Study On Rapid Fabrication Of YBCO Superconducting Thin Films Using DC Sputtering

The YBCO films are widely studied for the application on constructing fundamental microeave devices. While in the deposition of large area films, characters including the uniformity of in-plane thickness uniformity and the electric property shoule be taken into consideration. In the present paper, the multi-position box type target DC sputtering system is designed to enhance the deposition rate and the thickness uniformity of the film. Sepecified studies can be divided into five parts:1. The design of multi-position box type target DC sputtering system: The low deposition rate is deduced for the target-substrate distance can not be effectively reduced by the analisis of dual-axis rotation of the single-axis drive and rewinding target. The thickness uniformity is ensured by changing the drive mode to the rotary drive, placing the substrate on the sepecific openning of the turntable, while both sides of the substrate are equipped with opennings to get relative sputtering the two target power and the target-substrate distance can be adjusted separately. The deposition rate is efficiently enhanced by decrease the target-substrate distance to small enough. The quality of the film is ensured by adopting the unique structure of box-type target that the damage of substrate induced by re-sputter of anion efficently reduced even in tiny target-substrate distance.2. Mathematical software Matlab is employed to get the simulation and calculation of the film thickness. The scheme resolving the thickness uniformity and high deposition rate of the film are proposed by comparing the distribution of film thickness under static and dynamic status and simulating the effects deduced by the target-substrate distance, the pressure and the ratio of rotation speed and revolution speed.The simulating model is corrected by comparing the experimental data and the simulating data to guide the design of experiments.3. The systemmetric illustrastion considering the affect on the film structure induced by the revolution of substrate, the temperature, the pressure, the thickness of the film and the annealing method is given to get films equipped with good electrical characters.In conclusion, the film deposition rate is increased with more than 4 times equipped with the new film preparation systems. Simultaneously, film with the in-lane undulation no more than 3% on two-inch thin-film substrates are obtained.The sepecific scheme contraposing the thickness uniformity of large-area film are proposed. According to the unique design and structure of multi-site case type target DC sputtering system, practical ways are put forward to improve the film quality. The YBCO film are obtained on LAO single crystal substrate with critical current density Jc≥2.5MA/cm2(77K 0T 500nm).