Growth of epitaxial diamond on silicon via iridium/SrTiO_3 buffer layers

摘要

Large-area, single-crystalline iridium films are desired for the heteroepitaxial deposition of diamond. In the present work, we studied the potential of SrTiO_3 buffer layers for the epitaxial deposition of iridium on silicon. Molecular beam epitaxy (MBE) was used to deposit a 100-nm-thick SrTiO_3 layer. On top of this, iridium films were grown by e-beam evaporation. Subsequently, diamond was nucleated by the bias-enhanced nucleation procedure. The epitaxial orientation relationship of the resulting multilayer structure is diamond(001)[110] ||Ir(001)[110]||SrTiO_3(001)[110]||Si(001)[100]. The Ir/SrTiO_3 buffer layers lower the misorientation of the epitaxial diamond films by nearly an order of magnitude as compared to deposition directly on silicon. Oxides like yttria-stabilized zirconia (YSZ) or CeO_2/YSZ prepared by pulsed laser deposition (PLD) provide a viable alternative to the MBE-grown SrTiO_3. The crystalline quality of the diamond films and their good adhesion on the silicon substrate suggest diamond/Ir/metal-oxide/Si as a promising means to a large-area, single-crystal diamond technology.