Fabrication of High Quality CeO2 Thin Films on YBa2Cu3Ox Films and YBa2Cu3Ox Single Crystals for Electronic Applications

CeO2 is very promising as an insulating layer material for multilayer structures of high-Tc superconductors. CeO2 thin films were deposited by MOCVD on polished YBCO single crystals and YBCO films grown on MgO by liquid phase epitaxy. The CeO2 film quality was improved drastically using a 2-step deposition process which consists of an initial buffer layer deposition at 600–700°C followed by further deposition at 850°C. In the 2-step process, the surface consists of a dense and flat film matrix with a few separated grains as observed by AFM and SEM. Electrical measurements on patterned, 200 nm thick CeO2 films showed a relative dielectric constant of 25–30.