The present disclosure relates to a method the present disclosure relates to an active pixel sensor having 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 active pixel sensor has a photodetector disposed within a semiconductor substrate. A transfer transistor having a first gate structure is located on a first gate dielectric layer disposed above the semiconductor substrate. A reset transistor having a second gate structure is located on the first gate dielectric layer. A gate dielectric protection layer is disposed onto the gate oxide at a position extending between the first gate structure and the second gate structure and over the photodetector. The gate dielectric protection layer protects the first gate dielectric layer from etching procedures during fabrication of the active pixel sensor.