Using single‐target off‐axis sputter deposition, high quality superconducting films of YBa2Cu3O7−&dgr;were madeinsitu. These films have properties which are distinctly different from those of bulk ceramics and of post‐deposition annealed films. Their superconducting resistive transitions remain sharp regardless of the value ofTcbetween 75 and 86 K. Normal‐state conductivities are as high or higher than the best single crystals. Critical current densities as high as 6×107A/cm2at 4.2 K.Tc(R=0) falls off with film thickness down to 10 K for 35–40 A˚ films. All of the above properties are relatively insensitive to compositional variation. The results can be explained if theinsitugrowth results in well‐formed CuO2planes with defects occurring elsewhere.