Cubic dielectrics for superconducting electronics. In situ growth of expitaxial Sr[sub 2]AlTaO[sub 6] thin films using metalorganic chemical vapor deposition

Journal Article · Fri Dec 31 23:00:00 EST 1993 · Chemistry of Materials; (United States)

DOI:https://doi.org/10.1021/cm00037a006· OSTI ID:6770077

Han, B; Neumayer, D A; Goodreau, B H; Marks, T J; Zhang, H; Dravid, V P ^[1]

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1. Northwestern Univ., Evanston, IL (United States)

In the drive to develop HTS (high-temperature superconducting)-based electronics, the quest for new, chemically inert, HTS lattice/thermal expansion-matched, low dielectric constant/dielectric loss insulators represents a major theme. Such materials are needed as buffers, dielectrics, substrates, [open quotes]seed layers[close quotes] and overlayers. As for HTS film growth, metalorganic chemical vapor deposition (MOCVD) offers the potential in the case of dielectric films of low growth temperatures, simplified apparatus, and amenability to the large-scale coating of substrates having complex shapes. Among the dielectric materials of great current interest, the cubic ternary Sr[sub 2]AlTaO[sub 6] (SAT) is particularly attractive since it exhibits and excellent lattice and thermal expansion match with YBCO, BSCCO, and TBCCO, a low dielectric constant and low tan [delta], as well as the absence of phase transitions between 25 [degrees]C and typical HTS film growth temperatures. The presence of the latter is known to seriously degrade the electrical/microwave characteristics of proximate HTS films. Unlike a number of the binary perovskite dielectrics, the crystal structure of SAT is cubic, so that films having potentially deliterious multiple growth orientations are unlikely. The authors report here the first in situ growth of phase-pure, epitaxial SAT films by MOCVD as well as observations relevant to optimization of the MOCVD film growth process. 11 refs., 3 figs.

• OSTI ID: 6770077
• Journal Information: Chemistry of Materials; (United States), Journal Name: Chemistry of Materials; (United States) Vol. 6:1; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALKALINE EARTH METAL COMPOUNDS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL VAPOR DEPOSITION
CRYSTAL GROWTH
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DEPOSITION
DIELECTRIC MATERIALS
EPITAXY
FILMS
MATERIALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
REFRACTORY METAL COMPOUNDS
STRONTIUM COMPOUNDS
STRONTIUM OXIDES
SURFACE COATING
TANTALUM COMPOUNDS
TANTALUM OXIDES
THIN FILMS
TRANSITION ELEMENT COMPOUNDS