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Title: Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials

Abstract

In this paper, the authors study the protective effect against oxidation of a thin layer of atomic layer deposited (ALD) aluminum oxide (Al{sub 2}O{sub 3}). Nitrogen doped silicon carbide (poly-SiC:N) based microheaters coated with ALD Al{sub 2}O{sub 3} are used as test structure to investigate the barrier effect of the alumina layers to oxygen and water vapor at very high temperature (up to 1000 °C). Different device sets have been fabricated changing the doping levels, to evaluate possible interaction between the dopants and the alumina layer. The as-deposited alumina layer morphology has been evaluated by means of AFM analysis and compared to an annealed sample (8 h at 1000 °C) to estimate the change in the grain structure and the film density. The coated microheaters are subjected to very long oxidation time in dry and wet environment (up to 8 h at 900 and 1000 °C). By evaluating the electrical resistance variation between uncoated reference devices and the ALD coated devices, the oxide growth on the SiC is estimated. The results show that the ALD alumina coating completely prevents the oxidation of the SiC up to 900 °C in wet environment, while an oxide thickness reduction of 50% is observed at 1000 °C compared tomore » uncoated devices.« less

Authors:
;  [1];  [2];  [3]
  1. Department of Microelectronic, Delft University of Technology, Feldmannweg 17, 2628 CT Delft (Netherlands)
  2. Department of Electronic, University of Naples Federico II, Piazzale Tecchio, 80125 Napoli (Italy)
  3. Department of Microelectronic, Delft University of Technology, Feldmannweg 17, 2628 CT, Delft (Netherlands)
Publication Date:
OSTI Identifier:
22392115
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 1; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; LAYERS; OXIDATION; SILICON CARBIDES; TEMPERATURE RANGE 1000-4000 K; THIN FILMS; WATER VAPOR

