MULTILAYER REFLECTIVE STACK FOR REDUCING CROSSTALK IN SPLIT PIXEL IMAGE SENSORS

An image sensor comprising a semiconductor substrate, a plurality of photodiodes, a multilayer reflective stack, and a dielectric layer is disclosed. The plurality of photodiodes is disposed within the semiconductor substrate and includes a first photodiode and a second photodiode adjacent to the first photodiode. The multilayer reflective stack comprises a first material having a first refractive index and a second material having a second refractive index. The dielectric layer has a third refractive index and is disposed between the first photodiode and the multilayer reflective stack. The first material is disposed between the second material and the dielectric layer. The first refractive index is greater than the second refractive index and the third refractive index.