Rapid Preparation Of YBCO Superconducting Thin Films Based On Sputtering

Owing to its excellent properties, YBa2Cu3O7-δ(YBCO) thin film has a broadapplication prospect in the field of electricity grid, mobile communications, militarydefense, etc. In order to promote the commercial production of the YBCO film, thisresearch try to study on the rapid preparation of YBCO superconducting thin filmsbased on sputtering, including the following aspects:1. Rapid sputtering coating equipment design: Deposition rates increased by narrowingthe gap between target and substrate and using planar targets. Using the six-stationclamp can prepare six samples simultaneously, which improves the productionefficiency. To improve the deposition rate while maintained the uniformity of large-areathin films, we make target having a box-type structure and the substrate movementcombining revolution and rotation.2. By simulating the film thickness distribution, we know that the deposition ratedecreases progressively from the center of the box-type target to its edge. And with thetarget-substrate-distance increasing, the uniformity of film thickness is improved, butthe deposition rate is reduced. Uniformity of the film thickness which prepared at highsputtering pressure is superior to that of the film prepared at low sputtering pressure.3. Experimental research results of the stationary substrate’s film thickness distributionshowed that simulation results and the actual film thickness distribution was consistent,only if the deposition rate is not very high. But when the deposition rate is rapid enough,the experimental data showed that the film distribution had a depression in the centerportion, which wasn’t consistent with the theoretical simulation results.4.2-inch double-sided YBCO thin film had been prepared by self-designed rapidsputtering coating equipment. The analysis of the sample homogeneity showed that thein-plane uniformity of the film was good. But the quality of both sides of double-sidedthin films had some differences, which is mainly due to the difficulty to ensure identicalsputtering state of the two targets. The average preparation time is shortened by threetimes.5The dislocation density in the YBCO thin film was measured and calculated. The relationship between the dislocation density and critical current density (Jc) wassystematically investigated, indicating that the Jcwas much more sensitive to the screwdislocation than the edge dislocation, which was attributed to the spiral growthmechanism of YBCO thin films.