Metalorganic chemical vapour deposition of large-area high-quality YBa₂Cu₃O7-xfilms in a high-speed rotating disc reactor

Metalorganic chemical vapour deposition (MOCVD) process, which incorporates a high-speed rotating disc, has been employed for large-area deposition of high-quality YBa2Cu3O7-x (YBCO) over 50 and 75 mm diameter (100) LaAlO3 substrates. Standard deviation film thickness is less than 3% with respect to the average thickness, 3400 AA. The inductively measured transition temperatures are 89.5 K across the 50 and 75 mm diameter substrates with transition widths smaller than 1 K. The critical current densities at 77 K and zero magnetic field attain values higher than 2*106 A cm-2. Rs (77 K, 95 GHz) mapping measurements exhibit a single Rs value of 50 m Omega on 50 mm diameter LaAlO3 substrates. Only the areas within 3 mm of the wafer edge exhibit contour lines of higher Rs values. This 'up-scalable' technology can be widely employed for thin-film deposition of many perovskite oxides which have great potential for devices applications.