Large area deposition of YBa2Cu3O7-x films by pulsed laser ablation

A special patented design is built up to produce homogeneous YBa2Cu3O7-x (YBCO) films by pulsed laser deposition (PLD) over areas as large as 7 x 20 cm(2). The use of a line focus (8 cm) reduces the substrate movement to one dimension. The demands on plasma homogenization, substrate scanning and film temperature during the deposition process for large area PLD are discussed and their technical realization is presented. First results of 1 x 1 cm(2) YBCO films at different positions on the substrate holder (11 x 28 cm(2)) show homogeneous deposition conditions. The transition temperatures of the deposited YBCO thin films on 1 x 1 cm(2) SrTiO3 substrates are T-c = 89 K with critical currents of 4 x 10(6) A/cm(2) at T = 77 K. The structural properties of these films (chi(min) = 4.5%) indicate also their high crystalline quality. The variation of film thickness perpendicular to the scanning direction is less than +/-9% and along the scanning direction +/-7%. (C) 1998 American Institute of Physics.