BUMP STRUCTURE, SEMICONDUCTOR PACKAGE INCLUDING THE BUMP STRUCTURE, AND METHOD OF FORMING THE BUMP STRUCTURE

摘要

A bump structure includes an under bump metal (UBM) layer, a pillar bump and a capping layer. The UBM layer is disposed on a pad of a semiconductor chip. The pillar bump is disposed on the UBM layer. The capping layer is disposed on the UBM layer and surrounds an outer surface of the pillar bump. The capping layer has a height of about 0.5 times to 0.7 times a height of the pillar bump as measured from the UBM layer where an upper portion of the pillar bump is exposed. The capping layer suppresses stresses applied to a metal wiring in the semiconductor chip while attaching the semiconductor chip to a package substrate and maintain an adhesion force between the pillar bump and the package substrate.