Patent ID: 8314924

Claim:
A method ensuring rapid collection of photonically generated charges created in an upper region of a CMOS sensor, while impeding collection of photonically generated charges created in a lower region of said CMOS sensor, the method comprising the following steps: (a) from time of generation of said photonically generated charges to time of collection of said photonically generated charges, moving said photonically generated charges created in said upper region upward toward a collection region of said sensor, said moving resulting from at least one of (i) drift field resulting from an electric field of at least 1 kV/m to urge said photonically generated charges upward toward a collection region of said CMOS sensor, and (ii) diffusion over a diffusion length of less than about 1 μm; and (b) from time of generation of said photonically generated charges, delaying upward movement of substantially all said photonically generated charges created in said lower region for a time period exceeding recombination lifetime of said photonically generated charges.