| 摘要 |
PURPOSE: A method for fabricating an optical modulator element is provided to locate a bridge-type ribbon on the same plane as a substrate, and to freely control an air gap inside the substrate, thereby improving mechanical stability and reliability by stress distributions of the substrate and a flat bridge post. CONSTITUTION: A photoresist is deposited on the first insulating layer. By etching the first insulating layer and a portion of a substrate(10), an air gap is formed. After removing the first photoresist and the first insulating layer, the second insulating layer(11') is deposited on the substrate(10) where the air gap is formed. After forming a sacrificial layer(14) in height of the etched substrate(10), the second photoresist is made. By fully etching the second photoresist without a mask, the second photoresist except the second photoresist formed in an air gap portion is removed, exposing the sacrificial layer(14). By dry-etching the exposed sacrificial layer(14), the sacrificial layer(14) is removed from the substrate(10). The sacrificial layer(14) disposed in the air gap portion is protected by the remaining second photo resist. The air gap is configured with a flat lower structure filled with the sacrificial layer(14). |
