Semiconductor package and method
In an embodiment, a device includes: a first redistribution structure including a first dielectric layer; a die adhered to a first side of the first redistribution structure; an encapsulant laterally encapsulating the die, the encapsulant being bonded to the first dielectric layer with first covalent bonds; a through via extending through the encapsulant; and first conductive connectors electrically connected to a second side of the first redistribution structure, a subset of the first conductive connectors overlapping an interface of the encapsulant and the die.
1. A method comprising:
depositing a seed layer on a dielectric layer;
etching the seed layer, residual metal of the seed layer buried in the dielectric layer after etching the seed layer;
performing a first treatment process on the dielectric layer to simultaneously thin the dielectric layer and hydroxylate a surface of the dielectric layer, the residual metal of the seed layer being exposed by the thinning of the dielectric layer;
performing a second treatment process to remove the residual metal of the seed layer exposed by the thinning of the dielectric layer;
adhering an integrated circuit die to the surface of the dielectric layer;
dispensing an encapsulant on the surface of the dielectric layer, the encapsulant laterally surrounding the integrated circuit die; and
forming covalent bonds between the dielectric layer and the encapsulant.
2. The method of claim 1 , wherein the seed layer is deposited by sputtering.
3. The method of claim 1 , wherein forming the covalent bonds comprises curing the encapsulant.
4. The method of claim 1 , wherein the first treatment process is a dry etch performed with oxygen while creating a plasma.
5. The method of claim 1 , wherein the second treatment process is a wet etch performed with hydrofluoric acid.
6. The method of claim 1 further comprising:
plating a conductive material on the seed layer, wherein portions of the seed layer and the conductive material remaining after etching the seed layer form a through via.
7. The method of claim 1 , wherein hydroxylating the surface of the dielectric layer forms hydroxyl groups dangling from the surface of the dielectric layer, the encapsulant comprises a nucleophile, and forming the covalent bonds comprises reacting the hydroxyl groups and the nucleophile.
8. The method of claim 1 , wherein the second treatment process does not thin the dielectric layer.
9. A method comprising:
sputtering a seed layer onto a dielectric layer, a first portion of the seed layer disposed on a surface of the dielectric layer, a second portion of the seed layer implanted into the dielectric layer;
removing the first portion of the seed layer by etching the first portion of the seed layer;
after removing the first portion of the seed layer, removing the second portion of the seed layer and forming hydroxyl groups dangling from the surface of the dielectric layer by treating the surface of the dielectric layer;
dispensing an encapsulant on the surface of the dielectric layer, the encapsulant comprising a nucleophile; and
curing the encapsulant to form covalent bonds between the nucleophile and the hydroxyl groups.
10. The method of claim 9 , wherein treating the surface of the dielectric layer comprises:
plasma treating the dielectric layer with oxygen; and
after plasma treating the dielectric layer, etching the second portion of the seed layer with hydrofluoric acid.
11. The method of claim 10 , wherein the plasma treating the dielectric layer reduces a thickness of the dielectric layer, and etching the second portion of the seed layer does not reduce the thickness of the dielectric layer.
12. The method of claim 9 further comprising:
forming pits in the surface of the dielectric layer, the second portion of the seed layer implanted into the pits.
13. The method of claim 9 further comprising:
before removing the first portion of the seed layer, plating a conductive material on the seed layer to form a through via.
14. A method comprising:
plating a through via through a first dielectric layer with a seed layer;
etching exposed portions of the seed layer, residual portions of the seed layer remaining buried in the first dielectric layer;
after etching the exposed portions of the seed layer, etching the first dielectric layer to thin the first dielectric layer and to hydroxylate a first surface of the first dielectric layer;
after etching the first dielectric layer, etching the residual portions of the seed layer to remove the residual portions of the seed layer from the first dielectric layer;
adhering an integrated circuit die to the first surface of the first dielectric layer; and
bonding an encapsulant to the first surface of the first dielectric layer with first covalent bonds, the encapsulant laterally encapsulating the integrated circuit die and the through via.
15. The method of claim 14 , wherein etching the residual portions of the seed layer does not thin the first dielectric layer.
16. The method of claim 14 , wherein etching the first dielectric layer comprises dry etching the first dielectric layer with oxygen while creating a plasma.
17. The method of claim 14 , wherein etching the residual portions of the seed layer comprises wet etching the residual portions of the seed layer with hydrofluoric acid.
18. The method of claim 14 , wherein hydroxylating the first surface of the first dielectric layer forms hydroxyl groups dangling from the first surface of the first dielectric layer, and bonding the encapsulant to the first surface of the first dielectric layer comprises:
dispensing the encapsulant on the first surface of the first dielectric layer, the encapsulant comprising a nucleophile; and
curing the encapsulant to form the first covalent bonds between the nucleophile and the hydroxyl groups.
19. The method of claim 14 , wherein adhering the integrated circuit die to the first surface of the first dielectric layer comprises:
bonding an adhesive to the first surface of the first dielectric layer with second covalent bonds, the adhesive adhering the integrated circuit die to the first surface of the first dielectric layer.
20. The method of claim 19 , wherein hydroxylating the first surface of the first dielectric layer forms hydroxyl groups dangling from the first surface of the first dielectric layer, and bonding the adhesive to the first surface of the first dielectric layer comprises:
dispensing the adhesive on the first surface of the first dielectric layer, the adhesive comprising a nucleophile; and
curing the adhesive to form the second covalent bonds between the nucleophile and the hydroxyl groups.