Semiconductor light reception element

A semiconductor light receiving element configured to receive incidence of light in at least one wavelength band of a 1.3 μm band, a 1.55 μm band, and a 1.6 μm band and configured to generate an electrical signal according to incident light, the semiconductor light receiving element comprising:

• a substrate;
• a semiconductor stacked portion formed on a first region of the substrate;
• and
• a first electrode and a second electrode electrically connected to the semiconductor stacked portion,
• wherein the semiconductor stacked portion includes:
• a light absorption layer includes a first conductivity type region of a first conductivity type including InxGa1-xAs;
• a buffer layer of the first conductivity type disposed between the substrate and the light absorption layer;
• and
• a second region of a second conductivity type other than the first conductivity type, which is on a side of the first conductivity type region opposite to the substrate and in contact with the first conductivity type region,
• wherein the first electrode is connected to a first portion of the first conductivity type located on the substrate side with respect to the light absorption layer in the semiconductor stacked portion,
• wherein the second electrode is connected to a second portion of the second conductivity type located on the opposite side to the substrate with respect to the light absorption layer in the semiconductor stacked portion,
• wherein an In content x in the light absorption layer is equal to or greater than 0.55,
• wherein a thickness of the light absorption layer is equal to or less than 1.8 μm,
• wherein the substrate includes a front surface on which the semiconductor stacked portion is formed and a rear surface opposite to the front surface,
• wherein the semiconductor stacked portion includes a top surface on a side opposite to the substrate,
• wherein the semiconductor light receiving element is a rear surface incident type that receives light incident from the rear surface, or a front surface incident type that receives light incident from the top surface, and
• wherein the semiconductor light receiving element comprises the only one light absorption layer, and
• wherein the light absorption layer includes one layer of the first conductivity type containing InxGa1-xAs.