Waveguide type photodetector and a method of fabricating the same

摘要

In a waveguide type photodetector for receiving and detecting a light guided thereinto, a groove is formed in a semiconductor substrate, a waveguide layer is formed on the semiconductor substrate, and a light absorbing layer for absorbing a light propagated through a waveguide in the waveguide layer is formed on the waveguide layer. The waveguide is formed as a three-dimensional waveguide formed in the waveguide layer due to the presense of the groove. The three-dimensional waveguide is maintained also under the light absorbing layer since the refractive index of a portion layered on the groove formed in the substrate is made large than that of portions other than this portion layered above the groove.