A 3D semiconductor device, the device including: a first level including a first single crystal layer, the first level including a plurality of first transistors and at least one metal layer, where the at least one metal layer overlays the first single crystal layer, and where the at least one metal layer includes interconnects between the plurality of first transistors, the interconnects between the plurality of first transistors include forming first control circuits; a second level overlaying the at least one metal layer, the second level including a plurality of second transistors; a third level overlaying the second level, the third level including a plurality of third transistors, where the second level includes a plurality of first memory cells, the first memory cells each including at least one of the plurality of second transistors, where the third level includes a plurality of second memory cells, the second memory cells each including at least one of the plurality of third transistors, where at least one of the plurality of second memory cells is at least partially atop of the first control circuits, where the first control circuits are adapted to control data written to at least one of the plurality of second memory cells; and where the plurality of second transistors are horizontally oriented transistors.