Packaged semiconductor device with a molding compound and a method of forming the same
The mechanisms of forming a molding compound on a semiconductor device substrate to enable fan-out structures in wafer-level packaging (WLP) are provided. The mechanisms involve covering portions of surfaces of an insulating layer surrounding a contact pad. The mechanisms improve reliability of the package and process control of the packaging process. The mechanisms also reduce the risk of interfacial delamination, and excessive outgassing of the insulating layer during subsequent processing. The mechanisms further improve planarization end-point. By utilizing a protective layer between the contact pad and the insulating layer, copper out-diffusion can be reduced and the adhesion between the contact pad and the insulating layer may also be improved.
1. A packaged semiconductor device, comprising:
a contact pad on a semiconductor die;
an insulating layer surrounding the contact pad, wherein the insulating layer surrounding the contact pad has a thin portion and a thick portion;
a molding compound surrounding the insulating layer, wherein the molding compound comes in contact with two adjacent and non-linear surfaces of the insulating layer, and a top surface of the molding compound is co-planar with a top surface of the thick portion of the insulating layer; and
a wiring layer electrically connected to the contact pad, wherein the wiring layer extends beyond a boundary of the semiconductor die.
2. The package semiconductor device of claim 1 , wherein the wiring layer is disposed on and physically connects to the contact pad.
3. The package semiconductor device of claim 1 , wherein the thin portion has a thickness in a range from about 1 μm to about 30 μm.
4. The package semiconductor device of claim 1 , wherein a protective layer is between the contact pad and the insulating layer.
5. The package semiconductor device of claim 4 , wherein the protective layer is a copper diffusion barrier.
6. The package semiconductor device of claim 4 , wherein the protective layer has a thickness in a range from about 50 μm to about 2 μm.
7. The package semiconductor device of claim 4 , wherein the protective layer is also between the insulating layer and another insulating layer underneath.
8. The package semiconductor device of claim 4 , wherein the protective layer is a dielectric material and includes a material selected from a group consisting of SiN, SiC, SiCN, SiCO, TEOS, SiO 2 , or a low-k dielectric.
9. The package semiconductor device of claim 8 , wherein the dielectric material also improves adhesion between the contact pad and the insulating layer.
10. The package semiconductor device of claim 4 , wherein the protective layer is a conductive material and is made of a material selected from a group consisting of Ta, TaN, Ti, TiN, Co, and Mn.
11. The package semiconductor device of claim 1 , wherein the contact pad is a copper post and has an under bump metallization layer underneath.
12. The packages semiconductor device of claim 1 , wherein a thickness of the contact pad is greater than a thickness of the insulating layer.
13. A packaged semiconductor device, comprising:
a contact pad on a semiconductor die;
an insulating layer surrounding sidewalls of the contact pad;
a protective layer, wherein the protective layer is between the sidewalls of the contact pad and the insulating layer; and
a molding compound surrounding the insulating layer, wherein the molding compound comes in contact with two adjacent and non-linear surfaces of the insulating layer, and the insulating layer separates the molding compound from an entirety of the semiconductor die.
14. A packaged semiconductor device, comprising:
a contact pad on a semiconductor die;
an insulating layer surrounding the contact pad; and
a molding compound surrounding the insulating layer, wherein the molding compound is separated from the contact pad, and the molding compound contacts a first surface of the insulating layer, a second surface of the insulating layer, and a third surface of the insulating layer, and the first surface is not parallel with the second surface, the third surface is substantially parallel to the first surface, and the second surface is between the third surface and the first surface.
15. The packaged semiconductor device of claim 14 , further comprising a protective layer between sidewalls of the contact pad and the insulating layer.
16. The packaged semiconductor device of claim 15 , further comprising a second insulating layer under the insulating layer, wherein the protective layer is between the insulating layer and the second insulating layer.
17. The packaged semiconductor device of claim 14 , wherein a top surface of the contact pad is positioned farther from the semiconductor die than the second surface.
18. The packaged semiconductor device of claim 14 , wherein a top surface of the molding compound is coplanar with a top surface of the contact pad.
19. The package semiconductor device of claim 14 , wherein the insulating layer comprises:
a top portion positioned to separate the molding compound from the contact pad in a direction parallel to a top surface of the contact pad by a first distance; and
a lower portion positioned to separate the molding compound from the contact pad in the direction parallel to the top surface of the contact pad by a second distance, wherein the second distance is greater than the first distance.
20. The package semiconductor device of claim 14 , wherein a top of the third surface is co-planar with a top surface of the molding compound.