Bump structure having a side recess and semiconductor structure including the same
In some embodiments, the present disclosure relates to a method of integrated chip bonding. The method is performed by forming a metal layer on a substrate, and forming a solder layer on the metal layer. The solder layer is reflowed. The metal layer and the solder layer have sidewalls defining a recess that is at least partially filled by the solder layer during reflowing of the solder layer.
1. A method of integrated chip bonding, comprising:
forming a metal layer on a substrate;
forming a solder layer on the metal layer; and
reflowing the solder layer, wherein the metal layer has sidewalls defining a recess that is at least partially filled by the solder layer when reflowing the solder layer.
2. The method of claim 1 , wherein the metal layer comprises an outermost sidewall that has a first height and the recess has a second height that is substantially equal to the first height.
3. The method of claim 1 , further comprising:
forming the metal layer on an under-bump metallurgy layer, wherein the under-bump metallurgy layer is disposed between the metal layer and the substrate.
4. The method of claim 1 , further comprising:
bringing the solder layer into contact with a conductive trace disposed on a second substrate prior to reflowing the solder layer.
5. The method of claim 4 , wherein the solder layer contacts sidewalls of the conductive trace after reflowing the solder layer.
6. The method of claim 1 , wherein a volume ratio of the recess to the solder layer is less than or equal to about 0.1.
7. The method of claim 1 , wherein the metal layer comprises:
a first end;
a second end opposite the first end;
a first side connected between the first end and the second end; and
a second side opposite the first side and connected between the first end and the second end, wherein the recess is arranged within the second side.
8. The method of claim 7 ,
wherein the metal layer is substantially symmetric along a first line bisecting the first end and the second end; and
wherein the metal layer is substantially symmetric along a second line bisecting the first side and the second side.
9. A method of integrated chip bonding, comprising:
forming a bump structure comprising a first end, a second end opposite the first end, and a first side connected between the first end and the second end, wherein the first side defines a recess and wherein the bump structure has a smaller width at a center of the first side than between the center of the first side and the first end;
forming a solder material on the bump structure; and
reflowing the solder material, wherein during reflowing of the solder material a portion of the solder material flows into the recess.
10. The method of claim 9 , wherein the bump structure is substantially symmetric along a first line bisecting the bump structure in a first direction.
11. The method of claim 10 , wherein the bump structure is asymmetric along a second line bisecting the bump structure in a second direction perpendicular to the first direction.
12. The method of claim 9 , further comprising:
bringing the solder material into contact with a conductive structure prior to reflowing the solder material, wherein the conductive structure is separated from the bump structure by the solder material.
13. The method of claim 9 , wherein the bump structure further comprises:
a second side opposite the first side and connected between the first end and the second end, wherein the second side does not have a recess.
14. The method of claim 9 , wherein forming the bump structure comprises:
forming a metal layer on an under-bump metallurgy layer, wherein the under-bump metallurgy layer is disposed between the metal layer and a substrate.
15. The method of claim 9 , further comprising:
bringing the solder material into contact with a conductive trace prior to reflowing the solder material, wherein the conductive trace is separated from the bump structure by the solder material.
16. The method of claim 15 , wherein the solder material is disposed along sidewalls of the conductive trace after reflowing the solder material.
17. The method of claim 15 , wherein the solder material laterally extends past opposing sides of the conductive trace.
18. A method of integrated chip bonding, comprising:
forming a conductive bump comprising a top surface, a bottom surface, and a recess between the top surface and the bottom surface, wherein the bottom surface has a first width and the top surface has a second width that is greater than the first width; and
forming a solder layer over the conductive bump, wherein the solder layer fills a part of the recess.
19. The method of claim 18 , wherein forming the solder layer comprises performing a reflow process on a solder to fill the part of the recess and to contact sidewalls of the conductive bump.
20. The method of claim 18 , wherein the recess is located on a first side of the conductive bump connected between the top surface and the bottom surface, wherein the conductive bump further comprises a second side opposite the first side, and wherein the second side is a non-recessed side.