Three-dimensional memory device with static random-access memory

1. A three-dimensional (3D) memory device, comprising:

a first semiconductor structure comprising a peripheral circuit, an array of static random-access memory (SRAM) cells, and a first bonding layer comprising a plurality of first bonding contacts;

a second semiconductor structure comprising an array of 3D NAND memory strings and a second bonding layer comprising a plurality of second bonding contacts; and

a bonding interface between the first bonding layer and the second bonding layer, wherein the first bonding contacts are in contact with the second bonding contacts at the bonding interface.

2. The 3D memory device of claim 1 , wherein the first semiconductor structure comprises:

a substrate;

the peripheral circuit on the substrate;

the array of SRAM cells on the substrate and non-overlapping with the peripheral circuit; and

the first bonding layer above the peripheral circuit and the array of SRAM cells.

3. The 3D memory device of claim 2 , wherein the second semiconductor structure comprises:

the second bonding layer above the first bonding layer;

a memory stack above the second bonding layer;

the array of 3D NAND memory strings extending vertically through the memory stack; and

a semiconductor layer above and in contact with the array of 3D NAND memory strings.

4. The 3D memory device of claim 3 , further comprising a pad-out interconnect layer above the semiconductor layer.

5. The 3D memory device of claim 3 , wherein the semiconductor layer comprises at least one of polysilicon or single-crystal silicon.

6. The 3D memory device of claim 1 , wherein the second semiconductor structure comprises:

a substrate;

a memory stack above the substrate;

the array of 3D NAND memory strings extending vertically through the memory stack; and

the second bonding layer above the memory stack and the array of 3D NAND memory strings.

7. The 3D memory device of claim 6 , wherein the first semiconductor structure comprises:

the first bonding layer above the second bonding layer;

the peripheral circuit above the first bonding layer;

the array of SRAM cells above the first bonding layer and non-overlapping with the peripheral circuit; and

a semiconductor layer above and in contact with the peripheral circuit and the array of SRAM cells.

8. The 3D memory device of claim 7 , further comprising a pad-out interconnect layer above the semiconductor layer.

9. The 3D memory device of claim 1 , wherein the peripheral circuit and the array of SRAM cells are stacked one over another.

10. The 3D memory device of claim 1 , wherein the first semiconductor structure comprises a first interconnect layer vertically between the first bonding layer and the array of SRAM cells, and the second semiconductor structure comprises a second interconnect layer vertically between the second bonding layer and the array of 3D NAND memory strings.

11. The 3D memory device of claim 1 , wherein the 3D memory device is packaged in at least one of an embedded multi-media card (eMMC) or a universal flash storage (UFS).

12. The 3D memory device of claim 1 , wherein each SRAM cell comprises a plurality of transistors.

13. The 3D memory device of claim 10 , wherein the array of SRAM cells are electrically connected to the array of 3D NAND memory strings through the first and second interconnect layers and the first and second bonding contacts.

14. A method for forming a three-dimensional (3D) memory device, comprising:

forming a first semiconductor structure comprising a peripheral circuit, an array of static random-access memory (SRAM) cells, and a first bonding layer comprising a plurality of first bonding contacts;

forming a second semiconductor structure comprising an array of 3D NAND memory strings and a second bonding layer comprising a plurality of second bonding contacts; and

bonding the first semiconductor structure and the second semiconductor structure in a face-to-face manner, such that the first bonding contacts are in contact with the second bonding contacts at a bonding interface.

15. The method of claim 14 , wherein forming the first semiconductor structure comprises:

forming the peripheral circuit and the array of SRAM cells on a first substrate;

forming a first interconnect layer above the peripheral circuit and the array of SRAM cells; and

forming the first bonding layer above the first interconnect layer.

16. The method of claim 15 , wherein forming the peripheral circuit and the array of SRAM cells comprises forming a plurality of transistors on the first substrate.

17. The method of claim 14 , wherein forming the second semiconductor structure comprises:

forming a memory stack above a second substrate;

forming the array of 3D NAND memory strings extending vertically through the memory stack;

forming a second interconnect layer above the array of 3D NAND memory strings; and

forming the second bonding layer above the second interconnect layer.

18. The method of claim 14 , further comprising:

thinning the second substrate to form a semiconductor layer after the bonding; and

forming a pad-out interconnect layer above the semiconductor layer.

19. The method of claim 14 , wherein the first semiconductor structure is above the second semiconductor structure after the bonding.

20. The method of claim 19 , further comprising:

thinning the first substrate to form a semiconductor layer after the bonding; and

forming a pad-out interconnect layer above the semiconductor layer.