skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Topotaxial growth of Ti{sub 2}AlN by solid state reaction in AlN/Ti(0001) multilayer thin films

Abstract

The formation of Ti{sub 2}AlN by solid state reaction between layers of wurtzite-AlN and {alpha}-Ti was characterized by in situ x-ray scattering. The sequential deposition of these layers by dual magnetron sputtering onto Al{sub 2}O{sub 3}(0001) at 200 deg. C yielded smooth, heteroepitaxial (0001) oriented films, with abrupt AlN/Ti interfaces as shown by x-ray reflectivity and Rutherford backscattering spectroscopy. Annealing at 400 deg. C led to AlN decomposition and diffusion of released Al and N into the Ti layers, with formation of Ti{sub 3}AlN. Further annealing at 500 deg. C resulted in a phase transformation into Ti{sub 2}AlN(0001) after only 5 min.

Authors:
; ; ; ; ;  [1];  [2];  [2];  [3]
  1. Thin Film Physics Division, Department of Physics, Chemistry and Biology (IFM), Linkoeping University, S-581 83 Linkoeping (Sweden)
  2. (Germany)
  3. (IFM), Linkoeping University, S-581 83 Linkoeping (Sweden)
Publication Date:
OSTI Identifier:
20971887
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 90; Journal Issue: 17; Other Information: DOI: 10.1063/1.2731520; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM NITRIDES; ALUMINIUM OXIDES; ANNEALING; CRYSTAL GROWTH; DECOMPOSITION; DEPOSITION; EPITAXY; INTERFACES; PHASE TRANSFORMATIONS; REFLECTIVITY; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SPUTTERING; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0400-1000 K; THIN FILMS; TITANIUM COMPOUNDS; TITANIUM-ALPHA; X-RAY DIFFRACTION

