Semiconductor packages and methods of fabricating the same
Provided are a semiconductor package and a method of fabricating the same. In one embodiment, to fabricate a semiconductor package, a wafer having semiconductor chips fabricated therein is provided. A heat sink layer is formed over the wafer. The heat sink layer contacts top surfaces of the semiconductor chips. Thereafter, the plurality of semiconductor chips are singulated from the wafer.
1. A method of fabricating a semiconductor stack package, the method comprising:
providing a plurality of separated second semiconductor chips over a wafer including a plurality of first semiconductor chips, wherein the plurality of separated second semiconductor chips are disposed over corresponding ones of the plurality of first semiconductor chips;
forming a heat sink layer that contacts top surfaces of the plurality of separated second semiconductor chips; and
thereafter, singulating the plurality of first semiconductor chips from the wafer to form a plurality of chip stacks where the plurality of separated second semiconductor chips are stacked on the corresponding ones of the plurality of first semiconductor chips that are singulated.
2. The method of claim 1 , wherein the heat sink layer does not contain a polymer.
3. The method of claim 1 , which further comprises:
forming a molding layer using a compression mold to cover the plurality of first and second semiconductor chips; and
exposing top surfaces of the plurality of separated second semiconductor chips by removing at least a portion of the molding layer.
4. The method of claim 3 , wherein exposing top surfaces of the plurality of separated second semiconductor chips comprises simultaneously grinding the molding layer and the plurality of separated second semiconductor chips.
5. The method of claim 4 , wherein exposing the top surfaces of the plurality of separated second semiconductor chips comprises exposing substantially entire top surfaces of the plurality of separated second semiconductor chips.
6. The method of claim 1 , wherein the heat sink layer comprises a first metal layer and a second metal layer formed on the first metal layer.
7. The method of claim 6 , wherein the first metal layer comprises a material chosen from Ti, Cr, Ta, Ni, TiW, combinations thereof, or alloys thereof, wherein the second metal layer comprises Cu.
8. The method of claim 7 , wherein the heat sink layer further comprises a third metal layer overlying the second metal layer, and wherein the third metal layer comprises Ni or Ni/Au.
9. The method of claim 6 , wherein the first metal layer is formed in a substantially continuous layer across the width of the second semiconductor chip, and wherein the second metal layer is formed having gaps between segments of the second metal layer along the width of the second semiconductor chip.
10. The method of claim 6 , wherein the second metal layer is formed in a substantially continuous layer across the width of the second semiconductor chip, and wherein the second metal layer is formed having gaps between segments of the second metal layer overlying the molding layer.
11. The method of claim 1 , further comprising attaching the plurality of first semiconductor chips on a carrier with an adhesive layer interposed therebetween.
12. The method of claim 1 , wherein forming the heat sink layer comprises using a technique chosen from plating, chemical vapor deposition, physical vapor deposition, atomic layer deposition (ALD) or soft lithography.
13. The method of claim 1 , wherein forming the heat sink layer comprises forming a seed layer and forming a layer of nano-tube formed on the seed layer.
14. The method of claim 1 , further comprising:
forming a molding layer using a compression mold to cover the first and second semiconductor chips; and
planarizing the molding layer and exposing substantially the entire top surfaces of the plurality of second semiconductor chips,
wherein the heat sink layer is in contact with a top surface and a sidewall of the planarized molding layer.
15. The method of claim 14 , further comprising providing a package substrate having a through via extending therethrough, wherein the first and second semiconductor chips are disposed over the package substrate, wherein the heat sink layer is in contact with a top surface of the package substrate, and wherein the through via is coupled to a portion of the heat sink layer where the heat sink layer is in contact with the top surface of the package substrate.
16. A method of forming a semiconductor package, the method comprising:
providing a second semiconductor chip overlying a first semiconductor chip having through vias extending through at least a portion thereof;
forming a molding layer covering the first and second semiconductor chips;
planarizing the molding layer until a top surface of the second semiconductor chip is exposed such that a top surface of the planarized molding layer is substantially coplanar with the top surface of the second semiconductor chip; and
forming a heat sink layer that directly contacts the exposed top surface of the second semiconductor chip and the top surface of the planarized molding layer.
17. The method of claim 16 , wherein, in cross-sectional view, the heat sink layer extends in a straight line across the planarized molding layer and the top surface of the second semiconductor chip at an interface thereof.
18. The method of claim 16 , wherein the second semiconductor chips have through vias extending therethrough and directly coupled to the heat sink layer.