PHOTODIODE, PHOTODIODE ARRAY, AND SOLID-STATE IMAGE PICKUP ELEMENT

摘要

A photodiode (1) that multiplies, in an avalanche region, charges generated by means of photoelectric conversion is provided with: a P- type semiconductor layer (11) having an interface (S1) and an interface (S2); an N+ type semiconductor region (12) in the P- type semiconductor layer (11), said N+ type semiconductor region being in contact with the interface (S1); an N+ type semiconductor region (13) in the P- type semiconductor layer (11), said N+ type semiconductor region being connected to the N+ type semiconductor region (12); and a P type semiconductor region (14) disposed between the N+ type semiconductor region (13) and the interface (S2). The impurity concentrations of the N+ type semiconductor region (12), the N+ type semiconductor region (13), and the P type semiconductor region (14) are higher than the impurity concentration of the P- type semiconductor layer (11), the avalanche region is a region sandwiched between the N+ type semiconductor region (13) and the P type semiconductor region (14), said avalanche region being in the P- type semiconductor layer (11), and the N+ type semiconductor region (12) has an area that is smaller than that of the N+ type semiconductor region (13) in a plan view.