Self-limiting low-temperature growth of crystalline AlN thin films by plasma-enhanced atomic layer deposition

Date
2012
Advisor
Instructor
Source Title
Thin Solid Films
Print ISSN
0040-6090
Electronic ISSN
Publisher
Volume
520
Issue
7
Pages
2750 - 2755
Language
English
Type
Article
Journal Title
Journal ISSN
Volume Title
Abstract

We report on the self-limiting growth and characterization of aluminum nitride (AlN) thin films. AlN films were deposited by plasma-enhanced atomic layer deposition on various substrates using trimethylaluminum (TMA) and ammonia (NH 3). At 185 °C, deposition rate saturated for TMA and NH 3 doses starting from 0.05 and 40 s, respectively. Saturative surface reactions between TMA and NH 3 resulted in a constant growth rate of ∼ 0.86 Å/cycle from 100 to 200 °C. Within this temperature range, film thickness increased linearly with the number of deposition cycles. At higher temperatures (≤ 225 °C) deposition rate increased with temperature. Chemical composition and bonding states of the films deposited at 185 °C were investigated by X-ray photoelectron spectroscopy. High resolution Al 2p and N 1s spectra confirmed the presence of AlN with peaks located at 73.02 and 396.07 eV, respectively. Films deposited at 185 °C were polycrystalline with a hexagonal wurtzite structure regardless of the substrate selection as determined by grazing incidence X-ray diffraction. High-resolution transmission electron microscopy images of the AlN thin films deposited on Si (100) and glass substrates revealed a microstructure consisting of nanometer sized crystallites. Films exhibited an optical band edge at ∼ 5.8 eV and an optical transmittance of > 95% in the visible region of the spectrum. © 2011 Elsevier B.V. All rights reserved.

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Keywords
Aluminum nitride, Atomic layer deposition, Self-limiting growth, Thin film, Trimethylaluminum, Wurtzite, AlN, AlN films, AlN thin films, Atomic layer, Bonding state, Chemical compositions, Constant growth rates, Deposition cycles, Glass substrates, Grazing incidence X-ray diffraction, Hexagonal wurtzite structure, High resolution, Higher temperatures, Low temperature growth, Nanometer-sized crystallites, Optical bands, Plasma-enhanced atomic layer deposition, Polycrystalline, Si(1 0 0), Substrate selection, Temperature range, Trimethylaluminum, Various substrates, Visible region, Wurtzites, Aluminum, Aluminum coatings, Aluminum nitride, Atomic layer deposition, Atoms, Deposition, Deposition rates, High resolution transmission electron microscopy, Nitrides, Plasma deposition, Semiconducting silicon compounds, Substrates, Surface reactions, Thin films, Transmission electron microscopy, Vapor deposition, X ray diffraction, X ray photoelectron spectroscopy, Zinc sulfide, Optical films
Citation
Published Version (Please cite this version)