Light detection device and distance measurement apparatus

Abstract

A light detection device according to an embodiment of the present disclosure includes: a semiconductor substrate that includes a first surface and a second surface opposed to each other, and includes a pixel array in which a plurality of pixels is disposed in an array; a semiconductor layer that is provided on a side of the first surface of the semiconductor substrate; a light receiver that is provided inside the semiconductor substrate for each of the pixels, and generates carriers corresponding to a received light amount by photoelectric conversion; a multiplier that includes a first conduction-type region and a second conduction-type region sequentially stacked on the side of the first surface, at least the second conduction-type region being provided in the semiconductor layer, and that performs avalanche multiplication on the carriers generated by the light receiver; a first electrode that is provided on the side of the first surface, and is electrically coupled to the light receiver; and a second electrode that is provided on the side of the first surface, and is electrically coupled to the multiplier.