US Patent 9812477 Photodiode gate dielectric protection layer

The present disclosure relates to a method the present disclosure relates to an integrated chip having an active pixel sensor with a gate dielectric protection layer that reduces damage to an underlying gate dielectric layer during fabrication, and an associated method of formation. In some embodiments, the integrated chip has a photodetector disposed within a substrate, and a gate structure located over the substrate. A gate dielectric protection layer is disposed over the substrate and extends from along a sidewall of the gate structure to a location overlying the photodetector. The gate dielectric protection layer has an upper surface that is vertically below an upper surface of the gate structure.