Stacked semiconductor structure and method
A device comprises a first chip comprising a first connection pad embedded in a first dielectric layer and a first bonding pad embedded in the first dielectric layer, wherein the first bonding pad comprises a first portion and a second portion, the second portion being in contact with the first connection pad and a second chip comprising a second bonding pad embedded in a second dielectric layer of the second chip, wherein the first chip and the second chip are face-to-face bonded together through the first bonding pad the second bonding pad.
1. A device comprising:
a first chip comprising:
a first connection pad embedded in a first dielectric layer; and
a first bonding pad embedded in the first dielectric layer, wherein the first bonding pad comprises a first portion and a second portion, the second portion being in contact with the first connection pad; and
a second chip comprising:
a second connection pad on a non-bonding side of the second chip, wherein a top surface of the second connection pad is lower than a backside of a substrate of the second chip; and
a second bonding pad embedded in a second dielectric layer of the second chip, wherein the first chip and the second chip are face-to-face bonded together through the first bonding pad the second bonding pad.
2. The device of claim 1 , wherein:
a width of the first connection pad is greater than a width of the second portion of the first bonding pad; and
a width of the first portion of the first bonding pad is greater than the width of the second portion of the first bonding pad.
3. The device of claim 1 , wherein:
a width of the second bonding pad is greater than a width of the first portion of the first bonding pad.
4. The device of claim 1 , further comprising:
a homogeneous layer between the first bonding pad and the second bonding pad, wherein the homogeneous layer is formed through an inter-diffusion process between the first bonding pad and the second bonding pad.
5. The device of claim 1 , wherein:
the second portion of the first bonding pad is a connector between the first portion of the first bonding pad and the first connection pad.
6. The device of claim 5 , wherein:
the connector is formed of tungsten.
7. A device comprising:
a first chip comprising:
a first substrate;
a first interconnect structure over the first substrate;
a first connection pad embedded in a first dielectric layer over the first interconnect structure;
a first bonding pad embedded in the first dielectric layer; and
a connector between the first connection pad and the first bonding pad; and
a second chip comprising:
a second substrate;
a second interconnect structure over the second substrate; and
a second bonding pad embedded in a second dielectric layer of the second chip, wherein the first chip and the second chip are face-to-face bonded together through the first bonding pad and the second bonding pad, and wherein the first interconnect structure and the second interconnect structure are face-to-face bonded together.
8. The device of claim 7 , wherein:
a width of the first bonding pad is greater than a width of the connector; and
a width of the first connection pad is greater than the width of the connector.
9. The device of claim 7 , further comprising:
a homogenous layer between the first bonding pad and the second bonding pad.
10. The device of claim 7 , wherein:
the connector is in direct contact with the first bonding pad and the first connection pad.
11. The device of claim 7 , wherein:
a width of the second bonding pad is greater than a width of the first bonding pad.
12. A device comprising:
a first chip comprising:
a first connection pad embedded in a first dielectric layer; and
a first bonding pad embedded in the first dielectric layer, wherein the first bonding pad comprises a first portion and a second portion having different widths; and
a second chip comprising a second bonding pad embedded in a second dielectric layer of the second chip, wherein the first chip and the second chip are face-to-face bonded together through the first bonding pad and the second bonding pad.
13. The device of claim 12 , wherein:
a width of the first portion is greater than a width of the second portion.
14. The device of claim 12 , wherein:
the second portion of the first bonding pad is between the first portion of the first bonding pad and the first connection pad.
15. The device of claim 12 , wherein:
the first connection pad is formed of aluminum;
the second portion of the first bonding pad is a connector formed of tungsten;
the first portion of the first bonding pad is formed of copper; and
the second bonding pad is formed of copper.
16. The device of claim 12 , further comprising:
a second connection pad and a third connection pad on a non-bonding side of the second chip.
17. The device of claim 16 , wherein:
the second connection pad and the third connection pad are adjacent to sidewalls of a substrate of the second chip and on opposite sides of the substrate.
18. The device of claim 12 , further comprising:
a homogenous layer between the first bonding pad and the second bonding pad.
19. The device of claim 1 , wherein the second chip is mounted to a substrate, wherein the second connection pad is wire bonded to a contact on the substrate.
20. The device of claim 7 , wherein the first dielectric layer is directly bonded to the second dielectric layer.