CaF2 films were grown on <img src="http:/img/fbpe/bjp/v30n3/cem.gif" alt="cem.gif (148 bytes)"> silicon using the neutral cluster beam deposition technique. These films were highly crystalline and c-axis oriented. Superconducting YBCO thin films were grown on the CaF2 buffered silicon using the laser ablation technique. These films showed Tc(onset) at 90K and Tc(zero) at 86K. X-ray diffraction analysis showed that the YBCO lms were also oriented along the c-axis.