A REVIEW OF HIGH-TEMPERATURE SUPERCONDUCTING FILMS ON SILICON

Work on high-temperature superconducting films on silicon is reviewed. High-temperature superconducting thin films of YBa2Cu 3O7-x (YBCO) have been made on single crystal SrTiO 3 with zero-resistance transition temperatures (Tc) of 90 K and critical current densities (Jc) up to 5*106 A cm-2 at 77 K. Both thick and thin films of YBCO have been made on silicon or on silicon with a buffer layer with Tc up to 85-90 K. Polycrystalline superconducting films with unoriented grains exhibit weak link behaviour and have low values of Jc (hundreds of A cm-2 at 77 K), whereas the considerably higher value of 6*104 A cm-2 77 K has been achieved for YBCO deposited on a double epitaxial buffer layer on silicon.