| abstract |
Embodiments of 3D memory devices and methods of forming the same are disclosed. In an example, a 3D memory device includes a memory stack layer, a first semiconductor layer, a support structure, a second semiconductor layer, and a plurality of channel structures. The memory stack layer includes vertically interleaved conductive and dielectric layers, and has a core array region and a stepped region in plan view. The first semiconductor layer is over and overlapping the core array region of the memory stack. The support structure is above and overlapping the stepped area of the storage stack. The support structure and the first semiconductor layer are coplanar. The second semiconductor layer is over and in contact with the first semiconductor layer and the support structure. Each channel structure extends vertically through the first semiconductor layer and the core array region of the memory stack into the second semiconductor layer. |