Patent ID: 6921491
Filing Date: 2005-07-26
Classification: C03C,G02B

Abstract:
1. A method for forming a groove having a vertical wall surface through a predetermined layer by dry etching said predetermined layer on which an optical waveguide element is formed, comprising: forming a sacrificial covering layer having predetermined thickness over said predetermined layer: forming a metal groove pattern on said sacrificial covering layer; performing dry etching from an upper surface of said sacrificial covering layer through said metal film groove pattern, making etching gas generated by said dry etching processing and containing a movement component in the horizontal direction that collides with a wall surface in the groove formed through said sacrificial covering layer; and forming a tapered portion of the groove at said sacrifice covering layer, said collision decreasing said movement component in the horizontal direction in said etching gas; forming the groove having vertical wall through said predetermined layer positioned under said sacrificial covering layer by said etching gas containing mainly movement component in the vertical direction and removing said sacrifice covering layer.