Abstract: A semiconductor light-receiving element (50) is a semiconductor light-receiving element in which a multi-plication layer (2), an electric-field control layer (3), a light absorption layer (4) and a window layer (5) are sequentially formed on a semiconductor substrate (1), and a p-type region (6) is formed in the window layer (5). The p-type region (6) has a first p-type portion (14) and a second p-type portion (15) whose current multiplication factor due to light incidence is larger than that of the first p-type portion (14). The first p-type portion (14) is formed as a central portion of the p-type region (6), the central portion including a central axis (21c) perpendicular to the semiconductor substrate (1), and the second p-type portion (15) is formed on an outer periphery of the central portion in a radial direction about the central axis (21c).

Abstract: A semiconductor light-receiving element (50) is a semiconductor light-receiving element in which a multi-plication layer (2), an electric-field control layer (3), a light absorption layer (4) and a window layer (5) are sequentially formed on a semiconductor substrate (1), and a p-type region (6) is formed in the window layer (5). The p-type region (6) has a first p-type portion (14) and a second p-type portion (15) whose current multiplication factor due to light incidence is larger than that of the first p-type portion (14). The first p-type portion (14) is formed as a central portion of the p-type region (6), the central portion including a central axis (21c) perpendicular to the semiconductor substrate (1), and the second p-type portion (15) is formed on an outer periphery of the central portion in a radial direction about the central axis (21c).

Abstract: A light receiving element includes a substrate of a first conduction type, a light absorbing layer of the first conduction type formed on the substrate, a diffusion layer of a second conduction type formed on a portion of the light absorbing layer, a window layer of the first conduction type formed on the light absorbing layer so as to surround the diffusion layer and having a bandgap larger than that of the light absorbing layer, an anode electrode formed on the diffusion layer, and a cathode electrode provided on the substrate so as to contact the substrate without contacting each of the window layer and the light absorbing layer, wherein a groove is formed which surrounds a boundary between the diffusion layer and the window layer as viewed in plan and extends through the window layer and the light absorbing layer as viewed in section.

Abstract: A light receiving element includes a substrate of a first conduction type, a light absorbing layer of the first conduction type formed on the substrate, a diffusion layer of a second conduction type formed on a portion of the light absorbing layer, a window layer of the first conduction type formed on the light absorbing layer so as to surround the diffusion layer and having a bandgap larger than that of the light absorbing layer, an anode electrode formed on the diffusion layer, and a cathode electrode provided on the substrate so as to contact the substrate without contacting each of the window layer and the light absorbing layer, wherein a groove is formed which surrounds a boundary between the diffusion layer and the window layer as viewed in plan and extends through the window layer and the light absorbing layer as viewed in section.

Abstract: A method for manufacturing a semiconductor photodetector includes: forming an insulating film on a semiconductor substrate; forming an electrode on and in contact with a predetermined area of a surface of the semiconductor substrate; forming a resist on the insulating film after forming the electrode; forming a power supply layer of a metal on the resist and the electrode; plating a surface of a portion of the power supply layer with a metal coating, after forming the power supply layer, the portion overlying and being in contact with the electrode; after the plating, etching and removing a part of the power supply layer leaving a portion that is covered with the metal coating and is an extension of the electrode; and removing the resist after etching the power supply layer.

Abstract: A semiconductor light-detecting element includes: a semiconductor substrate of a first conductivity type having a band gap energy, a first principal surface, and a second principal surface opposed to the first principal surface; a first semiconductor layer of the first conductivity type on the first principal surface and having a band gap energy smaller than the band gap energy of the semiconductor substrate; a second semiconductor layer of the first conductivity type on the first semiconductor layer; an area of a second conductivity type on a part of the second semiconductor layer; a first electrode connected to the second semiconductor layer; a second electrode connected to the area; and a low-reflection film on the second principal surface. The second principal surface is a light-detecting surface detecting incident light, and no substance or structure having a higher reflection factor, with respect to the incident light, than the low-reflection film, is located on the second principal surface.

Abstract: A semiconductor light-detecting element includes: a semiconductor substrate of a first conductivity type having a band gap energy, a first principal surface, and a second principal surface opposed to the first principal surface; a first semiconductor layer of the first conductivity type on the first principal surface and having a band gap energy smaller than the band gap energy of the semiconductor substrate; a second semiconductor layer of the first conductivity type on the first semiconductor layer; an area of a second conductivity type on a part of the second semiconductor layer; a first electrode connected to the second semiconductor layer; a second electrode connected to the area; and a low-reflection film on the second principal surface. The second principal surface is a light-detecting surface detecting incident light, and no substance or structure having a higher reflection factor, with respect to the incident light, than the low-reflection film, is located on the second principal surface.

Abstract: A semiconductor photodetector includes a semiconductor substrate of a first conductivity type, a light absorption layer of the first conductivity type on the semiconductor substrate and absorbing light, a diffraction grating layer on the light absorption layer and including a diffraction grating diffracting light, a first light transmissive layer of a second conductivity type on the diffraction grating layer and transmitting light, and a second light transmissive layer of the first conductivity type on the diffraction grating layer and surrounding the first light transmissive layer, the second light transmissive layer transmitting light. The diffraction grating surrounds a region of the diffraction grating layer that is directly below the first light transmissive layer.

Abstract: A semiconductor photodetector includes a semiconductor substrate of a first conductivity type, a light absorption layer of the first conductivity type on the semiconductor substrate and absorbing light, a diffraction grating layer on the light absorption layer and including a diffraction grating diffracting light, a first light transmissive layer of a second conductivity type on the diffraction grating layer and transmitting light, and a second light transmissive layer of the first conductivity type on the diffraction grating layer and surrounding the first light transmissive layer, the second light transmissive layer transmitting light. The diffraction grating surrounds a region of the diffraction grating layer that is directly below the first light transmissive layer.

Abstract: A method for manufacturing a semiconductor photodetector includes: forming an insulating film on a semiconductor substrate; forming an electrode on and in contact with a predetermined area of a surface of the semiconductor substrate; forming a resist on the insulating film after forming the electrode; forming a power supply layer of a metal on the resist and the electrode; plating a surface of a portion of the power supply layer with a metal coating, after forming the power supply layer, the portion overlying and being in contact with the electrode; after the plating, etching and removing a part of the power supply layer leaving a portion that is covered with the metal coating and is an extension of the electrode; and removing the resist after etching the power supply layer.