Three-dimensional memory device and method for forming the same

Abstract

Embodiments of 3D memory devices and methods for forming the same are disclosed. In an example, a 3D memory device includes a doped region of a substrate. The doped region includes dopants of a first type. The 3D memory device also includes a semiconductor layer on the doped region. The semiconductor layer includes dopants of a second type. The first type and the second type are different from each other. The 3D memory device also includes a memory stack having interleaved conductive layers and dielectric layers on the semiconductor layer. The 3D memory device further includes a channel structure extending vertically through the memory stack and the semiconductor layer into the doped region, a semiconductor plug extending vertically into the doped region, the semiconductor plug comprising dopants of the second type, and a source contact structure extending vertically through the memory stack to be in contact with the semiconductor plug.