1. A method for manufacturing a memory device, the method comprising: bonding a first single crystal semiconductor body to a surface of a first layer of insulating material, and splitting the first single crystal semiconductor body on a plane generally parallel to the surface of the first layer of insulating material, leaving a first layer of single crystal semiconductor bonded on the first layer of insulating material; forming a second layer of insulating material on the first layer of single crystal semiconductor material; bonding a second single crystal semiconductor body to a surface of the second layer of insulating material, and splitting the second single crystal semiconductor body on a plane generally parallel to the surface of the second layer of insulating material, leaving a second layer of single crystal semiconductor bonded on the second layer of insulating material; and processing the first and second layers of single crystal semiconductor layer to form a 3D memory array.