| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an optical waveguide capable of filling a narrow gap part having a large aspect ratio in a core pattern without forming voids. SOLUTION: A film forming pressure in film forming of an upper clad 103 by a CVD method is set at 1-40 Pa, further forming of SiO2 films 103a-103d by the CVD method and SiO2 sputtering by a rare gas ion are repeated or simultaneously performed and whereby the narrow gap between cores 102 on a quartz substrate 101 is filled with the SiO2 films 103a-103d without forming the voids. Also, since filling characteristics for cores 202 on a quartz substrate 201 by the upper clad 203 are improved by setting a film forming pressure in forming an upper clad 203 at 1-40 Pa, sputter etching for the upper clad 203 is not necessitated. |
