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Title: Dense fully 111-textured TiN diffusion barriers: Enhanced lifetime through microstructure control during layer growth

Abstract

Low-temperature deposition of TiN by reactive evaporation or sputter deposition onto amorphous substrates leads to highly underdense layers which develop mixed 111/002 orientations through competitive growth. In contrast, we demonstrate here the growth of low-temperature (450&hthinsp;{degree}C) fully dense polycrystalline TiN layers with complete 111 texture. This was achieved by reactive magnetron sputter deposition using a combination of: (1) highly oriented 25-nm-thick 0002 Ti underlayers to provide 111 TiN orientation through texture inheritance (local epitaxy) and (2) high flux (J{sub N{sub 2}{sup +}}/J{sub Ti}=14), low-energy (E{sub N{sub 2}{sup +}}{approx_equal}20&hthinsp;eV), N{sub 2}{sup +} ion irradiation in a magnetically unbalanced mode to provide enhanced adatom diffusion leading to densification during TiN deposition. The Ti underlayers were also grown in a magnetically unbalanced mode, in this case with an incident Ar{sup +}/Ti flux ratio of 2 and E{sub Ar{sup +}}{approx_equal}11&hthinsp;eV. All TiN films were slightly overstoichiometric with a N/Ti ratio of 1.02{plus_minus}0.03. In order to assess the diffusion-barrier properties of dense 111-textured TiN, Al overlayers were deposited without breaking vacuum at 100&hthinsp;{degree}C. Al/TiN bilayers were then annealed at a constant ramp rate of 3thinsp{degree}Cthinsps{sup {minus}1} to 650thinsp{degree}Cthinsps{sup {minus}1} and the interfacial reaction between Al and TiN was monitored by {ital in situ} synchrotron x-raymore » diffraction measurements. As a reference point, we find that interfacial Al{sub 3}Ti formation is observed at 450&hthinsp;{degree}C in Al/TiN bilayers in which the TiN layer is deposited directly on SiO{sub 2} in a conventional magnetically balanced mode and, hence, is underdense with a mixed 111/002 orientation. However, the onset temperature for interfacial reaction was increased to 610&hthinsp;{degree}C in bilayers with fully dense TiN exhibiting complete 111 preferred orientation. {copyright} {ital 1999 American Institute of Physics.} thinsp« less

Authors:
; ;  [1]
  1. Materials Science Department, Materials Research Laboratory, and Coordinated Science Laboratory, University of Illinois, 1101 West Springfield Avenue, Urbana, Illinois 61801 (United States)
Publication Date:
OSTI Identifier:
689924
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 86; Journal Issue: 7; Other Information: PBD: Oct 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; TITANIUM COMPOUNDS; TITANIUM NITRIDES; DIFFUSION BARRIERS; TEXTURE; MICROSTRUCTURE; SPUTTERING; THIN FILMS; VACUUM EVAPORATION; CHEMICAL REACTIONS; X-RAY DIFFRACTION; SYNCHROTRON RADIATION; INTERFACES

Citation Formats

Chun, J, Petrov, I, and Greene, J E. Dense fully 111-textured TiN diffusion barriers: Enhanced lifetime through microstructure control during layer growth. United States: N. p., 1999. Web. doi:10.1063/1.371271.
Chun, J, Petrov, I, & Greene, J E. Dense fully 111-textured TiN diffusion barriers: Enhanced lifetime through microstructure control during layer growth. United States. https://doi.org/10.1063/1.371271
Chun, J, Petrov, I, and Greene, J E. Fri . "Dense fully 111-textured TiN diffusion barriers: Enhanced lifetime through microstructure control during layer growth". United States. https://doi.org/10.1063/1.371271.
@article{osti_689924,
title = {Dense fully 111-textured TiN diffusion barriers: Enhanced lifetime through microstructure control during layer growth},
author = {Chun, J and Petrov, I and Greene, J E},
abstractNote = {Low-temperature deposition of TiN by reactive evaporation or sputter deposition onto amorphous substrates leads to highly underdense layers which develop mixed 111/002 orientations through competitive growth. In contrast, we demonstrate here the growth of low-temperature (450&hthinsp;{degree}C) fully dense polycrystalline TiN layers with complete 111 texture. This was achieved by reactive magnetron sputter deposition using a combination of: (1) highly oriented 25-nm-thick 0002 Ti underlayers to provide 111 TiN orientation through texture inheritance (local epitaxy) and (2) high flux (J{sub N{sub 2}{sup +}}/J{sub Ti}=14), low-energy (E{sub N{sub 2}{sup +}}{approx_equal}20&hthinsp;eV), N{sub 2}{sup +} ion irradiation in a magnetically unbalanced mode to provide enhanced adatom diffusion leading to densification during TiN deposition. The Ti underlayers were also grown in a magnetically unbalanced mode, in this case with an incident Ar{sup +}/Ti flux ratio of 2 and E{sub Ar{sup +}}{approx_equal}11&hthinsp;eV. All TiN films were slightly overstoichiometric with a N/Ti ratio of 1.02{plus_minus}0.03. In order to assess the diffusion-barrier properties of dense 111-textured TiN, Al overlayers were deposited without breaking vacuum at 100&hthinsp;{degree}C. Al/TiN bilayers were then annealed at a constant ramp rate of 3thinsp{degree}Cthinsps{sup {minus}1} to 650thinsp{degree}Cthinsps{sup {minus}1} and the interfacial reaction between Al and TiN was monitored by {ital in situ} synchrotron x-ray diffraction measurements. As a reference point, we find that interfacial Al{sub 3}Ti formation is observed at 450&hthinsp;{degree}C in Al/TiN bilayers in which the TiN layer is deposited directly on SiO{sub 2} in a conventional magnetically balanced mode and, hence, is underdense with a mixed 111/002 orientation. However, the onset temperature for interfacial reaction was increased to 610&hthinsp;{degree}C in bilayers with fully dense TiN exhibiting complete 111 preferred orientation. {copyright} {ital 1999 American Institute of Physics.} thinsp},
doi = {10.1063/1.371271},
url = {https://www.osti.gov/biblio/689924}, journal = {Journal of Applied Physics},
number = 7,
volume = 86,
place = {United States},
year = {1999},
month = {10}
}