High dynamic range cmos image sensor pixel with reduced metal-insulator-metal lateral overflow integration capacitor lag

Abstract

A pixel circuit includes a photodiode configured to photogenerate image charge in response to incident light. A transfer transistor is configured to transfer the image charge from the photodiode to a floating diffusion. A reset transistor coupled between a reset voltage source and the floating diffusion. A lateral overflow integration capacitor (LOFIC) includes an insulating region disposed between a first metal electrode and a second metal electrode. The first metal electrode is coupled to a bias voltage source, the second metal electrode is selectively coupled to the floating diffusion, and excess image charge photogenerated by the photodiode during an idle period is configured to overflow from the photodiode through the transfer transistor into the floating diffusion.