Image-sensor structure and method of making thereof

Abstract

Some embodiments relate to an integrated circuit (IC) image sensor having an array of pixel elements. Each pixel element of the array includes a semiconductor substrate having a first surface and an opposite second surface, a photodetector disposed within the substrate, and a portion of an interconnect structure disposed over the first surface of the semiconductor substrate. The interconnect structure includes conductive interconnects embedded in dielectric layers. The portion of the interconnect structure includes a photodetector gate electrode over the photodetector, and a capacitor. The pixel element has a footprint over the first surface. The capacitor has a footprint over the first surface. The footprint of the capacitor covers more than half of the footprint of the pixel element, which provides increased protection to the photodetector during manufacturing.