| 摘要 |
PROBLEM TO BE SOLVED: To resolve problems about the design and machining of a dielectric layer due to a stepped part around a light receiving region and output coupler in a photo detector by making an area surrounded by an upper layer stepped part, larger than the light receiving region enough to form an optical waveguide element and light receiving region within this area. SOLUTION: When a thermally oxidated SiO2 film 4 is etched before diffusing an impurity, a stepped part 4a is left on an impurity-diffused region 2. Above a photoelectric converter element 3 having this region 2, an optical waveguide element having an optical guide 7 is provided through a dielectric layer 6, and a light receiving region 8 is provided between an optical guide layer 7 and region 2. An area surrounded by the stepped part 4a is made larger than the region 8 enough to provide the optical guide element and region 8 within this area. Thus, a guided light never passes by the top of the part 4a whereby problems about the design and machining of the layer 6 and element 3 due to the stepped part 4a can be resolved. |
