Study of Cu-growth feature by selective low-pressure chemical vapor deposition using a CuI precursor

In this study, Cu-growth features are investigated using selective low-pressure CVD of Cu on Ru(001) using a copper(I) iodide precursor. While discrete columnar grains are formed below 320 °C, lateral Cu islands are grown above 380 °C. The CuI dissociation efficiency, which depends on the growth temperature, indicates two activation energies corresponding to I2 desorption from Cu and Ru. The activation energy below 320 °C and above 380 °C are identified as the energies required for the desorption of I2 from Cu(111) and Ru(001), respectively. At 400 °C, nucleation occurs at the initial stage, followed by the lateral growth of Cu-islands. A proposed growth model, involving dissociated Cu-atom contributions toward increasing the Cu-island height and Cu coverage on Ru, can explain the island growth features dependent on the growth time. Further, the growth model reveals an important factor to achieve thinner Cu layers growth entirely covering Ru.