The invention relates to a backside illuminated
image sensor and a preparation method thereof, and
electronic equipment, and relates to the technical field of integrated circuits, the backside illuminated
image sensor comprises a substrate, and photodiodes and laminated isolation structures which are located on the substrate, are alternately arranged along a first direction parallel to the surface of the substrate, and extend along the direction towards the substrate. The
photodiode comprises an
isolation layer, a first photosensitive layer, a second photosensitive layer and a third photosensitive layer which are sequentially stacked in the direction away from the substrate. The first photosensitive layer internally comprises a plurality of first SiP
layers arranged at intervals in the first direction, and the first SiP
layers penetrate through the first photosensitive layer in the second direction and extend to the
isolation layer. And the third photosensitive layer internally comprises a plurality of second SiP
layers which are arranged at intervals along the first direction, and the plurality of second SiP layers penetrate through the third photosensitive layer along the second direction and extend to the second photosensitive layer, so that the number of
photon-generated carriers can be increased, and the
quantum efficiency of the device can be improved.