VARIATION OF METAL LAYER STACK UNDER UNDER BUMP METALLIZATION (UBM)

摘要

In certain aspects, a chip includes a pad, and a first passivation layer, wherein a first portion of the first passivation layer extends over a first portion of the pad. The chip also includes a first metal layer between the first portion of the pad and the first portion of the first passivation layer. The chip further includes an under bump metallization (UBM) electrically coupled to a second portion of the pad.