Patent ID: 7576371

Claim:
A back illuminated photodiode array comprising: a substrate of a first conductivity type having first and second surfaces; a first matrix of regions of a first conductivity type of a higher conductivity than the substrate extending into the substrate from the first surface of the substrate; a plurality of regions of a second conductivity type interspersed within the matrix of regions of the first conductivity type; a second matrix of regions of a first conductivity type of a higher conductivity than the substrate extending into the substrate from the second surface of the substrate and aligned with the first matrix, the first and second matrices not extending into the substrate to touch each other; the second surface of the substrate having a layer of the first conductivity type having a greater conductivity than the substrate; and, a plurality of contacts on the first surface for making electrical contact to the first matrix of regions of the first conductivity type and the plurality of regions of the second conductivity type; there being no electrical contact to the second matrix of regions of a first conductivity type or to the layer of the first conductivity type having a greater conductivity than the substrate on the second surface of the substrate other than through the substrate itself.