to contradict with the operation of a microguide. Next, the layer 5 of the material having the refractive index n+Δn2 below the refractive index of the layers 3a and 3b is deposited above the second intermediate layer 3b, by which the optical microguide is completed. As a result, the etching defects of the first intermediate layer 3a exist at the intermediate surfaces between the intermediate layers 3a and 3b, and therefore, the defects are decreased. Since the two intermediate layers have the same refractive indices, the change in the refractive indices is zero. |
