Semiconductor device

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.