An integrated device, the device including: a first level including a first mono-crystal layer, the first mono-crystal layer including a plurality of single crystal transistors; an overlaying oxide on top of the first level; a second level including a second mono-crystal layer, the second level overlaying the oxide, where the second mono-crystal layer includes a plurality of first image sensors and alignment marks; and a third level overlaying the second level, where the third level includes a plurality of second image sensors, where the third level is aligned to the alignment marks, where the second level is bonded to the first level, and where the bonded includes an oxide to oxide bond.