Abstract: An embodiment of the disclosure includes a conductive bump on a semiconductor die. A substrate is provided. A bond pad is over the substrate. An under bump metallurgy (UBM) layer is over the bond pad. A copper pillar is over the UBM layer. The copper pillar has a top surface with a first width and sidewalls with a concave shape. A nickel layer having a top surface and a bottom surface is over the top surface of the copper pillar. The bottom surface of the nickel layer has a second width. A ratio of the second width to the first width is between about 0.93 to about 1.07. A solder material is over the top surface of the cap layer.

Abstract: The disclosure relates to fabrication of to a metal pillar. An exemplary method of fabricating a semiconductor device comprises the steps of providing a substrate having a contact pad; forming a passivation layer extending over the substrate having an opening over the contact pad; forming a metal pillar over the contact pad and a portion of the passivation layer; forming a solder layer over the metal pillar; and causing sidewalls of the metal pillar to react with an organic compound to form a self-assembled monolayer or self-assembled multi-layers of the organic compound on the sidewalls of the metal pillar.

Abstract: A method of forming a device includes providing a substrate, and forming a solder bump over the substrate. A minor element is introduced to a region adjacent a top surface of the solder bump. A re-flow process is then performed to the solder bump to drive the minor element into the solder bump.

Abstract: The disclosure relates to fabrication of to a metal pillar. An exemplary method of fabricating a semiconductor device comprises the steps of providing a substrate having a contact pad; forming a passivation layer extending over the substrate having an opening over the contact pad; forming a metal pillar over the contact pad and a portion of the passivation layer; forming a solder layer over the metal pillar; and causing sidewalls of the metal pillar to react with an organic compound to form a self-assembled monolayer or self-assembled multi-layers of the organic compound on the sidewalls of the metal pillar.

Abstract: An integrated circuit device includes a Cu pillar and a solder layer overlying the Cu pillar. A Co-containing metallization layer is formed to cover the Cu pillar and the solder layer, and then a thermally reflow process is performed to form a solder bump and drive the Co element into the solder bump. Next, an oxidation process is performed to form a cobalt oxide layer on the sidewall surface of the Cu pillar.

Abstract: A method of forming a device includes providing a substrate, and forming a solder bump over the substrate. A minor element is introduced to a region adjacent a top surface of the solder bump. A re-flow process is then performed to the solder bump to drive the minor element into the solder bump.

Abstract: An embodiment of the disclosure includes a conductive bump on a semiconductor die. A substrate is provided. A bond pad is over the substrate. An under bump metallurgy (UBM) layer is over the bond pad. A copper pillar is over the UBM layer. The copper pillar has a top surface with a first width and sidewalls with a concave shape. A nickel layer having a top surface and a bottom surface is over the top surface of the copper pillar. The bottom surface of the nickel layer has a second width. A ratio of the second width to the first width is between about 0.93 to about 1.07. A solder material is over the top surface of the cap layer.