Patent ID: 7557397

Claim:
A pixel, comprising: a substrate of a first conductivity type and having a surface; a photodetector of a second conductivity type that is opposite the first conductivity type; a floating diffusion region of the second conductivity type; a transfer region between the photodetector and the floating diffusion; a gate positioned above the transfer region and partially overlapping the photodetector; a pinning layer of the first conductivity type extending at least across the photodetector from the gate; a channel implant of the first conductivity type; and a counter doping implant of the second conductivity type positioned below the channel implant, the channel implant and the counter doping implant each extending from between a midpoint of the transfer gate and the floating diffusion to at least across the photodetector, wherein the channel implant has a dopant concentration such that a dopant concentration of the transfer region is greater proximate to the photodetector than the floating diffusion, and wherein the counter doping implant has a dopant concentration which at least compensates for a doping of the substrate in an area of the transfer region below the channel implant such that a fully-buried channel is formed in the transfer region between the photodetector and floating diffusion when the transfer gate is energized.