Patent ID: 8552529

Claim:
A semiconductor device, comprising: a substrate; a first metal layer overlying the substrate; a dielectric layer overlying the first metal layer; and a second metal layer overlying the dielectric layer, wherein the first metal layer comprises: a first body-centered cubic lattice metal layer; a first underlayer, underlying the first body-centered cubic lattice metal layer, wherein the first underlayer is metal of body-centered cubic lattice and comprises titanium (Ti), tungsten (W), molybdenum (Mo) or niobium (Nb); wherein the second metal layer comprises: a second body-centered cubic lattice metal layer; a second underlayer, underlying the second body-centered cubic lattice metal layer; and a second interface of body-centered cubic lattice between the second body-centered cubic lattice metal layer and the second underlayer, wherein the first metal layer further comprises: an aluminum-copper alloy layer underlying the first underlayer; a third body-centered cubic lattice metal layer underlying the aluminum-copper alloy layer; a third underlayer, underlying the third body-centered cubic lattice metal layer; and a third interface of body-centered cubic lattice between the third body-centered cubic lattice metal layer and the third underlayer; and a first interface of body-centered cubic lattice between the first body-centered cubic lattice metal layer and the first underlayer.