Effects of Zr alloying on cohesion properties of Cu/W interfaces

• Substitution of Cu or W by Zr in Cu/W interface is energetically favorable.
• Zr in CuCrZr alloy have the tendency to segregate to Cu/W interface area.
• Substitution of W by Zr increase the interface strength of Cu/W interface.
• Effects of Zr alloying are discussed in terms of electronic structures.
• Calculated results are in good agreement with experimental observations.

First principles calculation reveals that the substitution of Cu or W atoms by Zr in the Cu/W interface is energetically favorable with big negative solution energy, suggesting that the Zr atoms in the CuCrZr alloy have the tendency to segregate to the Cu/W interface area. Calculations also show that the Zr substitution for Cu atom has only a negligible effect on cohesion properties of Cu/W interface, while the substitution of W atom by Zr could significantly increase the interface strength and interface stability of the Cu/W interface, which seems good to the performance and lifetime of the Cu/W interface. In addition, the effects of Zr alloying on interface properties are discussed in terms of electronic structures to provide a deeper understanding, and the calculated results are in excellent agreement with experimental observations in the literature.