Citation Formats

Fiorentino, Giuseppe, E-mail: g.fiorentino@tudelft.nl, Morana, Bruno, Forte, Salvatore, and Sarro, Pasqualina Maria. Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials. United States: N. p., 2015. Web. doi:10.1116/1.4904208.
Fiorentino, Giuseppe, E-mail: g.fiorentino@tudelft.nl, Morana, Bruno, Forte, Salvatore, & Sarro, Pasqualina Maria. Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials. United States. doi:10.1116/1.4904208.
Fiorentino, Giuseppe, E-mail: g.fiorentino@tudelft.nl, Morana, Bruno, Forte, Salvatore, and Sarro, Pasqualina Maria. Thu . "Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials". United States. doi:10.1116/1.4904208.
@article{osti_22392115,
title = {Role of atomic layer deposited aluminum oxide as oxidation barrier for silicon based materials},
author = {Fiorentino, Giuseppe, E-mail: g.fiorentino@tudelft.nl and Morana, Bruno and Forte, Salvatore and Sarro, Pasqualina Maria},
abstractNote = {In this paper, the authors study the protective effect against oxidation of a thin layer of atomic layer deposited (ALD) aluminum oxide (Al{sub 2}O{sub 3}). Nitrogen doped silicon carbide (poly-SiC:N) based microheaters coated with ALD Al{sub 2}O{sub 3} are used as test structure to investigate the barrier effect of the alumina layers to oxygen and water vapor at very high temperature (up to 1000 °C). Different device sets have been fabricated changing the doping levels, to evaluate possible interaction between the dopants and the alumina layer. The as-deposited alumina layer morphology has been evaluated by means of AFM analysis and compared to an annealed sample (8 h at 1000 °C) to estimate the change in the grain structure and the film density. The coated microheaters are subjected to very long oxidation time in dry and wet environment (up to 8 h at 900 and 1000 °C). By evaluating the electrical resistance variation between uncoated reference devices and the ALD coated devices, the oxide growth on the SiC is estimated. The results show that the ALD alumina coating completely prevents the oxidation of the SiC up to 900 °C in wet environment, while an oxide thickness reduction of 50% is observed at 1000 °C compared to uncoated devices.},
doi = {10.1116/1.4904208},
journal = {Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films},
number = 1,
volume = 33,
place = {United States},
year = {Thu Jan 15 00:00:00 EST 2015},
month = {Thu Jan 15 00:00:00 EST 2015}
}
  • Zirconium oxide or zirconia (ZrO{sub 2})-based thermal barrier coatings (TBC) and aluminum oxide (Al{sub 2}O{sub 3}) layers were fabricated by detonation gun (D-gun) spraying. Al{sub 2}O{sub 3} layers with thicknesses of 50 {micro}m, 150 {micro}m, or 250 {micro}m were applied to a duplex TBC system as an intermediate layer or a surface layer, and their effects on the oxidation behavior of the TBC coatings were investigated at 1,200 C. Oxidation kinetics showed that the suitable application of Al{sub 2}O{sub 3} layers suppressed the oxidation of the Ni-Cr-Al-Y bond coat, and the oxidized rates were partially dependent on the thickness ofmore » the Al{sub 2}O{sub 3} layers. In the case of an Al{sub 2}O{sub 3} layer applied onto the surface, the durability and integrity of the TBC coatings were improved remarkably and the oxidation resistance was enhanced. However, a deteriorating spallation occurred for the specimens with an Al{sub 2}O{sub 3} intermediate layer thicker than 50 {micro}m. The main failure modes were identified based on microstructural analyses.« less
  • We report on our investigation of the electrical properties of metal/Al{sub 2}O{sub 3}/GaN metal-insulator-semiconductor capacitors. We determined the conduction band offset and interface charge density of the alumina/GaN interface by analyzing the capacitance-voltage characteristics of atomic layer deposited Al{sub 2}O{sub 3} films on GaN substrates. The conduction band offset at the Al{sub 2}O{sub 3}/GaN interface was calculated to be 2.13 eV, in agreement with theoretical predications. A non-zero field of 0.93 MV/cm in the oxide under flat-band conditions in the GaN was inferred, which we attribute to a fixed net positive charge density of magnitude 4.60 x 10{sup 12 }cm{supmore » -2} at the Al{sub 2}O{sub 3}/GaN interface. We provide hypotheses to explain the origin of this charge by analyzing the energy band line-up.« less
  • The fracture strength of Al{sub 2}O{sub 3} membranes deposited by atomic layer deposition at 110, 150, 200, and 300 °C was investigated. The fracture strength was found to be in the range of 2.25–3.00 GPa using Weibull statistics and nearly constant as a function of deposition temperature. This strength is superior to common microelectromechanical systems materials such as diamondlike carbon, SiO{sub 2}, or SiC. As-deposited membranes sustained high cycling pressure loads >10 bar/s without fracture. Films featured, however, significant reduction in the resistance to failure after annealing (800 °C) or high humidity (95%, 60 °C) treatments.
  • Atomic layer deposition (ALD) holds markedly high potential of becoming the enabling method for achieving the three-dimensional all-solid-state thin-film lithium ion battery (LiB). One of the most crucial components in such a battery is the electrolyte that needs to hold both low electronic conductivity and at least fair lithium ion conductivity being at the same time pinhole free. To obtain these desired properties in an electrolyte film, one necessarily has to have a good control over the elemental composition of the deposited material. The present study reports on the properties of ALD lithium aluminum oxide (Li{sub x}Al{sub y}O{sub z}) thinmore » films. In addition to LiB electrolyte applications, Li{sub x}Al{sub y}O{sub z} is also a candidate low dielectric constant (low-k) etch stop and diffusion barrier material in nanoelectronics applications. The Li{sub x}Al{sub y}O{sub z} films were deposited employing trimethylaluminum-O{sub 3} and lithium tert-butoxide-H{sub 2}O for Al{sub 2}O{sub 3} and Li{sub 2}O/LiOH, respectively. The composition was aimed to be controlled by varying the pulsing ratio of those two binary oxide ALD cycles. The films were characterized by several methods for composition, crystallinity and phase, electrical properties, hardness, porosity, and chemical environment. Regardless of the applied pulsing ratio of Al{sub 2}O{sub 3} and Li{sub 2}O/LiOH, all the studied ALD Li{sub x}Al{sub y}O{sub z} films of 200 and 400 nm in thickness were polycrystalline in the orthorhombic β-LiAlO{sub 2} phase and also very similar to each other with respect to composition and other studied properties. The results are discussed in the context of both fundamental ALD chemistry and applicability of the films as thin-film LiB electrolytes and low-k etch stop and diffusion barriers.« less