Dual ion beam assisted magnetron deposition of biaxially textured YSZ and YBCO/YSZ thin films

• A technique to deposit biaxially aligned YSZ film using dual ion beam assisted deposition (DIBAD) is described.
• Two ion beam sources are mounted symmetrically at 55° angles to the substrate plane normal, making 110° angle between them.
• The crystalline biaxial alignment is strongly influenced by substrate temperature, film thickness and ion beam energy.
• Also investigated is the homo-epitaxial growth of YSZ films onto DIABAD YSZ films.
• The biaxial alignment, determined from X-ray YSZ(111) φ-scans, reaches optimum values Δφ ≈ 6.3–8.3°.

Biaxially textured yttria stabilized zirconia (YSZ) thin films were deposited on polished hastelloy and silicon substrates using ion beam assisted deposition (IBAD). The IBAD apparatus includes a planar magnetron fitted with a crystalline YSZ target to provide the film-forming species, and two Kaufman-type ion beam sources which provide Ar+ ions for bombarding the film during growth. The two ion beam sources were mounted symmetrically at 55° angles to the substrate plane normal, making 110° angle between them. Textured YSZ films were deposited under three different IBAD conditions: (a) films were bombarded by a single ion beam source (SIBAD), (b) films were bombarded by a single ion beam source for a time alternating from the two symmetric directions (AIBAD), and (c) by dual ion beam assisted deposition (DIBAD) where the film was bombarded simultaneously from the two symmetric directions. The X-ray φ-scan results indicate that DIBAD followed by epitaxial growth of YSZ produced the highest degree of biaxial texture in YSZ films. Superconducting yttrium barium copper oxide (YBCO) films deposited on highly textured DIBAD YSZ films had φ-scan full width at half maximum of 7.1° and 5.5° for hastelloy and silicon substrates, respectively.