Production of double-sided large-area high-Tc wafers by molecular beam epitaxy

We describe the growth and properties of high-T-c films by molecular beam epitaxy (MBE). MBE growth of high-T-c films requires a reliable rate control for individual elements and a strong activated oxygen source. By satisfying these two requirements, we have succeeded in growing high-quality Dy-123 films. In addition, we have achieved doubleside deposition on large-area substrates (so far up to 35 mm square). Films on MgO substrates typically show T-c(end) > 90 K, rho (300 K) < 300 mu Omega cm, J(c) similar to 2-5 x 10(6) A/cm(2) at 77K, R-s @ 22GHz similar to 2-4 m Omega at 77K, which are comparable to the best values for 123 films obtained at present by other growth methods.