Cmos image sensors including pickup regions

Abstract

A CMOS image sensor includes a field isolation film defining first, second, and third active fields in a substrate having a first conductivity type, a photodiode region in the first active field, the photodiode region having a second conductivity type opposite the first conductivity type, and a floating diffusion region of the second conductivity type in the second active field. A source follower gate is conductively connected with the floating diffusion region and intersects the second active field. First and second source/drain regions of the second conductivity type are provided in the second active field at opposite sides of the source follower gate, and a pickup region is disposed in the third active field. The third active field may be adjacent a portion of the second active field where the first source/drain region or the second source/drain region is located, and the floating diffusion region may be isolated from the first and second source/drain regions.