UNIFORM DEPOSITION OF YBA2CU3O7 THIN-FILMS OVER AN 8 INCH DIAMETER AREA BY A 90-DEGREES OFF-AXIS SPUTTERING TECHNIQUE

The uniform deposition of YBa2Cu3O7 (YBCO) thin films over an 8-in.-di am. area, using a 3-in.-diam. sputtering target and optimized substrat e rotation in a single target 90 degrees off-axis sputtering technique , is reported. Two dimensional maps of the thickness profile of YBCO f ilms deposited on a stationary substrate have been obtained using surf ace profilometry. These thicknesses were used in a computer simulation to predict which distance of the target from the center of the substr ate rotation will produce the maximum area with uniform thickness. The films deposited on mounted on a rotating arm displayed uniform thickn ess (<+/-5% variation) and composition (<2.3% deviation from the targe t stoichiometry) and a consistently high transition temperature (T-c>8 7.5 degrees K) and critical current density (J(c4.2 K)>2x10(7) A/cm(2) ) over an 8-in.-diam area. (C) 1996 American Institute of Physics.