Semiconductor assemblies and structures
Semiconductor assemblies, structures, and methods of fabrication are disclosed. A coating is formed on an electrically conductive pillar. The coating, which may be formed from at least one of a silane material and an organic solderability protectant material, may bond to a conductive material of the electrically conductive pillar and, optionally, to other metallic materials of the electrically conductive pillar. The coating may also bond to substrate passivation material, if present, or to otherwise-exposed surfaces of a substrate and a bond pad. The coating may be selectively formed on the conductive material. Material may not be removed from the coating after formation thereof and before reflow of the solder for die attach. The coating may isolate at least the conductive material from solder, inhibiting solder wicking or slumping along the conductive material and may enhance adhesion between the resulting bonded conductive element and an underfill material.
1. A semiconductor assembly, comprising:
a conductive element on a semiconductor substrate;
solder electrically connecting the conductive element to a landing pad of another substrate; and
a coating on the conductive element and substantially conforming to and fully covering an at least partially rounded exterior surface of the solder, the coating comprising at least one of metal-oxygen-silicon bonds, silicon-oxygen-silicon bonds, metal-sulfur bonds and silicon bonds, and an organic solderability protectant material.
2. The semiconductor assembly of claim 1 , wherein the coating also substantially conforms to the conductive element.
3. The semiconductor assembly of claim 1 , wherein the conductive element contacts a bond pad, and the coating is further on the bond pad.
4. The semiconductor assembly of claim 3 , wherein the coating fully covers sidewalls of the bond pad.
5. The semiconductor assembly of claim 1 , wherein the coating is bonded to the solder.
6. The semiconductor assembly of claim 1 , wherein the coating is formed from a silane material.
7. A structure, comprising:
a conductive material disposed over a substrate and supporting a solder mass;
a barrier material disposed between the conductive material and the solder mass: and
a coating bonded to the conductive material and to the barrier material and isolating an exterior surface of the conductive material and an exterior surface of the barrier material from the solder mass, the coating substantially conforming to and extending along a rounded exterior surface of the solder mass from the barrier material to a landing pad, the coating comprising at least one of:
an organic solderability protectant material, and
silicon bonded to oxygen.
8. The structure of claim 7 , wherein the coating is bonded to the conductive material, the barrier material, and the solder mass.
9. The structure of claim 7 , wherein the coating is bonded to the conductive material by at least one of metal-oxygen-silicon bonds and metal-sulfur bonds.
10. The structure of claim 7 , wherein the coating comprises the silicon bonded to oxygen.
11. The structure of claim 10 , wherein the coating is formed from a silane material.
12. The structure of claim 7 , further comprising a substrate passivation material at least partially overlying a bond pad on the substrate, wherein the coating is at least partially disposed on the substrate passivation material.
13. A structure, comprising:
a conductive material disposed directly on a bond pad over a semiconductor substrate without a passivation material on the bond pad;
a coating bonded to the conductive material and substantially conforming to a rounded surface of a solder mass overlying the conductive material, the coating comprising at least one of an organic solderability protectant material and silicon-to-oxygen bonds; and
a dielectric underfill material on the coating,
at least one of the coating and the dielectric underfill material in physical contact with the semiconductor substrate.
14. The structure of claim 13 , further comprising:
a barrier material disposed over an end of the conductive material,
wherein the coating is bonded to the conductive material and the barrier material.
15. The structure of claim 13 , wherein the coating is bonded to the conductive material by at least one of metal-oxygen-silicon bonds and metal-sulfur bonds.
16. The structure of claim 13 , wherein the coating is also bonded to the bond pad.