X-cut LiNbO3 optoelectronic device passivated by silicon nitride film

Silicon nitride (Si3N4) passivation was attempted on x-cut LiNbO3 10-Gb/s optical integrated modulators. Although silicon nitride films are commonly used to chemically protect semiconductor device surfaces,1 to our knowledge, applicability of the film to rf optoelectronic devices such as high-speed LiNbO3 modulators has not been reported. The purpose of our investigation is to confirm that the silicon nitride passivation films do not degrade the electro-optic (EO) characteristics and bias-drift performance of LiNbO3 modulators.