Patent attributes
The present invention provides an optical semiconductor device for improving minimization and increase of detection precision. An optical semiconductor device A1 of the present invention includes: a substrate 1, including a semiconductor material, and including a main surface 111 and a back surface 112; a semiconductor light-emitting element 7A at the substrate; a semiconductor light-receiving element 7B at the substrate; a conductive layer 3, conducting the semiconductor light-emitting element 7A and the semiconductor light-receiving element 7B; and an insulating layer 2 between at least a portion of the conductive layer 3 and the substrate; wherein the substrate 1 includes a recess 14 recessed from the main surface 111 and including a bottom surface 142A of a light-emitting side recess where the semiconductor light-emitting element 7A is disposed, and a bottom surface 142B of a light-receiving side recess where the semiconductor light-receiving element 7B is disposed; a light-emitting side transparent portion 18A for light from the semiconductor light-emitting element 7A to pass through the bottom surface 142A of the light-emitting side recess to the back surface 112; and a light-receiving side transparent portion 18B for light from the back surface 112 to pass through the bottom surface 142B of the light-receiving side recess to the semiconductor light-receiving element 7B.