A 3D semiconductor device including: a first level including a plurality of first metal layers; a second level, where the second level overlays the first level, where the second level includes at least one single crystal silicon layer, where the second level includes a plurality of transistors, where each transistor of the plurality of transistors includes a single crystal channel, where the second level includes a plurality of second metal layers, where the plurality of second metal layers include interconnections between the transistors of the plurality of transistors, and where the second level is overlaid by a first isolation layer; and a connective path between the plurality of transistors and the plurality of first metal layers, where the connective path includes a via disposed through at least the single crystal silicon layer, and where the via includes contact with at least one of the plurality of transistors.

A 3D semiconductor device including: a first level including a plurality of first metal layers; a second level, where the second level overlays the first level, where the second level includes at least one single crystal silicon layer, where the second level includes a plurality of transistors, where each transistor of the plurality of transistors includes a single crystal channel, where the second level includes a plurality of second metal layers, where the plurality of second metal layers include interconnections between the transistors of the plurality of transistors, and where the second level is overlaid by a first isolation layer; and a connective path between the plurality of transistors and the plurality of first metal layers, where the connective path includes a via disposed through at least the single crystal silicon layer, and where the via includes contact with at least one of the plurality of transistors.

Three-dimensional (3D) memory devices and methods for forming the same are disclosed. In certain aspects, a stack structure includes interleaved dielectric layers and conductive layers, a channel structure extending in the stack structure, and a doped semiconductor layer arranged on the stack structure. The doped semiconductor layer covers an end of the channel structure and the stack structure, the channel structure includes a channel layer, and the channel layer includes a doped channel layer.

In certain aspects, a three-dimensional (3D) memory device includes a first semiconductor structure, a second semiconductor structure, a third semiconductor structure, a first bonding interface between the first semiconductor structure and the second semiconductor structure, and a second bonding interface between the second semiconductor structure and the third semiconductor structure. The first semiconductor structure includes an array of memory cells and a first semiconductor layer in contact with sources of the array of NAND memory strings. The second semiconductor structure includes a first peripheral circuit of the array of memory cells including a first transistor, and a second semiconductor layer in contact with the first transistor. A third semiconductor structure includes a second peripheral circuit of the array of memory cells including a second transistor, and a third semiconductor layer in contact with the second transistor. The second semiconductor layer is between the first bonding interface and the first peripheral circuit. The third semiconductor layer is between the second bonding interface and the second peripheral circuit.

In certain aspects, a three-dimensional (3D) memory device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes an array of memory cells, a first peripheral circuit of the array of memory cells, and a polysilicon layer between the array of memory cells and the first peripheral circuit. The first peripheral circuit includes a first transistor. The second semiconductor structure includes a second peripheral circuit of the array of memory cells. The second peripheral circuit includes a second transistor.

In certain aspects, a three-dimensional (3D) memory device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first semiconductor structure and the second semiconductor structure. The first semiconductor structure includes a first semiconductor layer, an array of NAND memory strings, and a first peripheral circuit of the array of NAND memory strings. Sources of the array of NAND memory strings are in contact with a first side of the first semiconductor layer. The first peripheral circuit includes a first transistor in contact with a second side of the first semiconductor layer opposite to the first side. The second semiconductor structure includes a second semiconductor layer and a second peripheral circuit of the array of NAND memory strings. The second peripheral circuit includes a second transistor in contact with the second semiconductor layer.

A three-dimensional (3D) memory device includes a first substrate, a first semiconductor structure, and a second semiconductor structure. The first semiconductor structure is disposed on the first substrate. The first semiconductor structure includes a second substrate, and a peripheral device disposed over the second substrate, and the peripheral device is formed facing the first substrate. The second semiconductor structure is disposed on the first semiconductor structure. The second semiconductor structure includes a doped semiconductor layer, and a memory array structure disposed between the doped semiconductor layer and the first semiconductor structure.

In certain aspects, a three-dimensional (3D) memory device includes a first semiconductor structure, a second semiconductor structure, and a bonding interface between the first and second semiconductor structures. The first semiconductor structure includes an array of NAND memory strings, a first peripheral circuit of the array of NAND memory strings including a first transistor, a polysilicon layer between the array of NAND memory strings and the first peripheral circuit, and a first semiconductor layer in contact with the first transistor. The polysilicon layer is in contact with sources of the array of NAND memory strings. The second semiconductor structure includes a second peripheral circuit of the array of NAND memory strings including a second transistor, and a second semiconductor layer in contact with the second transistor. The second peripheral circuit is between the bonding interface and the second semiconductor layer. The first semiconductor layer is between the polysilicon layer and the second semiconductor layer.

Three-dimensional (3D) memory devices and methods for forming the same are disclosed. In certain aspects, a 3D memory device includes a first semiconductor assembly, a second semiconductor assembly, and an inter-assembly bonding layer between the first semiconductor assembly and the second semiconductor assembly. The first semiconductor assembly includes a first array structure and a first periphery structure. The first array structure includes a first memory stack having a plurality of interleaved stack conductive layers and stack dielectric layers. The first periphery structure includes a plurality of first peripheral circuits electrically connected to the first memory stack. The second semiconductor assembly includes a second array structure and a second periphery structure. The second array structure includes a second memory stack having a plurality of interleaved stack conductive layers and stack dielectric layers. The second periphery structure includes a plurality of second peripheral circuits electrically connected to the second memory stack.

In certain aspects, a three-dimensional (3D) memory device includes a first semiconductor structure, a second semiconductor structure, a third semiconductor structure, a first bonding interface between the first semiconductor structure and the second semiconductor structure, and a second bonding interface between the first semiconductor structure and the third semiconductor structure. The first semiconductor structure includes an array of NAND memory strings and a first semiconductor layer in contact with sources of the array of NAND memory strings. The second semiconductor structure includes a first peripheral circuit of the array of NAND memory strings including a first transistor, and a second semiconductor layer in contact with the first transistor. A third semiconductor structure includes a second peripheral circuit of the array of NAND memory strings including a second transistor, and a third semiconductor layer in contact with the second transistor. The second semiconductor layer is between the first bonding interface and the first peripheral circuit. The second peripheral circuit is between the second bonding interface and the third semiconductor layer.