Low fabrication cost, fine pitch and high reliability solder bump
First Claim
1. A chip comprising:
- a silicon substrate;
a dielectric layer over said silicon substrate;
a metal pad over said dielectric layer;
a topmost insulating layer of said chip over said dielectric layer, wherein an opening in said topmost insulating layer of said chip exposes said metal pad, and wherein said topmost insulating layer of said chip is a polymer layer; and
a metal bump on said metal pad and on a first top surface of said topmost insulating layer of said chip, wherein said metal bump comprises a metal layer on said metal pad, in said opening and on said first top surface, and a copper pillar on said metal layer, over said opening and over said first top surface, wherein said copper pillar has a height between 10 and 100 micrometers and greater than a transverse dimension of said copper pillar, and wherein said copper pillar has a second top surface higher than said first top surface.
5 Assignments
0 Petitions
Accused Products
Abstract
A barrier layer is deposited over a layer of passivation including in an opening to a contact pad created in the layer of passivation. A column of three layers of metal is formed overlying the barrier layer and aligned with the contact pad and having a diameter that is about equal to the surface of the contact pad. The three metal layers of the column comprise, in succession when proceeding from the layer that is in contact with the barrier layer, a layer of pillar metal, a layer of under bump metal and a layer of solder metal. The layer of pillar metal is reduced in diameter, the barrier layer is selectively removed from the surface of the layer of passivation after which reflowing of the solder metal completes the solder bump of the invention.
221 Citations
48 Claims
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1. A chip comprising:
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a silicon substrate; a dielectric layer over said silicon substrate; a metal pad over said dielectric layer; a topmost insulating layer of said chip over said dielectric layer, wherein an opening in said topmost insulating layer of said chip exposes said metal pad, and wherein said topmost insulating layer of said chip is a polymer layer; and a metal bump on said metal pad and on a first top surface of said topmost insulating layer of said chip, wherein said metal bump comprises a metal layer on said metal pad, in said opening and on said first top surface, and a copper pillar on said metal layer, over said opening and over said first top surface, wherein said copper pillar has a height between 10 and 100 micrometers and greater than a transverse dimension of said copper pillar, and wherein said copper pillar has a second top surface higher than said first top surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. A chip comprising:
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a silicon substrate; a dielectric layer over said silicon substrate; a metal pad over said dielectric layer; a topmost insulating layer of said chip over said dielectric layer, wherein an opening in said topmost insulating layer of said chip exposes said metal pad, and wherein said topmost insulating layer of said chip is a polymer layer; and a metal bump on said metal pad and on a first top surface of said topmost insulating layer of said chip, wherein said metal bump comprises a metal layer on said metal pad, in said opening and on said first top surface, a copper pillar on said metal layer, over said opening and over said first top surface, and a solder over said copper pillar, over said opening and over said first top surface, wherein said solder is connected to said copper pillar, wherein said copper pillar has a height between 10 and 100 micrometers, and wherein said copper pillar has a second top surface higher than said first top surface and a sidewall with a portion not covered by said solder. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A chip comprising:
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a silicon substrate; a dielectric layer over said silicon substrate; a metal layer over said dielectric layer, wherein said metal layer comprises a metal pad and a metal piece separate from said metal pad and neighboring said metal pad; a topmost insulating layer of said chip over said dielectric layer, over said metal pad, over said metal piece and in a gap between said metal pad and said metal piece, wherein an opening in said topmost insulating layer of said chip is over a contact point of said metal pad, and said contact point is at a bottom of said opening, and wherein said topmost insulating layer of said chip is a polymer layer; and a metal bump on said contact point and on a first top surface of said topmost insulating layer of said chip, wherein said metal bump comprises a titanium-containing layer on said contact point, in said opening and on said first top surface, and a copper pillar over said titanium-containing layer, over said opening and over said first top surface, wherein said copper pillar has a height between 10 and 100 micrometers, and wherein said copper pillar has a second top surface higher than said first top surface and a sidewall with a portion not covered by any solder, wherein said first top surface has a first region vertically under said metal bump and vertically over said metal pad and a second region vertically over the middle of said gap, wherein said first region is at a substantially same horizontal level as said second region, and there is no significant step between said first region and said second region. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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31. A chip comprising:
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a silicon substrate; a dielectric layer over said silicon substrate; a metal layer over said dielectric layer, wherein said metal layer comprises a metal pad and a metal piece separate from said metal pad and neighboring said metal pad; a topmost insulating layer of said chip over said dielectric layer, over said metal pad, over said metal piece and in a gap between said metal pad and said metal piece, wherein an opening in said topmost insulating layer of said chip is over a contact point of said metal pad, and said contact point is at a bottom of said opening, and wherein said topmost insulating layer of said chip is a polymer layer; and a metal bump on said contact point and on a first top surface of said topmost insulating layer of said chip, wherein said metal bump comprises an adhesion-barrier layer on said contact point, in said opening and on said first top surface, and a copper pillar over said adhesion-barrier layer, over said opening and over said first top surface, wherein said copper pillar has a height between 10 and 100 micrometers, and wherein said copper pillar has a second top surface higher than said first top surface, wherein said first top surface has a first region vertically under said metal bump and vertically over said metal pad and a second region vertically over the middle of said gap, wherein said first region is at a substantially same horizontal level as said second region. - View Dependent Claims (32, 33, 34, 35, 36, 37)
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38. A chip comprising:
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a semiconductor substrate; a dielectric layer over said semiconductor substrate; a first contact pad over said dielectric layer; a second contact pad over said dielectric layer; a polymer layer over said dielectric layer and said first and second contact pads and between said first and second contact pads, wherein a first opening in said polymer layer is over a first contact point of said first contact pad, and wherein a second opening in said polymer layer is over a second contact point of said second contact pad; a first metal bump on said first contact point and on a top surface of said polymer layer, wherein said first metal bump is connected to said first contact point through said first opening; and a second metal bump on said second contact point and on said top surface, wherein said second metal bump is connected to said second contact point through said second opening, wherein each of said first and second metal bumps comprises a metal layer on said first or second contact point, on a sidewall of said first or second opening and on said top surface, and a copper pillar on said metal layer, over said first or second opening and over said top surface, wherein said copper pillar has a height between 10 and 100 micrometers, wherein said copper pillar has a sidewall exposed, wherein said top surface between said first and second metal bumps is substantially coplanar. - View Dependent Claims (39, 40, 41, 42, 43)
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44. A chip comprising:
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a semiconductor substrate; a dielectric layer over said semiconductor substrate; a metallization structure over said dielectric layer, wherein said metallization structure comprises a copper layer; a polymer layer over said dielectric layer and said metallization structure, wherein a first opening in said polymer layer is over a first contact point of said metallization structure, and wherein a second opening in said polymer layer is over a second contact point of said metallization structure, wherein said polymer layer is between said first and second contact points; a first metal bump on said first contact point and a top surface of said polymer layer, wherein said first metal bump is connected to said first contact point through said first opening; and a second metal bump on said second contact point and said top surface, wherein said second metal bump is connected to said second contact point through said second opening, wherein each of said first and second metal bumps comprises a metal layer on said first or second contact point, a sidewall of said first or second opening and said top surface, and a copper pillar on said metal layer and over said first or second opening and said top surface, wherein said copper pillar has a height between 10 and 100 micrometers, wherein said copper pillar has a sidewall exposed, wherein said top surface between said first and second metal bumps is substantially coplanar. - View Dependent Claims (45, 46, 47, 48)
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Specification