Semiconductor chip with passivation layer comprising metal interconnect and contact pads
View Patent ↗The invention provides a semiconductor chip comprising a semiconductor substrate comprising a MOS device, an interconnecting structure over said semiconductor substrate, and a metal bump over said MOS device, wherein said metal bump has more than 50 percent by weight of gold and has a height of between 8 and 50 microns.
1. A semiconductor chip comprising:
a silicon substrate;
a MOS device in or on said silicon substrate;
a first metal layer over said silicon substrate;
a dielectric layer on said first metal layer and over said silicon substrate;
a second metal layer on said dielectric layer;
a passivation layer on said second metal layer and over said dielectric layer, wherein a first opening in said passivation layer is over a first contact pad of said second metal layer, a second opening in said passivation layer is over a second contact pad of said second metal layer, and a third opening in said passivation layer is over a third contact pad of said second metal layer, wherein said first, second and third contact pads are aligned in a first line, wherein said second contact pad is between said first and third contact pads, and wherein said passivation layer comprises a nitride layer;
a patterned metal layer on said first, second and third contact pads and over said passivation layer, wherein said patterned metal layer comprises a fourth contact pad on said first contact pad, wherein said fourth contact pad is connected to said first contact pad through said first opening, wherein said patterned metal layer comprises a fifth contact pad connected to said second contact pad through said second opening, wherein the position of said fifth contact pad from a top perspective view is different from that of said second contact pad, and wherein said patterned metal layer comprises a sixth contact pad on said third contact pad, wherein said sixth contact pad is connected to said third contact pad through said third opening;
a first metal bump on said fourth contact pad and over said first contact pad;
a second metal bump on said fifth contact pad, wherein the position of said second metal bump from said top perspective view is different from that of said second contact pad; and
a third metal bump on said sixth contact pad and over said third contact pad, wherein said first and third metal bumps are aligned in a second line parallel with said first line, and wherein said third metal bump comprises a gold layer, having more than 50 percent by weight of gold and having a height between 8 and 50 micrometers, over said third and sixth contact pads.
2. The semiconductor chip of claim 1 further comprising a polymer layer between said patterned metal layer and said passivation layer.
3. The semiconductor chip of claim 2 , wherein said polymer layer comprises polyimide.
4. The semiconductor chip of claim 2 , wherein said polymer layer comprises benzocyclobutene (BCB).
5. The semiconductor chip of claim 2 , wherein said polymer layer has a thickness between 1 and 30 micrometers.
6. The semiconductor chip of claim 1 , wherein said nitride layer has a thickness between 0.2 and 1 micrometer.
7. The semiconductor chip of claim 1 , wherein said gold layer has more than 90 percent by weight of gold.
8. The semiconductor chip of claim 1 , wherein said height is between 10 and 30 micrometers.
9. The semiconductor chip of claim 1 , wherein said first and second metal layers comprise aluminum.
10. The semiconductor chip of claim 1 , wherein said first and second metal layers comprise electroplated copper.
11. A chip comprising:
a silicon substrate;
a MOS device in or on said silicon substrate;
a first metal layer over said silicon substrate;
a dielectric layer on said first metal layer and over said silicon substrate;
a second metal layer on said dielectric layer;
a passivation layer on said second metal layer and over said dielectric layer, wherein a first opening in said passivation layer is over a first contact pad of said second metal layer, a second opening in said passivation layer is over a second contact pad of said second metal layer, and a third opening in said passivation layer is over a third contact pad of said second metal layer, wherein said first, second and third contact pads are aligned in a first line, wherein said second contact pad is between said first and third contact pads, and wherein said passivation layer comprises a nitride layer;
a patterned metal layer on said first, second and third contact pads and over said passivation layer, wherein said patterned metal layer comprises a first metal trace over said passivation layer, wherein said first metal trace is connected to said first contact pad through said first opening, and wherein said patterned metal layer comprises a fourth contact pad connected to said first contact pad through said first metal trace, wherein the position of said fourth contact pad from a top perspective view is different from that of said first contact pad, wherein said patterned metal layer comprises a second metal trace over said passivation layer, wherein said second metal trace is connected to said second contact pad through said second opening, and wherein said patterned metal layer comprises a fifth contact pad connected to said second contact pad through said second metal trace, wherein the position of said fifth contact pad from said top perspective view is different from that of said second contact pad, and wherein said patterned metal layer comprises a third metal trace over said passivation layer, wherein said third metal trace is connected to said third contact pad through said third opening, and wherein said patterned metal layer comprises a sixth contact pad connected to said third contact pad through said third metal trace, wherein the position of said sixth contact pad from said top perspective view is different from that of said third contact pad, wherein said second metal trace passes through a gap between said fourth and sixth contact pads;
a first metal bump on said fourth contact pad, wherein the position of said first metal bump from said top perspective view is different from that of said first contact pad;
a second metal bump on said fifth contact pad, wherein the position of said second metal bump from said top perspective view is different from that of said second contact pad; and
a third metal bump on said sixth contact pad, wherein said first and third metal bumps are aligned in a second line parallel with said first line, wherein the position of said third metal bump from said top perspective view is different from that of said third contact pad, and wherein said third metal bump comprises a gold layer, having more than 50 percent by weight of gold and having a height between 8 and 50 micrometers, over said sixth contact pad.
12. The chip of claim 11 , wherein said gold layer has more than 90 percent by weight of gold.
13. The chip of claim 11 further comprising a polymer layer between said patterned metal layer and said passivation layer.
14. The chip of claim 13 , wherein said polymer layer has a thickness between 1 and 30 micrometers.
15. The chip of claim 13 , wherein said polymer layer comprises benzocyclobutene (BCB).
16. The chip of claim 13 , wherein said polymer layer comprises polyimide.
17. The chip of claim 11 , wherein said height is between 10 and 30 micrometers.
18. The chip of claim 11 , wherein said first and second metal layers comprise electroplated copper.
19. The chip of claim 11 , wherein said first and second metal layers comprise aluminum.
20. The chip of claim 11 , wherein said passivation layer further comprises an oxide layer under said nitride layer.