Production of double-sided large-area high-T/sub c/ wafers by molecular beam epitaxy

We describe the growth and properties of high-T/sub c/ films by molecular beam epitaxy (MBE). MBE growth of high-T/sub 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 double-sided deposition on large-area substrates (so far up to 35 mm square). Films on MgO substrates typically show T/sub c/(end)> 90 K, /spl rho/(300 K)<300 /spl mu//spl Omega/cm, J/sub c//spl sim/2-5/spl times/10/sup 6/ A/cm/sup 2/ at 77 K, R/sub s/ @ 22 GHz/spl sim/2-4 m/spl Omega/ at 77 K, which are comparable to the best values for 123 films obtained at present by other growth methods.