PROTECTION RING FOR IMAGE SENSORS

摘要

Some embodiments of the present disclosure provide an image sensor. The image sensor includes a pixel sensor array including a plurality of photosensors arranged in a semiconductor substrate. Peripheral circuitry is arranged in or on the semiconductor substrate and is spaced apart from the pixel sensor array. A protection ring circumscribes an outer perimeter of the pixel sensor array and separates the pixel sensor array from the peripheral circuitry. The protection ring has an annular width of greater than 20 microns. The protection ring includes a first ring in the substrate neighboring the pixel sensor array, a second ring circumscribing the first ring and meeting the first ring at a first p-n junction, and a third ring circumscribing the second ring and meeting the second ring at a second p-n junction.