Epitaxial growth of copper silicides by “bilayer” technique on monocrystalline silicon with and without native SiOx

Cu/Au and Au/Cu multilayered films were thermally evaporated alternatively on (1 0 0) and (1 1 1) monocrystal silicon substrates with and without native silicon oxide. After heat treatment in situ either at 400 or at 600 °C, the interfacial transformations were analyzed by Rutherford backscattering spectrometry, θ–2θ X-ray diffraction and scanning electron microscopy. It was found, that the samples surface was covered with Cu3Si and Cu4Si crystallites of square, rectangular and hexagonal basis shapes well-oriented on Si(1 0 0) and of triangular shape on Si(1 1 1) owing to the strong intermixing between the different elements. The dilution of the entire gold deposited layer in the Cu–Au–Si formed mixture suggests that gold atoms have a high limit solubility in the formed polycrystalline Cu3Si and Cu4Si silicides.