1. A device comprising semiconductor memories, the device comprising: a first monocrystalline silicon transferred layer; a second monocrystalline silicon transferred layer; wherein said first monocrystalline silicon transferred layer comprises a first plurality of horizontally-oriented transistors; wherein said second monocrystalline silicon transferred layer comprises a second plurality of horizontally-oriented transistors; and wherein said second plurality of horizontally-oriented transistors overlays said first plurality of horizontally-oriented transistors.