Patent ID: 9508666
Filing Date: 2016-11-29
CPC Classification: H01L

Claim Text:
1. A method of forming a device comprising: forming a plurality of dielectric layers over a substrate; forming an under-bump-metallurgy (UBM) structure in a topmost dielectric layer of the plurality of dielectric layers; forming a first metal pillar over the substrate, the first metal pillar having a top surface disposed above a topmost dielectric layer disposed on the substrate, wherein the substrate has a through via disposed therein, wherein the first metal pillar is in electrical contact with the through via, and wherein the first metal pillar is formed over the UBM structure, and wherein the first metal pillar is in electrical contact with the through via through the UBM structure; depositing a protection material on exposed sidewalls of the first metal pillar to form a protection layer on the sidewalls of the first metal pillar, the protection material comprising a first conductive material; forming a first diffusion barrier layer over the top surface of the first metal pillar and over the protection layer, the first diffusion barrier layer being formed of a second material that is different than the first conductive material, the protection layer and the first diffusion barrier layer forming an interface therebetween; and forming a solder cap over the first diffusion barrier layer.