Citation Formats

Hoeglund, C., Beckers, M., Schell, N., Borany, J. v., Birch, J., Hultman, L., GKSS Research Center Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht, Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden, and Thin Film Physics Division, Department of Physics, Chemistry and Biology. Topotaxial growth of Ti{sub 2}AlN by solid state reaction in AlN/Ti(0001) multilayer thin films. United States: N. p., 2007. Web. doi:10.1063/1.2731520.
Hoeglund, C., Beckers, M., Schell, N., Borany, J. v., Birch, J., Hultman, L., GKSS Research Center Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht, Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden, & Thin Film Physics Division, Department of Physics, Chemistry and Biology. Topotaxial growth of Ti{sub 2}AlN by solid state reaction in AlN/Ti(0001) multilayer thin films. United States. doi:10.1063/1.2731520.
Hoeglund, C., Beckers, M., Schell, N., Borany, J. v., Birch, J., Hultman, L., GKSS Research Center Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht, Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden, and Thin Film Physics Division, Department of Physics, Chemistry and Biology. Mon . "Topotaxial growth of Ti{sub 2}AlN by solid state reaction in AlN/Ti(0001) multilayer thin films". United States. doi:10.1063/1.2731520.
@article{osti_20971887,
title = {Topotaxial growth of Ti{sub 2}AlN by solid state reaction in AlN/Ti(0001) multilayer thin films},
author = {Hoeglund, C. and Beckers, M. and Schell, N. and Borany, J. v. and Birch, J. and Hultman, L. and GKSS Research Center Geesthacht, Max-Planck-Str. 1, D-21502 Geesthacht and Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden-Rossendorf, P.O. Box 510119, D-01314 Dresden and Thin Film Physics Division, Department of Physics, Chemistry and Biology},
abstractNote = {The formation of Ti{sub 2}AlN by solid state reaction between layers of wurtzite-AlN and {alpha}-Ti was characterized by in situ x-ray scattering. The sequential deposition of these layers by dual magnetron sputtering onto Al{sub 2}O{sub 3}(0001) at 200 deg. C yielded smooth, heteroepitaxial (0001) oriented films, with abrupt AlN/Ti interfaces as shown by x-ray reflectivity and Rutherford backscattering spectroscopy. Annealing at 400 deg. C led to AlN decomposition and diffusion of released Al and N into the Ti layers, with formation of Ti{sub 3}AlN. Further annealing at 500 deg. C resulted in a phase transformation into Ti{sub 2}AlN(0001) after only 5 min.},
doi = {10.1063/1.2731520},
journal = {Applied Physics Letters},
number = 17,
volume = 90,
place = {United States},
year = {Mon Apr 23 00:00:00 EDT 2007},
month = {Mon Apr 23 00:00:00 EDT 2007}
}
  • The nucleation and growth of Ti{sub 2}AlN thin films on MgO(111) substrates during dual direct current reactive magnetron cosputtering from Ti and Al targets in an Ar/N{sub 2} atmosphere at a substrate temperature of 690 deg. C have been investigated. Time and thickness dependent in situ specular x-ray reflectivity and x-ray diffraction in combination with cross-sectional transmission electron microscopy and Rutherford backscattering spectroscopy reveal the formation of competing phases for slight N superstoichiometry with respect to Ti{sub 2}AlN. The stoichiometry deviations initiate the layer-by-layer growth of a {approx}380 A ring thick epitaxial N-substoichiometric cubic (Ti{sub 1-x}Al{sub x})N{sub y} layer. N-vacancymore » driven diffusion of Ti and Al leads to decomposition of this metastable solid solution into nanosized cubic TiN{sub y{sup '}} and AlN{sub y{sup ''}} domains as well as to a solid-state reaction with the MgO(111) by formation of a Mg{sub 2}(Al:Ti)O{sub 4} spinel, reducing the transformed (Ti{sub 1-x}Al{sub x})N{sub y} layer thickness down to {approx}60 A ring . Local AlN{sub y{sup ''}} domains serve as templates for Ti{sub 2}AlN nucleation at higher thicknesses. At the same time TiN{sub y{sup '}} and AlN{sub y{sup ''}} serve as a sink for excess gas phase N during the subsequent polycrystalline Ti{sub 2}AlN growth with random (Ti{sub 1-x}Al{sub x})N{sub y} renucleation as a tissue phase along Ti{sub 2}AlN grain boundaries. The individual Ti{sub 2}AlN grains with vertical sizes up to the total thickness retain local epitaxy to the substrate, with basal planes nonparallel to the substrate interface. Concurrently the (Ti{sub 1-x}Al{sub x})N{sub y} layer is further reduced by inward Ti{sub 2}AlN grain growth along the basal planes.« less
