| 摘要 |
PROBLEM TO BE SOLVED: To obtain a glass waveguide having low loss and good optical characteristics without producing air bubbles by subjecting a core glass waveguide after formed to a treatment with supercritical water. SOLUTION: A core glass film 22a of a TiO2-SiO2-based glass is formed by an electron beam vapor deposition method on a Si or SiO2-based substrate 20. Then a tungsten silicide (WSi) film 25a is formed by a sputtering method on the core glass film 22a. Then a photoresist pattern 26 as a mask pattern for an optical circuit of a splitter is formed on the WSi film 25a. Then WSi film is etched with NF3 gas by using the hotoresist pattern 26 as a mask and using a reactive ion etching device to form a WSi pattern 25. After the WSi pattern 25 is formed, the photoresist pattern 26 on the WSi pattern 25 is removed. Then the substrate 20 is introduced into a chamber and treated with supercritical water to remove the deposit of compounds with W, Si and the resist produced during etching. |
