PHOTODIODE GATE DIELECTRIC PROTECTION LAYER

摘要

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.

主权项

1. An active pixel sensor (APS), comprising:
a photodetector disposed within a semiconductor substrate; a transfer transistor comprising a first gate structure located over a first gate dielectric layer disposed above the semiconductor substrate; a reset transistor comprising a second gate structure located over the first gate dielectric layer; and a gate dielectric protection layer disposed over the first gate dielectric layer at a first location overlying the photodetector and extending from a sidewall of the first gate structure to a sidewall of the second gate structure, wherein the gate dielectric protection layer has an upper surface that is vertically below upper surfaces of the first gate structure and the second gate structure.