An optical semiconductor device includes: a photo detector section which includes: a first semiconductor layer of a first conductivity type formed on a surface of a semiconductor substrate of the first conductivity type, a second semiconductor layer of a second conductivity type formed on a surface of the first semiconductor layer, and an antireflection film formed on a surface of the second semiconductor layer and preventing reflection of incident light; and a circuit element section which includes: a circuit element formed on the second semiconductor layer on the semiconductor substrate, and a passivation film covering an uppermost electrode layer among electrode layers constituting the circuit element and formed out of a same material as a material of the antireflection film.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a Divisional of U.S. patent application Ser. No. 10/320,684, filed Dec. 17, 2002 now U.S. Pat. No. 6,791,153, and based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2002-63188, filed on Mar. 8, 2002. The contents of these applications are incorporated herein by reference in their entirety.
