Substrate surface structure effects on microstructure of epitaxial films

Conference · Tue Dec 01 00:00:00 EST 1992

OSTI ID:6839425

Guo, J; Chang, H L.M.; Zhang, H; Lam, D J

Microstructure of epitaxial thin films grown on sapphire substrates using the metal organic chemical vapor deposition technique were found to depend on the substrates surface structure. Epitaxial TiO[sub 2] films grown on the sapphire (0001) substrates were highly-oriented polycrystal and the films on the (1120) substrates were single crystal. First-principles total energy calculations were carried out to gain atomistic understandings of sapphire surface structures and their effects on microstructure of epitaxial films. The surface terminating atom planes were found to be Al atoms for the (0001) surface and O atoms for the (1120). Minimum step heights were one sixth of the lattice constant c for the (0001) and one half of the lattice constant a for the (1120). Steps of minimum height or its odd multiples on sapphire (0001) surface double the number of variants in the deposited films. The symmetry and step of the substrate surface and symmetry of the epitaxial growth plane controlled the microstructure of the epitaxial films.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 6839425
• Report Number(s): ANL/MSD/CP-76433; CONF-921101-56; ON: DE93005562
• Resource Relation: Conference: 16. Material Research Society international symposium on the scientific basis for nuclear waste management fall meeting, Boston, MA (United States), 30 Nov - 5 Dec 1992
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
TITANIUM OXIDES
EPITAXY
MICROSTRUCTURE
ENERGY
LATTICE PARAMETERS
SAPPHIRE
SUBSTRATES
SURFACES
THIN FILMS
CHALCOGENIDES
CORUNDUM
CRYSTAL STRUCTURE
FILMS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies