Three-dimensional memory devices having transferred interconnect layer and methods for forming the same
Embodiments of three-dimensional (3D) memory devices and methods for forming the 3D memory devices are disclosed. In an example, a method for forming a 3D memory device is disclosed. A memory stack including interleaved sacrificial layers and dielectric layers is formed above a first substrate. A channel structure extending vertically through the memory stack is formed. A single-crystal silicon layer is formed in a second substrate. An interconnect layer including a bit line is formed on the single-crystal silicon layer above the second substrate. The single-crystal silicon layer and the interconnect layer formed thereon are transferred from the second substrate onto the memory stack above the first substrate, such that the bit line in the interconnect layer is electrically connected to the channel structure.
1. A method for forming a three-dimensional (3D) memory device, comprising
forming a memory stack comprising interleaved sacrificial layers and dielectric layers above a first substrate;
forming a channel structure extending vertically through the memory stack;
forming a single-crystal silicon layer in a second substrate;
forming an interconnect layer comprising a bit line on the single-crystal silicon layer above the second substrate; and
transferring the single-crystal silicon layer and the interconnect layer formed thereon from the second substrate onto the memory stack above the first substrate, such that the bit line in the interconnect layer is electrically connected to the channel structure.
2. The method of claim 1 , wherein forming the single-crystal silicon layer comprises forming a heterogeneous interface in the second substrate.
3. The method of claim 2 , wherein forming the heterogeneous interface in the second substrate comprises implanting a dopant into the second substrate.
4. The method of claim 3 , wherein the dopant comprises hydrogen.
5. The method of claim 2 , wherein transferring the single-crystal silicon layer and the interconnect layer comprises:
splitting the single-crystal silicon layer and the interconnect layer formed thereon from the second substrate along the heterogeneous interface in the second substrate; and
bonding the single-crystal silicon layer and the interconnect layer formed thereon and the first substrate in a face-to-face manner.
6. The method of claim 5 , wherein the bonding comprises hybrid bonding.
7. The method of claim 1 , wherein a thickness of the single-crystal silicon layer is between about 1 μm and about 100 μm.
8. The method of claim 1 , further comprising, after transferring the single-crystal silicon layer and the interconnect layer, forming a semiconductor device above the single-crystal silicon layer.
9. The method of claim 8 , wherein the semiconductor device comprises a peripheral device or another channel structure extending vertically through another memory stack.
10. The method of claim 1 , wherein forming the interconnect layer comprises forming the bit line in one or more interlayer dielectric (ILD) layers.
11. A method for forming a three-dimensional (3D) memory device, comprising:
forming a semiconductor device above a first substrate;
forming a single-crystal silicon layer in a second substrate;
forming an interconnect layer comprising an interconnect on the single-crystal silicon layer above the second substrate;
transferring the single-crystal silicon layer and the interconnect layer formed thereon from the second substrate onto the semiconductor device above the first substrate, such that the interconnect is electrically connected to the semiconductor device, and the single-crystal silicon layer becomes above the interconnect layer;
forming a memory stack comprising interleaved sacrificial layers and dielectric layers above the single-crystal silicon layer; and
forming a channel structure extending vertically through the memory stack, the channel structure comprising a lower plug extending into the single-crystal silicon layer and comprising single-crystal silicon.
12. The method of claim 11 , wherein forming the channel structure comprises:
epitaxially growing the lower plug at a lower end of the channel structure from the single-crystal silicon layer; and
subsequently depositing a memory film and a semiconductor channel along a sidewall of the channel structure and above the lower plug.
13. The method of claim 11 , wherein forming the single-crystal silicon layer comprises forming a heterogeneous interface in the second substrate.
14. The method of claim 13 , wherein forming the heterogeneous interface in the second substrate comprises implanting a dopant into the second substrate.
15. The method of claim 14 , wherein the dopant comprises hydrogen.
16. The method of claim 13 , wherein transferring the single-crystal silicon layer and the interconnect layer comprises:
splitting the single-crystal silicon layer and the interconnect layer formed thereon from the second substrate along the heterogeneous interface in the second substrate; and
bonding the single-crystal silicon layer and the interconnect layer formed thereon and the first substrate in a face-to-face manner.
17. The method of claim 16 , wherein the bonding comprises hybrid bonding.
18. The method of claim 11 , wherein a thickness of the single-crystal silicon layer is between about 1 μm and about 100 μm.
19. The method of claim 11 , wherein the semiconductor device comprises a peripheral device or another channel structure extending vertically through another memory stack.
20. A three-dimensional (3D) memory device, comprising:
a substrate;
a first memory stack comprising a first plurality of interleaved conductor layers and dielectric layers above the substrate;
a first channel structure extending vertically through the first memory stack;
an interconnect layer above the first memory stack and comprising a first bit line electrically connected to the first channel structure;
a bonding interface between the first memory stack and the interconnect layer; and
a single-crystal silicon layer on the interconnect layer.
21. The 3D memory device of claim 20 , further comprising:
a second memory stack comprising a second plurality of interleaved conductor layers and dielectric layers above the single-crystal silicon layer; and
a second channel structure extending vertically through the second memory stack, the second channel structure comprising a lower plug extending into the single-crystal silicon layer and comprising single-crystal silicon.
22. The 3D memory device of claim 20 , wherein the single-crystal silicon layer comprises a well between the interconnect layer and the second memory stack.
23. The 3D memory device of claim 20 , wherein a thickness of the single-crystal silicon layer is between about 1 μm and about 100 μm.
24. The 3D memory device of claim 20 , wherein the single-crystal silicon layer extends laterally along at least a width of the first memory stack.
25. The 3D memory device of claim 20 , wherein the interconnect layer comprises the bit line in one or more interlayer dielectric (ILD) layers.