IMAGING SENSORS WITH OPTICAL CAVITY PIXELS

摘要

An image sensor may be provided having a pixel array that includes optical cavity image pixels. An optical cavity image pixel may include a photosensitive element in a substrate and a reflective cavity formed from a frontside reflector that is embedded in an intermetal dielectric stack, a backside reflector formed in a dielectric layer above the photosensor that partially covers the photosensor, and sidewall reflectors formed in the substrate between adjacent photosensors using deep trench isolation techniques. Each optical cavity image pixel may also include a light-guide trench above the photosensor that guides light into the reflective cavity for that pixel. Each optical cavity pixel may also include color filter material in the trench. Light that is guided into the reflective cavity by the light-guide trench may experience multiple reflections from the reflectors of the reflective cavity before being absorbed and detected by the photosensor.