Nanoscale liquid phase epitaxy between Si and Au nanoparticles

A self-assembly technique was used for fabrication of a Si/metal interface in nanometer scale. Fine particles of gold of nanometer-order diameter were generated by a gas-phase condensation method and deposited on a Si substrate. Through a heat treatment and a cooling process, a nanoscopic Si-Au composite structure was formed on the surface of the Si substrate. Then, surface diffusing Si atoms played an important role for fabrication of the Si-Au structure which were epitaxially grown projecting onto the substrate. Furthermore, the Si/Au interface was atomically flat with no mixed-layer formation, and the Au nanoparticles also had the same crystal orientation as that of the Si dots in spite of a large lattice constant mismatch between them. This structure was considered to be fabricated as a result of minimization of the total surface and interface energy of the Si/Au system.