  • Highlights: • Epitaxial thin films of the MAX phase Ti{sub 2}AlN are obtained by thermal annealing. • A new metastable (Ti,Al,N) solid solution with the structure of α-T is evidenced. • The formation of the MAX phase occurs at low temperature (600 °C). - Abstract: Single-phase Ti{sub 2}AlN thin films were obtained by annealing in vacuum of (Ti + Al)/AlN multilayers deposited at room temperature by magnetron sputtering onto single-crystalline (0001) 4H-SiC and (0001) Al{sub 2}O{sub 3} substrates. In-situ X-ray diffraction experiments combined with ex-situ cross-sectional transmission electron microscopy observations reveal that interdiffusion processes occur in the multilayer at amore » temperature of ∼400 °C leading to the formation of a (Ti, Al, N) solid solution, having the hexagonal structure of α-Ti, whereas the formation of Ti{sub 2}AlN occurs at 550–600 °C. Highly oriented (0002) Ti{sub 2}AlN thin films can be obtained after an annealing at 750 °C.« less
  • Conventional and high-resolution transmission electron microscopy are used to characterize the initial stages of AlN thin-film growth. AlN films are deposited by molecular beam epitaxy onto annealed (0001) oriented {alpha}-Al{sub 2}O{sub 3} (sapphire) substrates. During the initial stages of film growth (film thickness {approximately}25 nm) AlN forms islands of varying alignment with the Al{sub 2}O{sub 3} substrate. Some of the AlN islands are well aligned with the [11{bar 2}0]AlN{parallel}[10{bar 1}0] Al{sub 2}O{sub 3} and (0001)AlN{parallel}(0001)Al{sub 2}O{sub 3}, which matches closed-packed planes and directions. Other islands exhibit either an alignment of one set of planes, i.e., grains are aligned with themore » (1{bar 1}01)AlN{parallel}(11{bar 2}0) Al{sub 2}O{sub 3}, or are misaligned with respect to the Al{sub 2}O{sub 3} substrate. As the AlN film grows in thickness (film thickness {approximately}100 nm), the film becomes continuous, and the closed-packed planes and directions of the film and substrate are aligned for the majority of the film. Islands of AlN with an alignment other than this predominant orientation disturb the growth near the AlN/Al{sub 2}O{sub 3} interface and create displacements along the [0001] AlN direction in overlying AlN grains. These misaligned AlN grains provide one source for the formation of planar defects in the epitaxial AlN films. The evolution of the AlN film microstructure and the reasons for the observed orientation relationships are discussed. {copyright} {ital 1999 American Institute of Physics.}« less
  • An alcoholysis exchange between tris(hydroxymethyl)ethane (THME-H{sub 3}) or tris(hydroxymethyl)propane (THMP-H{sub 3}) and group IV metal isopropoxides yields compounds of the general formula (THMR){sub 2}M{sub 4}(OCHMe{sub 2}){sub 10}[M = Ti (R = E, 1; P, 2); Zr (R = E, 3; P, 4)]. 1 and 2 are formed in toluene, at ambient glovebox temperatures, and adopt a typical fused-M{sub 3}O{sub 12} structure where each titanium atom is surrounded by six oxygens in a slightly distorted face-shared bioctahedral arrangement. All of the oxygens of the central core are from the THMR ligand, present as {mu}-O and {mu}{sub 3}-O oxygen bridges. Generation ofmore » 3 or 4 requires heating in toluene at reflux temperatures. The zirconium atoms of 3 possess an extremely distorted edge-shared bioctahedral geometry where the central core consists of a Zr{sub 4}O{sub 8} ring (eight oxygens: six from THME ligands and two from isopropoxide ligands). Each of the zirconium atoms is six-coordinated with four bridging oxygens and two terminal isopropoxide ligands. Spincast deposited films generated from toluene solutions of 1 and 3 indicate that increased uniformity of the films and decreased hydrolysis occur in comparison to the cases of Ti(OCHMe{sub 2}){sub 4}, 5, and [Zr(OCHMe{sub 2}){sub 4}{center_dot}HOCHMe{sub 2}]{sub 2}, 6, respectively.« less
  • Growth rate-induced epitaxial orientations and crystalline quality of CeO 2 thin films grown on Al 2O 3(0001) by oxygen plasma-assisted molecular beam epitaxy were studied using in-situ and ex-situ characterization techniques. CeO 2 grows as three-dimensional (3-D) islands and two-dimensional (2-D) layers at growth rates of 1-7 Å/min, and ≥9 Å/min, respectively. The formation of epitaxial CeO 2(100) and CeO2(111) thin films occurs at growth rates of 1 Å/min and ≥ 9 Å/min, respectively. Glancing incidence x-ray diffraction (GIXRD) measurements have shown that the films grown at intermediate growth rates (2-7 Å/min) consist of polycrystalline CeO 2 along with CeOmore » 2(100). The thin film grown at 1 Å/min exhibits six in-plane domains, characteristic of well-aligned CeO 2(100) crystallites. The content of the poorly-aligned CeO 2(100) crystallites increases with increasing growth rate from 2 Å/min to 7 Å/min, and three out of six in-plane domains gradually decrease and eventually disappear, as confirmed by XRD pole figures. At growth rates ≥9 Å/min, CeO 2(111) film with single in-plane domain was identified. The formation of CeO 2(100) 3-D islands at growth rates of 1-7 Å/min is a kinetically driven process unlike at growth rates ≥9 Å/min which result in an energetically and thermodynamically more stable CeO 2(111) surface.« less