Patent ID: 7462553

Claim:
A method of fabricating a photodiode array comprising: providing a semiconductor substrate of a first conductivity type having first and second surfaces; providing a first matrix of first regions of a first conductivity type of a higher conductivity than the substrate, including a high temperature diffusion, the first matrix of regions extending into the substrate from the first surface; providing a plurality of second conductivity type interspersed within the first matrix of regions of the first conductivity type, including an additional high temperature diffusion, the second region extending into the substrate from the first surface a shorter distance than the first region; grinding the substrate from the second surface to reduce the thickness of the substrate and to not expose the matrix of regions of a first conductivity type or the plurality of regions of the second conductivity type at the second surface of the substrate; providing 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, including a high temperature diffusion, the second matrix being aligned with the first matrix; providing a layer of the first conductivity type having a conductivity greater than the substrate on the second surface of the substrate; the first matrix of regions of a first conductivity type and the second matrix of regions of a first conductivity type contacting each other within the substrate; and, providing at least one electrical contact to the first matrix of regions of the first conductivity type to form one electrode of the photodiode array, and providing an electrical contact to each second region of the second conductivity type to form a second electrode for each photodiode in the array.