Semiconductor device and method for manufacturing the same

A semiconductor device, comprising:

• a first circuit layer;
• a copper pillar disposed adjacent to the first circuit layer;
• a second circuit layer comprising an electrical contact and a surface finish layer disposed on the electrical contact, wherein a material of the surface finish layer is a combination of at least two of nickel, gold, and palladium;
• and
• a solder layer disposed between the copper pillar and the surface finish layer, the solder layer comprising a first intermetallic compound (IMC) and a second IMC, wherein the first IMC comprises a combination of two or more of copper, nickel and tin, the second IMC includes a combination of gold and tin, a combination of palladium and tin, or both, the first IMC comprises a top layer and a bottom layer, and materials of the top layer and the bottom layer are the same.