Preparation and properties of in-situ YBaCuO films on Si substrates with buffer layers

High-T/sub c/ YBaCuO superconducting films have been prepared in-situ on Si substrates with buffer layers using off-axis single-target RF magnetron sputtering. A special cylinder heater with a reflecting cone was used to grow in-situ YBaCuO films on different buffer layers, such as Y-stabilized ZrO/sub 2/ (YSZ), LaAlO/sub 3/, LaGaO/sub 3/, NdAlO/sub 3/, NdGaO/sub 3/, SrTiO/sub 3/, and MgO. The YBaCuO films on YSZ and LaAlO/sub 3/ buffer layers have T/sub c/(zero) of 84 K and 83 K, respectively. Films deposited at substrate temperatures above 650 degrees C have preferential orientation with c-axis perpendicular to the film surface. The films also show excellent surface smoothness up to atomic scale with a roughness of 5 AA. The qualities of the films as well as the dielectric properties of the substrate and buffer layers are favorable for microelectronic applications, especially for high-frequency applications. High-T/sub c/ microbridges have been fabricated using the films.