Method for forming a groove and method for manufacturing an optical waveguide element

Abstract

A method for forming a groove which enable exact formation of vertical wall surface and a method for manufacturing an optical waveguide element such as an optical switch and an optical multiplexer/demultiplexer applying this forming method are provided. Such method comprising forming a sacrifice covering layer having predetermined thickness over said predetermined layer, performing dry etching from upper of said sacrifice covering layer, and decreasing gas being contained in etching gas generated by said dry etching processing and containing plenty of movement component to horizontal direction by collide with a wall surface in a groove formed through said sacrifice covering layer, and forming said groove through said predetermined layer positioned under said sacrifice covering layer by gas containing mainly movement component to vertical direction.

Dependencies are inferred from the claim text.