Influence of the solubility range of intermetallic compounds on their growth behavior in hetero-junctions

The solubility range has a large effect on the growth rate of intermetallic compounds (IMCs) formed at hetero-junctions, however, is extremely difficult to determine accurately experimentally. In this work, it is studied for IMCs with a narrow solubility range how the thermodynamic properties affect their solubility and growth rate in hetero-junctions. Furthermore, a method is developed to estimate the solubility range of IMCs based on phase-field simulations combined with experimentally measured diffusion coefficients and steady-state growth rate coefficients. Application of the method to the phases ε-Cu3Sn and η-Cu6Sn5 of the Cu-Sn system at 453 K, gives the solubility ranges of the order of Δxε = 2.0 × 10−2 and Δxη = 2.6 × 10−2 using the experimental growth rates kε = 4.40 × 10−9 and kη = 7.76 × 10−9 m s−0.5 (Onishi and Fujibuchi, 1975) together with the diffusion coefficients D∼ε = 3.62 × 10−16 and D∼η = 1.01 × 10−15 m2 s−1 (Mei et al., 1992), respectively.