Conductive contacts having varying widths and method of manufacturing same

摘要

A bump structure includes a contact element formed on a substrate and a passivation layer overlying the substrate. The passivation layer includes a passivation opening exposing the contact element. The bump structure also includes a polyimide layer overlying the passivation layer and an under bump metallurgy (UBM) feature electrically coupled to the contact element. The polyimide layer has a polyimide opening exposing the contact element, and the under bump metallurgy feature has a UBM width. The bump structure further includes a copper pillar on the under bump metallurgy feature. A distal end of the copper pillar width, and the UBM width is greater than the pillar width.

主权项

1. A bump structure, comprising:
a contact element formed over a substrate; a passivation layer overlying the substrate, the passivation layer having a passivation opening exposing the contact element; a polyimide layer overlying the passivation layer, the polyimide layer having a polyimide opening exposing the contact element; an under bump metallurgy (UBM) feature electrically coupled to the contact element, the under bump metallurgy feature having a UBM width; and a copper pillar on the under bump metallurgy feature, a distal end of the copper pillar having a pillar width, the UBM width greater than the pillar width, wherein a portion of the copper pillar over a topmost surface of the under bump metallurgy feature has a substantially linear profile.