Solder bump with inner core pillar in semiconductor package

A semiconductor device, comprising:

• a substrate;
• a first conductive layer formed over the substrate;
• a single core pillar formed over the first conductive layer with the single core pillar including a width less than a width of the first conductive layer;
• a second conductive layer formed conformally over the single core pillar and first conductive layer, wherein the second conductive layer extends into a hollow interior region of the single core pillar;
• a third conductive layer formed conformally over the second conductive layer;
• and
• a bump formed over a side surface of the single core pillar.

A semiconductor device, comprising:

• a substrate;
• a first conductive layer formed over the substrate;
• a core pillar formed over the first conductive layer;
• a second conductive layer formed conformally over the core pillar and within a hollow interior region of the core pillar;
• and
• a bump formed over the core pillar and within the hollow interior region of the core pillar.

A semiconductor device, comprising:

• a substrate;
• a first conductive layer formed over the substrate;
• an under bump metallization (UBM) layer formed over the first conductive layer;
• a single core pillar formed over the UBM layer;
• a second conductive layer formed over the single core pillar and along the UBM layer, wherein the second conductive layer extends into a hollow interior region of the single core pillar;
• and
• a bump formed over the single core pillar and second conductive layer.

A semiconductor device, comprising:

• a substrate;
• a first conductive layer formed over the substrate;
• a core pillar formed over the first conductive layer with the core pillar including a width less than a width of the first conductive layer;
• a second conductive layer formed over the core pillar with the second conductive layer extending into an interior region of the core pillar;
• a third conductive layer formed over the second conductive layer;
• and
• a bump formed around the core pillar.