We have prepared high‐qualityc‐axis oriented superconducting YBa2Cu3O7−&dgr;thin films on Si (100) substrates with CoSi2buffer layers byinsitupulsed laser ablation processing. The films were characterized by x‐ray diffraction, four‐point ac electrical resistivity, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) techniques. YBa2Cu3O7−&dgr;films were found to be textured withcaxis perpendicular to the substrate. A plot of normalized resistance against temperature exhibited a metallic behavior followed by an onset superconducting transition at 91 K with zero resistance temperature (Tc0) of 83 K. Cross‐sectioned TEM results showed quite smooth interface between CoSi2and Si with little interdiffusion; however, a reacted zone was observed between CoSi2and YBa2Cu3O7−&dgr;layers.