A 3D semiconductor device, the device comprising: a first level comprising a first single crystal layer, said first level comprising first transistors, wherein each of said first transistors comprises a single crystal channel; first metal layers interconnecting at least said first transistors; a second metal layer overlaying said first metal layers; and a second level comprising a second single crystal layer, said second level comprising second transistors, wherein said second level overlays said first level, wherein at least one of said first transistors controls power delivery for at least one of said second transistor, wherein said second level is directly bonded to said first level, and wherein said bonded comprises direct oxide to oxide bonds.