OPTICAL INTEGRATED CIRCUIT ELEMENT

摘要

PURPOSE:To facilitate the isolation and formation of integrated circuit elements by a method wherein waveguides are built of dielectric laminate film structures of SiO2, SiN, AlN, and Al2O3. CONSTITUTION:Waveguides 24-26 are built of dielectric substances. Waveguides 24 and 26 are clad layers formed of silicon oxide film (SiO2) and a waveguide 25 is a light-confining layer formed of silicon nitride film (Si3N4). Optical signals 100 entering the waveguides 24-26 are confined in the Si3N4 layer 25 equipped with a high refractive index before their are allowed to propagate. They enter photodiodes 27 and 28 to be converted into photoelectric currents, creating a voltage across the tow ends of a resistance layer 23. This results in changes in the voltage applied to a gate electrode 30 and in source.drain currents. Use of a dielectric laminate for a waveguide facilitates its forming. Insulation against photodiodes does not pose a problem any longer. These features all justify the use of this structure for the enhancement of circuit integration density.