Robust pillar structure for semicondcutor device contacts
Methods and systems for a robust pillar structure for a semiconductor device contacts are disclosed, and may include processing a semiconductor wafer comprising one or more metal pads, wherein the processing may comprise: forming a second metal contact on the one or more metal pads; forming a pillar on the second metal contact, and forming a solder bump on the second metal contact and the pillar, wherein the pillar extends into the solder bump. The second metal contact may comprise a stepped mushroom shaped bump, a sloped mushroom shaped bump, a cylindrical post, and/or a redistribution layer. The semiconductor wafer may comprise silicon. A solder brace layer may be formed around the second metal contact. The second metal contact may be tapered down to a smaller area at the one or more metal pads on the semiconductor wafer. A seed layer may be formed between the second metal contact and the one or more metal pads on the semiconductor wafer. The pillar may comprise copper.
1. A device comprising:
a substrate;
a metal pad on a top surface of the substrate;
a conductive layer electrically coupled to the metal pad;
a pillar electrically coupled to the metal pad via the conductive layer;
a covering bump over the pillar and a portion of the conductive layer such that the covering bump contacts the pillar and a horizontal portion of an upper surface of the conductive layer; and
a bracing layer that contacts a lower portion of the covering bump,
wherein the pillar comprises a first portion with a first width and a second portion with a second width, and the first width is larger than the second width, wherein the second portion is below the first portion.
2. The device of claim 1 , wherein the conductive layer is concave shaped in a region of the conductive layer that contacts the metal pad.
3. The device of claim 1 , wherein the conductive layer comprises multiple layers, and a lowest of the multiple layers comprises a titanium/tungsten layer.
4. A device comprising:
a substrate;
a metal pad on a top surface of the substrate;
a conductive layer electrically coupled to the metal pad;
a pillar electrically coupled to the metal pad via the conductive layer;
a covering bump over the pillar and a portion of the conductive layer such that the covering bump contacts the pillar and a horizontal portion of an upper surface of the conductive layer;
a bracing layer that contacts a lower portion of the covering bump; and
a passivation layer on a portion of the top surface of the substrate.
5. The device of claim 4 , wherein the pillar is substantially a trapezoid with a top of the trapezoid wider than a bottom of the trapezoid.
6. The device of claim 4 , comprising a first dielectric layer, a portion of which is on a top surface of the passivation layer, and wherein a portion of the conductive layer is on the first dielectric layer.
7. The device of claim 6 , comprising a second dielectric layer on a top surface of the first dielectric layer, wherein the bracing layer is on a portion of a top surface of the second dielectric layer.
8. The device of claim 4 , wherein the pillar is substantially a trapezoid with a top of the trapezoid wider than a bottom of the trapezoid.
9. The device of claim 4 , wherein the pillar comprises a first portion with a first width and a second portion with a second width, the first width is larger than the second width, and the first portion is closer to a top of the pillar than the second portion.
10. The device of claim 4 , wherein the conductive layer is concave shaped in region of the conductive layer that contacts the metal pad.
11. The device of claim 4 , wherein the conductive layer comprises multiple layers, and a lowest of the multiple layers comprises a titanium/tungsten layer.
12. A device comprising:
a substrate;
a metal pad on a top surface of the substrate;
a conductive layer electrically coupled to the metal pad;
a pillar electrically coupled to the metal pad via the conductive layer;
a covering bump over the pillar and a portion of the conductive layer such that the covering bump contacts the pillar and a horizontal portion of an upper surface of the conductive layer; and
a bracing layer that contacts a lower portion of the covering bump;
wherein a sidewall of the pillar covered by the covering bump is at an acute angle relative to the conductive layer.
13. The device of claim 12 , wherein the pillar is substantially a trapezoid with a top of the trapezoid wider than a bottom of the trapezoid.
14. The device of claim 12 , wherein the pillar comprises a first portion with a first width and a second portion with a second width, the first width is larger than the second width, and the first portion is closer to a top of the pillar than the second portion.
15. The device of claim 12 , wherein the conductive layer is concave shaped in a region of the conductive layer that contacts the metal pad.
16. The device of claim 12 , wherein the conductive layer comprises multiple layers, and a lowest of the multiple layers comprises a titanium/tungsten layer.
17. A device comprising:
a substrate;
a passivation layer on a portion of a top surface of the substrate;
a metal pad on the top surface of the substrate;
a conductive layer electrically coupled to the metal pad;
a bump anchor electrically coupled to the metal pad via the conductive layer;
a covering bump over bump anchor such that the covering bump contacts the bump anchor;
a bracing layer that contacts a lower portion of the covering bump;
a first dielectric layer, a portion of which is on a top surface of the passivation layer, and wherein a portion of the conductive layer is on the first dielectric layer; and
a second dielectric layer on a top surface of the first dielectric layer, wherein the bracing layer is on a portion of a top surface of the second dielectric layer.
18. The device of claim 17 , wherein the bracing layer is at least four times thicker than the first dielectric layer.
19. The device of claim 17 , wherein the bump anchor is substantially a trapezoid with a top of the trapezoid wider than a bottom of the trapezoid.
20. The device of claim 17 , wherein the bump anchor comprises a first portion with a first width and a second portion with a second width, the first width is larger than the second width, and the first portion is closer to a top of the bump anchor than the second portion.
21. The device of claim 17 , wherein the conductive layer is concave shaped in a region of the conductive layer that contacts the metal pad.
22. The device of claim 17 , wherein the conductive layer comprises multiple layers, and a lowest of the multiple layers comprises a titanium/tungsten layer.