Patent ID: 8101981

Claim:
In a back-illuminated photodiode array, a device comprising: a structure comprised of a semiconductor of a first conductivity type, having a first conductivity, and having first and second sides; an array of photodiodes formed from the first side of the structure, each photodiode having a region of a second conductivity type with a concentration gradually decreasing towards the second side of the structure; trenches in the semiconductor structure forming an interconnected matrix surrounding each photodiode, wherein the trenches extend from the second side of the structure; the walls of the trenches doped with the first conductivity type to a second conductivity higher than the first conductivity; the trenches being filled with electrical isolation material to provide electrical isolation between adjacent photodiodes; and a region of the first conductivity type proximate to the second side of the structure, the region having a third conductivity higher than the first conductivity.