Chip structure and process for forming the same
View Patent ↗A chip structure comprises a substrate, a first built-up layer, a passivation layer and a second built-up layer. The substrate includes many electric devices placed on a surface of the substrate. The first built-up layer is located on the substrate. The first built-up layer is provided with a first dielectric body and a first interconnection scheme, wherein the first interconnection scheme interlaces inside the first dielectric body and is electrically connected to the electric devices. The first interconnection scheme is constructed from first metal layers and plugs, wherein the neighboring first metal layers are electrically connected through the plugs. The passivation layer is disposed on the first built-up layer and is provided with openings exposing the first interconnection scheme. The second built-up layer is formed on the passivation layer. The second built-up layer is provided with a second dielectric body and a second interconnection scheme, wherein the second interconnection scheme interlaces inside the second dielectric body and is electrically connected to the first interconnection scheme. The second interconnection scheme is constructed from at least one second metal layer and at least one via metal filler, wherein the second metal layer is electrically connected to the via metal filler. The thickness, width, and cross-sectional area of the traces of the second metal layer are respectively larger than those of the first metal layers.
1. A method for fabricating a chip, comprising:
providing a silicon substrate, a transistor in or on said silicon substrate, a first metal layer over said silicon substrate, a second metal layer over said first metal layer and said silicon substrate, a dielectric layer between said first and second metal layers, a conductive pad over said silicon substrate, and a passivation layer over said silicon substrate, said first and second metal layers and said dielectric layer, wherein a first opening in said passivation layer is over a contact point of said conductive pad, and said contact point is at a bottom of said first opening, wherein said first opening has a width between 0.5 and 20 micrometers;
forming a first organic layer on said passivation layer, wherein said first organic layer has a thickness between 1 and 100 micrometers, wherein a second opening in said first organic layer is over said contact point;
forming a third metal layer on a top surface of said first organic layer and on said contact point, wherein said third metal layer comprises titanium;
forming a photoresist layer on said third metal layer, wherein a third opening in said photoresist layer exposes a region of said third metal layer;
electroplating a fourth metal layer on said region, wherein said fourth metal layer comprises copper;
after said electroplating said fourth metal layer, removing said photoresist layer; and
after said removing said photoresist layer, removing said third metal layer not under said fourth metal layer.
2. The method of claim 1 , wherein said forming said third metal layer comprises a sputtering process.
3. The method of claim 1 , wherein said forming said first organic layer comprises forming a polyimide layer on said passivation layer.
4. The method of claim 1 , wherein said forming said first organic layer comprises forming a benzocyclobutene layer on said passivation layer.
5. The method of claim 1 , wherein said forming said first organic layer comprises a spin-on coating process.
6. The method of claim 1 , after said removing said third metal layer not under said fourth metal layer, further comprising forming a second organic layer over said first organic layer and said fourth metal layer.
7. A method for fabricating a chip, comprising:
providing a silicon substrate, a transistor in or on said silicon substrate, a first metal layer over said silicon substrate, a second metal layer over said first metal layer and said silicon substrate, a dielectric layer between said first and second metal layers, a conductive pad over said silicon substrate, and a passivation layer over said silicon substrate, said first and second metal layers and said dielectric layer, wherein a first opening in said passivation layer is over a contact point of said conductive pad, and said contact point is at a bottom of said first opening, wherein said first opening has a width between 0.5 and 20 micrometers;
forming a first organic layer on said passivation layer, wherein said first organic layer has a thickness between 1 and 100 micrometers, wherein a second opening is in said first organic layer is over said contact point;
forming a third metal layer on a top surface of said first organic layer and on said contact point;
forming a photoresist layer on said third metal layer, wherein a third opening in said photoresist layer exposes a region of said third metal layer;
electroplating a fourth metal layer on said region, wherein said fourth metal layer comprises copper;
after said electroplating said fourth metal layer, removing said photoresist layer; and
after said removing said photoresist layer, removing said third metal layer not under said fourth metal layer.
8. The method of claim 7 , wherein said forming said third metal layer comprises a sputtering process.
9. The method of claim 7 , wherein said forming said first organic layer comprises forming a polyimide layer on said passivation layer.
