Semiconductor packages and methods for forming the same

1. A method for forming a semiconductor package, comprising:

providing a first integrated circuit die having a first circuit design on a substrate;

providing a second integrated circuit die having a second circuit design on the substrate, wherein the first and second integrated circuit dies are separated from each other by a scribe line;

forming a first interconnect structure on a first surface of the first integrated circuit die;

forming a second interconnect structure on a first surface of the second integrated circuit die;

extending a power rail from a second surface of the first integrated circuit die to a first side of a source/drain (S/D) feature;

forming one or more power lines through an entire thickness of the first and second integrated circuit dies, respectively;

forming a third interconnect structure on the second surface of the first integrated circuit die; and

forming a fourth interconnect structure on the second surface of the second integrated circuit die.

2. The method of claim 1 , further comprising:

forming a source/drain contact on a second side of the S/D feature, the second side being opposite to the first side of the S/D feature.

3. The method of claim 1 , further comprising:

forming an edge interconnect feature having a first end connected to a conductive feature in the first interconnect structure and a second end connected to a conductive feature in the second interconnect structure, wherein the edge interconnect feature extends through the scribe line.

4. The method of claim 1 , wherein at least one power line electrically connects the third interconnect structure to the first interconnect structure, and at least one power line electrically connects the fourth interconnect structures to the second interconnect structure.

5. The method of claim 4 , further comprising:

forming a third integrated circuit die having a third circuit design;

forming a fifth interconnect structure on the third integrated circuit die; and

bonding the fifth interconnect structure to the third and fourth interconnect structures.

6. The method of claim 5 , further comprising:

attaching the first and second interconnect structures to a redistribution layer, wherein a portion of the redistribution is in contact with the scribe line.

7. The method of claim 6 , further comprising:

forming electrically conductive sealing rings in the first and second interconnect structures, wherein the electrically conductive sealing rings extend in a seal region located between the first and second integrated circuit dies and the scribe line.

8. The method of claim 6 , wherein the electrically conductive sealing rings are electrically grounded.

9. A method for forming a semiconductor package, comprising:

providing a first integrated circuit die having a first circuit design on a substrate;

providing a second integrated circuit die having a second circuit design on the substrate, wherein the first and second integrated circuit dies are separated from each other by a scribe line;

forming a first interconnect structure on a first surface of the first integrated circuit die;

forming a second interconnect structure on a first surface of the second integrated circuit die;

extending a power rail from a second surface of the first integrated circuit die to a first side of a source/drain (S/D) feature;

forming a third interconnect structure on the second surface of the first integrated circuit die, the third interconnect structure being in contact with the power rail;

forming a fourth interconnect structure on the second surface of the second integrated circuit die, the fourth interconnect structure being in contact with the power rail;

forming a third integrated circuit die having a third circuit design;

forming a fifth interconnect structure on the third integrated circuit die;

bonding the fifth interconnect structure to the third and fourth interconnect structures; and

attaching the first and second interconnect structures to a redistribution layer.

10. The method of claim 9 , further comprising:

forming one or more power lines through an entire thickness of the first and second integrated circuit dies, respectively.

11. The method of claim 9 , further comprising:

forming a source/drain contact on a second side of the S/D feature, the second side being opposite to the first side of the S/D feature.

12. The method of claim 9 , further comprising:

forming an edge interconnect feature having a first end connected to a conductive feature in the first interconnect structure and a second end connected to a conductive feature in the second interconnect structure, wherein the edge interconnect feature extends through the scribe line.

13. The method of claim 12 , wherein the one or more power lines are formed such that at least one power line electrically connects the third interconnect structure to the first interconnect structure, and at least one power line electrically connects the fourth interconnect structures to the second interconnect structure.

14. The method of claim 12 , wherein the edge interconnect feature is extended through the scribe line.

15. The method of claim 14 , wherein a portion of the redistribution is in contact with the scribe line.

16. The method of claim 15 , further comprising:

forming electrically conductive sealing rings in the first and second interconnect structures, wherein the electrically conductive sealing rings extend in a seal region located between the first and second integrated circuit dies and the scribe line.

17. The method of claim 16 , wherein the electrically conductive sealing rings are electrically grounded.

18. A method for forming a semiconductor package, comprising:

providing a first integrated circuit die and a second integrated circuit die on a substrate, wherein each first and second integrated circuit die comprises a device layer and an interconnect structure formed over the device layer, and a first side of a source/drain (S/D) feature in the device layer of the first and second integrated circuit dies is coupled to a S/D contact;

bonding the interconnect structure of the first and second integrated circuit dies to a carrier substrate so that a back side of the device layer of the first and second integrated circuit dies is facing up;

providing a backside power rail to a back side of the S/D feature in the device layer of the first and second integrated circuit dies;

forming a backside interconnect structure on the back side of the device layer of the first and second integrated circuit dies so that the backside interconnect structure is in contact with the backside power rail;

providing a third integrated circuit die comprising a device layer and an interconnect structure;

bonding the interconnect structure of the third integrated circuit die to the interconnect structure of the first and second integrated circuit dies;

removing the carrier substrate; and

attaching the interconnect structures of the first and second integrated circuit dies to a redistribution layer.

19. The method of claim 18 , further comprising:

prior to bonding the interconnect structure of the first and second integrated circuit dies to the carrier substrate, connecting the first and second integrated circuit dies by extending an edge interconnect feature from the interconnect structure of the first integrated circuit die to the interconnect structure of the second integrated circuit die.

20. The method of claim 19 , wherein a portion of the edge interconnect feature is extended through a scribe line separating the first integrated circuit die and the second integrated circuit die.