US Patent 10388568 3D semiconductor device and system

A 3D semiconductor device, the device including: a first single crystal layer including a plurality of first transistors; at least one first metal layer interconnecting the plurality of first transistors, where the interconnecting includes forming memory peripheral circuits; a plurality of second transistors overlaying the at least one first metal layer; a second metal layer overlaying the plurality of second transistors; a first memory cell overlaying the memory peripheral circuits; and a second memory cell overlaying the first memory cell, where the first memory cell includes at least one of the second transistors, where at least one of the second transistors includes a source, channel and drain, where the source, the channel and the drain have the same dopant type.