Interfacial reaction of W/Cu examined by an n-body potential through molecular dynamics simulations

Concerning the possible barrier function of W in the case of Cu metallization technology, the interfacial reaction between the equilibrium immiscible Cu and W was studied by molecular dynamics simulations, based on a proven realistic Cu-W potential derived under the embedded atom method. The simulation results revealed that the Cu (W) atoms did not diffuse into the W (Cu) lattice within a temperature range of 300-900 K. Moreover, even a disordered interlayer was preset at the Cu-W interface, mutual diffusion was not detectable and the disordered interlayer did not expand either, while it was reported to occur in the Ta/Cu bilayer at around 450-600degreesC.