EPITAXIAL PLANARIZATION OF PATTERNED YTTRIA-STABILIZED ZIRCONIA SUBSTRATES FOR MULTILAYER STRUCTURES

In situ planarization of epitaxial films has been demonstrated. This i s a critical technology for the processing of any epitaxial multilayer device. Ion beam assisted deposition (IBAD) has been used to planariz e patterned yttria-stabilized ZrO2 (YSZ)(001) substrates using YSZ fil ms. X-ray diffraction measurements have shown that the IBAD YSZ grows homoepitaxially. The IBAD planarization mechanism has similarities to those previously observed for rf bias sputtering. Critical current den sities of up to 7x10(5) A/cm(2) at 77 R have been measured for Ba2YCu3 O7-x (BYC) films deposited on planarized patterned YSZ substrates usin g pulsed laser deposition. In contrast, BYC deposited on unplanarized patterned YSZ substrates did not become fully superconducting for meas urements down to 25 K. (C) 1995 American Institute of Physics.