In this study, we use first-principles simulations to study the adsorption of copper onto H-terminated and partially OH-terminated silicon surfaces. We show that, in contrast to previous studies, copper adsorbs strongly to the H-terminated silicon surface and that the adsorption energy is significantly dependent on the local bonding environment. The addition of a hydroxide group increases the average adsorption energy while reducing the range of adsorption energies due to the strong interaction between copper and oxygen. Our results predict that copper will generally prefer to adsorb at dihydride sites on the surface, agreeing with experimental studies of copper nucleation. The adsorption energy hierarchy predicted by the calculations strongly supports the suggestion that copper acts as a micromask in wet chemical etching, blocking reactive sites.
Foster, A. S., Gosálvez, M. A., Hynninen, T., Nieminen, R. M., & Sato, K. (2007). First-principles calculations of Cu adsorption on an H-terminated Si surface. Physical Review B, 76(7), 1-8. . https://doi.org/10.1103/PhysRevB.76.075315