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Title: Bimodal substrate biasing to control γ-Al{sub 2}O{sub 3} deposition during reactive magnetron sputtering

Abstract

Al{sub 2}O{sub 3} thin films have been deposited at substrate temperatures between 500 °C and 600 °C by reactive magnetron sputtering using an additional arbitrary substrate bias to tailor the energy distribution of the incident ions. The films were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The film structure being amorphous, nanocrystalline, or crystalline was correlated with characteristic ion energy distributions. The evolving crystalline structure is connected with different levels of displacements per atom (dpa) in the growing film as being derived from TRIM simulations. The boundary between the formation of crystalline films and amorphous or nanocrystalline films was at 0.8 dpa for a substrate temperature of 500 °C. This threshold shifts to 0.6 dpa for films grown at 550 °C.

Authors:
; ; ; ;  [1];  [2]
  1. Research Group Reactive Plasmas, Ruhr-Universität Bochum, D-44801 Bochum (Germany)
  2. Materials Chemistry, RWTH Aachen University, D-52074 Aachen (Germany)
Publication Date:
OSTI Identifier:
22217999
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 114; Journal Issue: 11; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; ATOMIC DISPLACEMENTS; DEPOSITION; ENERGY SPECTRA; FABRICATION; FOURIER TRANSFORM SPECTROMETERS; INFRARED SPECTRA; IONS; MAGNETRONS; NANOSTRUCTURES; SPUTTERING; SUBSTRATES; THIN FILMS; X-RAY DIFFRACTION

Citation Formats

Prenzel, Marina, Kortmann, Annika, Stein, Adrian, Keudell, Achim von, Nahif, Farwah, and Schneider, Jochen M. Bimodal substrate biasing to control γ-Al{sub 2}O{sub 3} deposition during reactive magnetron sputtering. United States: N. p., 2013. Web. doi:10.1063/1.4819227.
Prenzel, Marina, Kortmann, Annika, Stein, Adrian, Keudell, Achim von, Nahif, Farwah, & Schneider, Jochen M. Bimodal substrate biasing to control γ-Al{sub 2}O{sub 3} deposition during reactive magnetron sputtering. United States. doi:10.1063/1.4819227.
Prenzel, Marina, Kortmann, Annika, Stein, Adrian, Keudell, Achim von, Nahif, Farwah, and Schneider, Jochen M. 2013. "Bimodal substrate biasing to control γ-Al{sub 2}O{sub 3} deposition during reactive magnetron sputtering". United States. doi:10.1063/1.4819227.
@article{osti_22217999,
title = {Bimodal substrate biasing to control γ-Al{sub 2}O{sub 3} deposition during reactive magnetron sputtering},
author = {Prenzel, Marina and Kortmann, Annika and Stein, Adrian and Keudell, Achim von and Nahif, Farwah and Schneider, Jochen M.},
abstractNote = {Al{sub 2}O{sub 3} thin films have been deposited at substrate temperatures between 500 °C and 600 °C by reactive magnetron sputtering using an additional arbitrary substrate bias to tailor the energy distribution of the incident ions. The films were characterized by X-ray diffraction and Fourier transform infrared spectroscopy. The film structure being amorphous, nanocrystalline, or crystalline was correlated with characteristic ion energy distributions. The evolving crystalline structure is connected with different levels of displacements per atom (dpa) in the growing film as being derived from TRIM simulations. The boundary between the formation of crystalline films and amorphous or nanocrystalline films was at 0.8 dpa for a substrate temperature of 500 °C. This threshold shifts to 0.6 dpa for films grown at 550 °C.},
doi = {10.1063/1.4819227},
journal = {Journal of Applied Physics},
number = 11,
volume = 114,
place = {United States},
year = 2013,
month = 9
}
  • The fluxes of ions and neutral sputtered particles incident at the growth surface during the deposition of TiN by reactive magnetron sputtering from a Ti target in mixed Ar+N[sub 2] discharges were determined using a combination of [ital in] [ital situ] double-modulation mass spectrometry, Langmuir probe, discharge, deposition rate, and film composition measurements. The N[sub 2] fraction [ital f][sub N[sub 2]] in the discharge was varied from 0 to 1 with the total pressure maintained at 3 mTorr (0.4 Pa). Target nitridation, observed directly through the detection of sputter-ejected TiN molecules, was found to occur over the narrow [ital f][submore » N[sub 2]] range between [congruent]0.035 and 0.06. With [ital f][sub N[sub 2]][lt]0.1, more than 94% of the ion flux incident at the substrate is Ar[sup +] while for pure N[sub 2] discharges, N[sup +][sub 2] accounts for more than 95% of the incident ions. Both the incident Ar[sup +] and N[sup +][sub 2] ion fluxes are highly monoenergetic with energies corresponding to [ital eV][sub [ital s]], where [ital V][sub [ital s]] is the applied negative substrate bias with respect to the plasma potential. However, the energy distributions of incident Ti[sup +] and N[sup +] ions are extended due to the high-energy tails in their sputter-ejection energy distributions. The primary sputter-ejected particles are Ti and N atoms. TiN, TiN[sup +], and Ti[sup +] do not contribute significantly to film growth kinetics.« less
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