Temperature-dependent growth of LaAlO{sub 3} films on YBa{sub 2}Cu{sub 3}O{sub 7} C-axis films for multilayer structures

Conference · Sun Jan 01 00:00:00 EST 1995

OSTI ID:10115682

Hawley, M E; Houlton, R J; Raistrick, I A; Garzon, F H

Fabrication of ultra smooth films, free of micro-shorts, is essential to the development of High Temperature Superconducting (HTS) thin film devices. One such example is a SNS junction consisting of two HTS layers separated by a uniformly smooth continuous barrier material. Other schemes under consideration require multilayer structures of up to 5 - 7 epitaxially grown layers of complex oxide material. Successful fabrication of such devices necessitates understanding the epitaxial growth of polycrystalline oxide films on polycrystalline film templates. Toward this end we have developed a set of deposition parameters that produce high quality epitaxial insulating layers suitable for HTS device applications. All films in this study were grown by off-axis RF magnetron sputter deposition. LaAlO{sub 3} films were deposited over MgO grown YBa{sub 2}Cu{sub 3}O{sub 7} (YBCO) c-axis thin films at temperatures ranging from 200 to 700C and on virgin substrates at 600C. Atomic Force Microscopy, eddy current measurements, and x-ray diffraction techniques were used to monitor the effect of growth conditions on the resulting film crystallinity, nanostructure, and electrical properties. Ex-situ interrupted growth characterization of these materials has yielded new insight into the processes that control the growth mechanism and resulting microstructure. All films were polycrystalline. Below 600C, LaAlO{sub 3} films were not epitaxial while films grown at 650C showed some <200> orientation. The shape of the underlying YBCO film is most clearly evident for the film grown at 400C. Surface roughness depended on the appearance of crystals on the film surface. The superconducting properties of the underlying YBCO film required O{sub 2} annealing prior to deposition of the LaAlO{sub 3} layer.

• Research Organization: Los Alamos National Lab., NM (United States)
• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 10115682
• Report Number(s): LA-UR-94-4295; CONF-941144-34; ON: DE95005257; TRN: 95:001495
• Resource Relation: Conference: Fall meeting of the Materials Research Society (MRS),Boston, MA (United States),28 Nov - 9 Dec 1994; Other Information: PBD: [1995]
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
HIGH-TC SUPERCONDUCTORS
MICROSTRUCTURE
SURFACE PROPERTIES
EDDY CURRENT TESTING
YTTRIUM OXIDES
BARIUM OXIDES
COPPER OXIDES
LANTHANUM OXIDES
EPITAXY
DEPOSITION
ALUMINIUM OXIDES
SUPERCONDUCTING JUNCTIONS
FABRICATION
ELECTRICAL PROPERTIES
THIN FILMS
X-RAY DIFFRACTION
SUBSTRATES
SPUTTERING
TEMPERATURE DEPENDENCE
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360201