Method of manufacture overlay mark using laser marking process for semiconductor device
View Patent ↗A semiconductor device has a conductive via laterally separated from the semiconductor, an encapsulant between the semiconductor device and the conductive via, and a mark. The mark is formed from characters that are either cross-free characters or else have a overlap count of less than two. In another embodiment the mark is formed using a wobble scan methodology. By forming marks as described, defects from the marking process may be reduced or eliminated.
1. A method of manufacturing a semiconductor device, the method comprising:
encapsulating a first semiconductor device and a through via with an encapsulant, wherein after the encapsulating the encapsulant is located between the first semiconductor device and the through via; and
removing multiple portions of a protective layer over the encapsulant along a circular path with a first plurality of laser beam pulses, wherein each one of the multiple portions has a diameter of less than about 100 μm.
2. The method of claim 1 , wherein the circular path has a constant crossing distance.
3. The method of claim 1 , wherein the circular path has a variable crossing distance.
4. The method of claim 1 , wherein the circular path forms a first line, the first line having a dot width greater than the diameter.
5. The method of claim 1 , further comprising forming a second line with a second plurality of laser beam pulses, the second line having a second dot width that is the same as a second diameter of the second plurality of laser beam pulses.
6. The method of claim 1 , wherein each of the first plurality of laser beam pulses is offset from adjacent ones of the first plurality of laser beam pulses by an offset distance of between about 5 μm and about 100 μm.
7. The method of claim 1 , wherein each of the first plurality of laser beam pulses is offset from adjacent ones of the first plurality of laser beam pulses by an offset distance of between about 5 μm and about 50 μm.
8. A method of manufacturing a semiconductor device, the method comprising:
forming through vias over a protective layer;
attaching a first semiconductor device to the protective layer after the forming the through vias;
placing an encapsulant around the first semiconductor device and the through vias;
forming a redistribution layer over the encapsulant;
removing first portions of the protective layer to expose the through vias; and
removing second portions of the protective layer along a circular path with a first plurality of laser beam pulses, wherein each one of the second portions has a diameter of less than about 100 μm.
9. The method of claim 8 , wherein the circular path forms a line.
10. The method of claim 9 , wherein the removing the second portions forms a line with a dot width greater than the diameter.
11. The method of claim 8 , wherein the circular path comprises a series of arcs, at least two of the series of arcs intersecting each other.
12. The method of claim 8 , wherein the circular path crosses a centerline at regular intervals.
13. The method of claim 8 , wherein the circular path crosses a centerline at irregular intervals.
14. The method of claim 8 , wherein the circular path forms a cross-free character.
15. A method of manufacturing a semiconductor device, the method comprising:
placing a polymer layer onto a carrier substrate;
plating a first through via and a second through via onto the polymer layer;
after the plating, placing a first semiconductor device between the first through via and the second through via;
surrounding the first through via, the second through via, and the first semiconductor device with an encapsulant;
connecting a first redistribution layer to the first through via and the second through via;
after the connecting, removing the carrier substrate to expose the polymer layer;
forming a first opening to a first distance to expose the first through via and the second through via through the polymer layer; and
forming a circular path within the polymer layer to a second distance less than the first distance, wherein the forming the circular path removes portions of the polymer layer with a plurality of laser beam pulses, wherein each one of the portions has a diameter of less than about 100 μm.
16. The method of claim 15 , wherein the circular path forms a line.
17. The method of claim 16 , wherein the line is part of a cross-free character.
18. The method of claim 17 , wherein the line has a dot width between about 80 μm and about 200 μm.
19. The method of claim 15 , wherein the diameter is between about 20 μm and about 50 μm.
20. The method of claim 15 , further comprising recessing the first through via and the second through via.