Patent ID: 7810740

Claim:
A back illuminated photodiode array comprising: a first conductive type semiconductor substrate having a light-incident surface and an opposite surface with a plurality of recessed portions located opposite said light-incident surface; and a plurality of spatially separated second conductive type semiconductor regions, wherein one of said second conductive type regions is located at each bottom of said recessed portions; wherein said second conductive type semiconductor regions each individually constitute a pn junction together with said first conductive type semiconductor substrate, wherein said first conductive type semiconductor substrate is thinner in said recessed portions of said first conductive type substrate than in portions of said first conductive type semiconductor substrate located around said recessed portions, and wherein each of said recessed portions of said first conductive type semiconductor substrate is surrounded by portions of said first conductive type semiconductor substrate that form a frame part, located between a plurality of said recessed portions, which is thicker than and frames the respective recessed portion.