Semiconductor photodetector

A semiconductor photodetector comprising:

• a substrate;
• a light-receiving mesa structure on a first surface of the substrate, the light-receiving mesa structure including semiconductor layers, the semiconductor layers including an absorption layer;
• an insulating film overlapping with the light-receiving mesa structure in a transverse direction perpendicular to a laminating direction of the semiconductor layers, the insulating film surrounding a side surface of the light-receiving mesa structure;
• a first electrode on the first surface of the substrate, the first electrode including a mesa electrode electrically connected to and in contact with a top surface of a top layer of the semiconductor layers, the first electrode including a protruding electrode on the insulating film, the protruding electrode being electrically continuous to the mesa electrode, extending outward, and overlapping with the light-receiving mesa structure in the transverse direction, the protruding electrode being smaller in width perpendicular to an extension direction than the mesa electrode;
• and
• a second electrode on the first surface of the substrate, the second electrode being electrically connected to a bottom surface of a bottom layer of the semiconductor layers.