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Title: Thermal behavior of the microstructure and the electrical properties of magnetron-sputtered high-k titanium silicate thin films

Abstract

We report on the high-temperature stability of high-dielectric-constant (high-k) titanium silicate (Ti{sub 0.5}Si{sub 0.5}O{sub 2}) thin films deposited by means of a magnetron sputtering process. We have investigated the effect of substrate deposition temperature T{sub d} (in the 20-600 deg. C range) and postdeposition annealing temperature T{sub a} (in the 200-800 deg. C range) on the electrical, microstructural, and optical properties of the films. The Ti-silicate films grown at room temperature were found to exhibit a combination of excellent electrical properties, including a k-value of 16.5, a leakage current as low as 3 nA at 1 MV/cm, and a dissipation factor tan({delta})<0.01. On the other hand, when the processing temperature (T{sub d} or T{sub a}) is {>=}300 deg. C, the leakage current of the films is found to degrade progressively. The x-ray diffraction, Raman spectroscopy, and transmission electron microscopy characterizations have shown that the Ti-silicate films exhibit an amorphous microstructure up to a temperature of about 600 deg. C. For higher temperatures, (i.e., T{sub d} of 600 deg. C or a T{sub a}{>=}700 deg. C) some anatase TiO{sub 2} nanocrystallites (in the 1.5-5 nm size range) formation is evidenced. This TiO{sub 2} nanocrystallite precipitation results from a thermally induced phasemore » segregation of TiO{sub 2}-rich and SiO{sub 2}-rich environments, which is shown to be initiated at rather low processing temperatures. This progressive phase segregation, which leads to the precipitation of a low band gap and leaky TiO{sub 2}-rich phase in the films, is believed to be at the origin of the observed degradation of the leakage current of the Ti-silicate films with increasing temperatures (T{sub d} or T{sub a})« less

Authors:
;  [1]
  1. Institut National de la Recherche Scientifique, INRS-Energie, Materiaux et Telecommunications, 1650 Boulevard Lionel-Boulet, C.P. 1020, Varennes, Quebec J3X 1S2 (Canada)
Publication Date:
OSTI Identifier:
21137344
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 103; Journal Issue: 11; Other Information: DOI: 10.1063/1.2937241; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ANNEALING; DIELECTRIC MATERIALS; DISSIPATION FACTOR; LEAKAGE CURRENT; MICROSTRUCTURE; NANOSTRUCTURES; RAMAN SPECTROSCOPY; SEGREGATION; SEMICONDUCTOR MATERIALS; SILICON OXIDES; SPUTTERING; TEMPERATURE DEPENDENCE; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TEMPERATURE RANGE 1000-4000 K; THIN FILMS; TITANIUM OXIDES; TITANIUM SILICATES; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION

Citation Formats

Brassard, D, and El Khakani, M A. Thermal behavior of the microstructure and the electrical properties of magnetron-sputtered high-k titanium silicate thin films. United States: N. p., 2008. Web. doi:10.1063/1.2937241.
Brassard, D, & El Khakani, M A. Thermal behavior of the microstructure and the electrical properties of magnetron-sputtered high-k titanium silicate thin films. United States. https://doi.org/10.1063/1.2937241
Brassard, D, and El Khakani, M A. 2008. "Thermal behavior of the microstructure and the electrical properties of magnetron-sputtered high-k titanium silicate thin films". United States. https://doi.org/10.1063/1.2937241.
@article{osti_21137344,
title = {Thermal behavior of the microstructure and the electrical properties of magnetron-sputtered high-k titanium silicate thin films},
author = {Brassard, D and El Khakani, M A},
abstractNote = {We report on the high-temperature stability of high-dielectric-constant (high-k) titanium silicate (Ti{sub 0.5}Si{sub 0.5}O{sub 2}) thin films deposited by means of a magnetron sputtering process. We have investigated the effect of substrate deposition temperature T{sub d} (in the 20-600 deg. C range) and postdeposition annealing temperature T{sub a} (in the 200-800 deg. C range) on the electrical, microstructural, and optical properties of the films. The Ti-silicate films grown at room temperature were found to exhibit a combination of excellent electrical properties, including a k-value of 16.5, a leakage current as low as 3 nA at 1 MV/cm, and a dissipation factor tan({delta})<0.01. On the other hand, when the processing temperature (T{sub d} or T{sub a}) is {>=}300 deg. C, the leakage current of the films is found to degrade progressively. The x-ray diffraction, Raman spectroscopy, and transmission electron microscopy characterizations have shown that the Ti-silicate films exhibit an amorphous microstructure up to a temperature of about 600 deg. C. For higher temperatures, (i.e., T{sub d} of 600 deg. C or a T{sub a}{>=}700 deg. C) some anatase TiO{sub 2} nanocrystallites (in the 1.5-5 nm size range) formation is evidenced. This TiO{sub 2} nanocrystallite precipitation results from a thermally induced phase segregation of TiO{sub 2}-rich and SiO{sub 2}-rich environments, which is shown to be initiated at rather low processing temperatures. This progressive phase segregation, which leads to the precipitation of a low band gap and leaky TiO{sub 2}-rich phase in the films, is believed to be at the origin of the observed degradation of the leakage current of the Ti-silicate films with increasing temperatures (T{sub d} or T{sub a})},
doi = {10.1063/1.2937241},
url = {https://www.osti.gov/biblio/21137344}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 11,
volume = 103,
place = {United States},
year = {Sun Jun 01 00:00:00 EDT 2008},
month = {Sun Jun 01 00:00:00 EDT 2008}
}