| 摘要 |
PURPOSE:To easily form an electrode on a flank of a ridge type light guide or between light guides by forming a metallic film on a ridge type light guide on a substrate and then providing a passivation film thereupon and flattening the light guide, and removing only the metallic film from the light guide. CONSTITUTION:The ridge type light guide 3 is formed on the substrate 1, and the metallic layer 2 is deposited according to the shape of the light guide. Then, the passivation film 4 is formed on the metallic layer 2 to flatten the ridge shape. This passivation film is thicker on outside of the light guide than on the light guide 3, and the metal 2 on the light guide is therefore exposed earlier than the metal outside the light guide when the whole substrate is etched. When the etching speed of metal is equal to or faster than that of the passivation film 4, further etching removes the metal 2 on the light guide 3, the metal on the flank of the ridge part is protected by the passivation film 4, and a flank electrode is formed. |
