Semiconductor die bonding structure

1. A semiconductor die bonding structure, comprising:

a lower die including a lower top bonding dielectric layer and lower connection structures; and

an upper die stacked over the lower die in a vertical direction and including an upper bottom bonding dielectric layer and upper connection structures,

wherein:

the lower top bonding dielectric layer and the upper bottom bonding dielectric layer are directly bonded to each other,

each of the lower connection structures includes a lower top bonding pad structure having a first width in a first horizontal direction and a second width in a second horizontal direction,

each of the upper connection structures includes an upper bottom bonding pad structure having a third width in the first horizontal direction and a fourth width in the second horizontal direction;

the first horizontal direction, the second horizontal direction, and the vertical direction are substantially perpendicular to one another,

the second width is greater than the first width, and

the second width is greater than the fourth width.

2. The semiconductor die bonding structure of claim 1 , wherein the second width is at least twice as large as the first width.

3. The semiconductor die bonding structure of claim 1 , wherein the first width is greater than the third width.

4. The semiconductor die bonding structure of claim 1 , wherein the third width and the fourth width are substantially the same.

5. The semiconductor die bonding structure of claim 1 , wherein the lower die further comprises:

a lower substrate;

a lower inter-layer dielectric layer over an active surface of the lower substrate; and

a lower wiring dielectric layer between the lower inter-layer dielectric layer and the lower top bonding dielectric layer,

wherein each of the lower connection structures further comprises:

a lower through-via structure vertically penetrating the lower substrate and the lower inter-layer dielectric layer;

a lower wiring via pad disposed over the lower inter-layer dielectric layer to contact an upper end of the lower through-via structure; and

a lower via, vertically penetrating the lower wiring dielectric layer to electrically connect the lower via pad to the lower top bonding pad structure of each of the lower connection structures.

6. The semiconductor die bonding structure of claim 5 , wherein each lower top bonding pad structure comprises:

a lower top bonding pad base disposed over the lower wiring dielectric layer to contact the lower wiring via;

a lower top bonding pad barrier layer over the lower top bonding pad base; and

a lower top bonding pad body over the lower top bonding pad barrier layer,

wherein the lower top bonding dielectric layer surrounds a side surface of the lower top bonding pad structure.

7. The semiconductor die bonding structure of claim 1 , wherein the upper die further comprises:

an upper substrate;

an upper passivation layer over a non-active surface of the upper substrate, and

the upper bottom bonding dielectric layer is disposed over a lower surface of the upper passivation layer,

wherein each of the upper connection structures further comprises an upper through-via structure connected to the upper bottom bonding structure by vertically penetrating the upper substrate and the upper passivation layer.

8. The semiconductor die bonding structure of claim 1 , wherein each upper bottom bonding pad structure is in direct contact with a central region or one end portion of each lower top bonding pad structure.

9. The semiconductor die bonding structure of claim 8 , wherein each lower top bonding pad structure has one among a segment shape extending in the second horizontal direction, a bracket shape, and an arrowhead shape.

10. The semiconductor die bonding structure of claim 8 , wherein each of the lower top bonding pad structures has one shape among an elbow shape, a T-shape, and a cross shape which has a first body portion and a second body portion extending from one end of the first body portion.

11. The semiconductor die bonding structure of claim 10 , wherein neighboring lower top bonding pad structures have a symmetrical shape.

12. The semiconductor die bonding structure of claim 11 , wherein each lower top bonding pad structure is arranged side by side in an interdigitated form such that the lower top bonding pad structures alternate in the first horizontal direction.

13. The semiconductor die bonding structure of claim 1 , wherein each lower top bonding pad structure and the upper bottom bonding pad structures are arranged side by side in two rows in the first horizontal direction, respectively.

14. The semiconductor die bonding structure of claim 13 , wherein each lower top bonding pad structure and the upper bottom bonding pad structures are arranged in zigzag in the first horizontal direction, respectively.

15. A semiconductor die bonding structure, comprising:

a lower die including a lower top bonding dielectric layer and a lower connection structure; and

an upper die stacked over the lower die and including an upper bottom bonding dielectric layer and an upper connection structure,

wherein the lower connection structure comprises:

a lower through-via structure including a lower through-via plug, a lower through-via barrier layer surrounding a side surface of the lower through-via plug, and a lower through-via liner layer surrounding a side surface of the lower through-via barrier layer, wherein the lower through-via structure penetrates the lower substrate in a vertical direction; and

a lower top bonding pad structure including a lower top bonding pad base, a lower top bonding pad barrier layer over the lower top bonding pad base, and a lower top bonding pad body over the lower top bonding pad barrier layer,

wherein:

the lower top bonding dielectric layer and the upper bottom bonding dielectric layer are directly bonded to each other,

the lower top bonding pad structure and the upper connection structure are bonded to each other,

an upper surface of the lower connection structure has a first width in a first horizontal direction and a second width in a second horizontal direction,

a lower surface of the upper connection structure has a third width in the first horizontal direction and a fourth width in the second horizontal direction,

the first horizontal direction, the second horizontal direction, and the vertical direction being substantially perpendicular to one another, and

the second width is at least twice as large as the first width and the fourth width.

16. The semiconductor die bonding structure of claim 15 , wherein the upper connection structure comprises:

an upper through-via structure including an upper through-via plug, an upper through-via barrier layer surrounding a side surface of the upper through-via plug, and an upper through-via liner layer surrounding a side surface of the upper through-via barrier layer;

an upper bottom bonding pad barrier layer; and

an upper bottom bonding pad body over a lower surface of the upper bottom bonding pad barrier layer, and

the upper bottom bonding pad body and the lower top bonding pad body are directly bonded.

17. The semiconductor die bonding structure of claim 15 , wherein an interface between the lower top bonding dielectric layer and the upper bottom bonding dielectric layer and an interface between the lower top bonding pad structure and the upper connection structure are coplanar.

18. A semiconductor die bonding structure, comprising:

a lower die including a lower top bonding dielectric layer and lower connection structures;

an upper die stacked over the lower die and including an upper bottom bonding dielectric layer and upper connection structures,

wherein:

the lower top bonding dielectric layer and the upper bottom bonding dielectric layer are directly bonded to each other,

each of the lower connection structures and each of the upper connection structures are aligned in a vertical direction, to be directly bonded,

the lower connection structures and the upper connection structures are arranged side by side in a first horizontal direction, respectively;

an upper surface of each of the lower connection structures has a first width in the first horizontal direction and a second width in a second horizontal direction,

a lower surface of each of the upper connection structures has a third width in the first horizontal direction and a fourth width in the second horizontal direction,

the first horizontal direction, the second horizontal direction, and the vertical direction are substantially mutually perpendicular; and

the second width is greater than the first width and the fourth width.