Three-dimensional memory devices and methods for forming the same

Abstract

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 semiconductor layer is between the bonding interface and the second peripheral circuit. The polysilicon layer is between the first semiconductor layer and the second semiconductor layer.