Microstructural evolution and Poisson ratio of epitaxial ScN grown on TiN(001)/MgO(001) by ultrahigh vacuum reactive magnetron sputter deposition

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.371555· OSTI ID:692546

Gall, D; Petrov, I; Desjardins, P; Greene, J E ^[1]

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1. Materials Science Department, Coordinated Science Laboratory, and Materials Research Laboratory, University of Illinois, 1101 West Springfield Avenue, Urbana, Illinois 61801 (United States)

ScN layers, 60{endash}80 nm thick, were grown at 800&hthinsp;{degree}C on 220-nm-thick epitaxial TiN(001) buffer layers on MgO(001) by ultrahigh vacuum reactive magnetron sputter deposition in pure N{sub 2} discharges. The films are stoichiometric with N/Sc ratios, determined by Rutherford backscattering spectroscopy and x-ray photoelectron spectroscopy, of 1.00{plus_minus}0.02. Plan-view and cross-sectional transmission electron microscopy analyses showed that the films are single crystals which appear defect free up to a critical thickness of {approx_equal}15 nm, above which an array of nanopipes form with their tubular axis along the film growth direction and extending to the free surface. The nanopipes are rectangular in cross section with areas of {approx_equal}1.5{times}5&hthinsp;nm{sup 2} and are self-organized along {l_angle}100{r_angle}, directions with an average separation of {approx_equal}40 nm. Their formation is the result of periodic kinetic surface roughening which leads to atomic self-shadowing and, under limited adatom mobility conditions, to deep cusps which are the origin of the nanopipes. The ScN layers are nearly relaxed, as determined from x-ray diffraction {theta}-2{theta} scans in both reflection and transmission, with only a small residual compressive strain due to differential thermal contraction. The Poisson ratio of ScN was found to be 0.20{plus_minus}0.04, in good agreement with {ital ab initio} calculations. {copyright} {ital 1999 American Institute of Physics.}

• OSTI ID: 692546
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 86; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
EPITAXY
MICROSTRUCTURE
PHOTOELECTRON SPECTROSCOPY
POISSON RATIO
RESIDUAL STRESSES
RUTHERFORD SCATTERING
SCANDIUM COMPOUNDS
SCANDIUM NITRIDES
SPUTTERING
THIN FILMS
TITANIUM NITRIDES