10. The method of claim 7 , wherein said forming said first organic layer comprises forming a benzocyclobutene layer on said passivation layer.
11. The method of claim 7 , wherein said forming said first organic layer comprises a spin-on coating process.
12. The method of claim 7 , after said removing said third metal layer not under said fourth metal layer, further comprising forming a second organic layer over said first organic layer and said fourth metal layer.
13. The method of claim 7 , wherein said forming said third metal layer comprises forming a chromium layer on said top surface and on said contact point.
14. A method for fabricating a chip, comprising:
providing a silicon substrate, a transistor in or on said silicon substrate, a first metal layer over said silicon substrate, a second metal layer over said first metal layer and said silicon substrate, a dielectric layer between said first and second metal layers, a conductive pad over said silicon substrate, and a passivation layer over said silicon substrate, said first and second metal layers and said dielectric layer, wherein a first opening in said passivation layer is over a contact point of said conductive pad, and said contact point is at a bottom of said first opening, wherein said first opening has a width between 0.5 and 20 micrometers;
forming a third metal layer over a top surface of said passivation layer and on said contact point;
forming a photoresist layer on said third metal layer, wherein a second opening in said photoresist layer exposes a region of said third metal layer;
electroplating a fourth metal layer on said region, wherein said fourth metal layer comprises copper;
after said electroplating said fourth metal layer, removing said photoresist layer; and
after said removing said photoresist layer, removing said third metal layer not under said fourth metal layer.
15. The method of claim 14 , wherein said forming said third metal layer comprises a sputtering process.
16. The method of claim 14 , wherein said forming said third metal layer comprises forming a chromium layer over said top surface and on said contact point.
17. The method of claim 14 , wherein said forming said third metal layer comprises forming a titanium-containing layer over said top surface and on said contact point.
18. A method for fabricating a chip, comprising:
providing a silicon substrate, a transistor in or on said silicon substrate, a first metal layer over said silicon substrate, a second metal layer over said first metal layer and said silicon substrate, a dielectric layer between said first and second metal layers, a first conductive pad over said silicon substrate, a second conductive pad over said silicon substrate, and a passivation layer over said silicon substrate, said first and second metal layers and said dielectric layer, wherein a first opening in said passivation layer is over a first contact point of said first conductive pad, and said first contact point is at a bottom of said first opening, wherein said first opening has a width between 0.5 and 20 micrometers, and wherein a second opening in said passivation layer is over a second contact point of said second conductive pad, and said second contact point is at a bottom of said second opening;
forming a first metal interconnect over said passivation layer and on said first and second contact points, wherein said first contact point is connected to said second contact point through said first metal interconnect, wherein said forming said first metal interconnect comprises forming a third metal layer, followed by forming a first photoresist layer on said third metal layer, wherein a third opening in said first photoresist layer exposes a first region of said third metal layer, followed by electroplating a fourth metal layer on said first region, wherein said fourth metal layer comprises copper, followed by removing said first photoresist layer, followed by removing said third metal layer not under said fourth metal layer;
forming a polymer layer over said first metal interconnect and said passivation layer, wherein a fourth opening in said polymer layer is over a third contact point of said first metal interconnect; and
forming a second metal interconnect on said polymer layer and said third contact point, wherein said second metal interconnect is connected to said first contact point through said first metal interconnect, wherein said second metal interconnect is connected to said second contact point through said first metal interconnect, wherein said forming said second metal interconnect comprises forming a fifth metal layer, followed by forming a second photoresist layer on said fifth metal layer, wherein a fifth opening in said second photoresist layer exposes a second region of said fifth metal layer, followed by electroplating a sixth metal layer on said second region, followed by removing said second photoresist layer, followed by removing said fifth metal layer not under said sixth metal layer.
19. The method of claim 18 , wherein said forming said third metal layer comprises a sputtering process.
20. The method of claim 18 , wherein said forming said third metal layer comprises forming a titanium-containing layer.
21. The method of claim 18 , wherein said forming said fifth metal layer comprises forming a titanium-containing layer.
22. The method of claim 18 , wherein said sixth metal layer comprises copper.