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Title: Evolution of the electrical and structural properties during the growth of Al doped ZnO films by remote plasma-enhanced metalorganic chemical vapor deposition

Abstract

Al-doped zinc oxide (AZO) films were deposited by means of remote plasma-enhanced metalorganic chemical vapor deposition from oxygen/diethylzinc/trimethylaluminum mixtures. The electrical, structural (crystallinity and morphology), and chemical properties of the deposited films were investigated using Hall, four point probe, x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), electron recoil detection (ERD), Rutherford backscattering (RBS), and time of flight secondary ion mass spectrometry (TOF-SIMS), respectively. We found that the working pressure plays an important role in controlling the sheet resistance R{sub s} and roughness development during film growth. At 1.5 mbar the AZO films are highly conductive (R{sub s}<6 {omega}/{open_square} for a film thickness above 1200 nm) and very rough (>4% of the film thickness), however, they are characterized by a large sheet resistance gradient with increasing film thickness. By decreasing the pressure from 1.5 to 0.38 mbar, the gradient is significantly reduced and the films become smoother, but the sheet resistance increases (R{sub s}{approx_equal}100 {omega}/{open_square} for a film thickness of 1000 nm). The sheet resistance gradient and the surface roughness development correlate with the grain size evolution, as determined from the AFM and SEM analyses, indicating the transition from pyramid-like at 1.5 mbar to pillar-like growth modemore » at 0.38 mbar. The change in plasma chemistry/growth precursors caused by the variation in pressure leads to different concentration and activation efficiency of Al dopant in the zinc oxide films. On the basis of the experimental evidence, a valid route for further improving the conductivity of the AZO film is found, i.e., increasing the grain size at the initial stage of film growth.« less

Authors:
; ;
Publication Date:
OSTI Identifier:
21057504
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 102; Journal Issue: 4; Other Information: DOI: 10.1063/1.2772569; (c) 2007 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; ALUMINIUM; ATOMIC FORCE MICROSCOPY; CHEMICAL PROPERTIES; CHEMICAL VAPOR DEPOSITION; CRYSTAL GROWTH; DOPED MATERIALS; ELECTRIC CONDUCTIVITY; GRAIN SIZE; HALL EFFECT; ION MICROPROBE ANALYSIS; MASS SPECTROSCOPY; ROUGHNESS; RUTHERFORD BACKSCATTERING SPECTROSCOPY; SCANNING ELECTRON MICROSCOPY; SEMICONDUCTOR MATERIALS; THICKNESS; THIN FILMS; TIME-OF-FLIGHT METHOD; X-RAY DIFFRACTION; ZINC OXIDES

Citation Formats

Volintiru, I, Creatore, M, Kniknie, B J, Spee, C. I. M. A., Sanden, M. C. M. van de, TNO Science and Industry, Materials Technology, P.O. Box 6235, 5600 HE Eindhoven, and Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven. Evolution of the electrical and structural properties during the growth of Al doped ZnO films by remote plasma-enhanced metalorganic chemical vapor deposition. United States: N. p., 2007. Web. doi:10.1063/1.2772569.
Volintiru, I, Creatore, M, Kniknie, B J, Spee, C. I. M. A., Sanden, M. C. M. van de, TNO Science and Industry, Materials Technology, P.O. Box 6235, 5600 HE Eindhoven, & Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven. Evolution of the electrical and structural properties during the growth of Al doped ZnO films by remote plasma-enhanced metalorganic chemical vapor deposition. United States. https://doi.org/10.1063/1.2772569
Volintiru, I, Creatore, M, Kniknie, B J, Spee, C. I. M. A., Sanden, M. C. M. van de, TNO Science and Industry, Materials Technology, P.O. Box 6235, 5600 HE Eindhoven, and Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven. 2007. "Evolution of the electrical and structural properties during the growth of Al doped ZnO films by remote plasma-enhanced metalorganic chemical vapor deposition". United States. https://doi.org/10.1063/1.2772569.
@article{osti_21057504,
title = {Evolution of the electrical and structural properties during the growth of Al doped ZnO films by remote plasma-enhanced metalorganic chemical vapor deposition},
author = {Volintiru, I and Creatore, M and Kniknie, B J and Spee, C. I. M. A. and Sanden, M. C. M. van de and TNO Science and Industry, Materials Technology, P.O. Box 6235, 5600 HE Eindhoven and Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven},
abstractNote = {Al-doped zinc oxide (AZO) films were deposited by means of remote plasma-enhanced metalorganic chemical vapor deposition from oxygen/diethylzinc/trimethylaluminum mixtures. The electrical, structural (crystallinity and morphology), and chemical properties of the deposited films were investigated using Hall, four point probe, x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), electron recoil detection (ERD), Rutherford backscattering (RBS), and time of flight secondary ion mass spectrometry (TOF-SIMS), respectively. We found that the working pressure plays an important role in controlling the sheet resistance R{sub s} and roughness development during film growth. At 1.5 mbar the AZO films are highly conductive (R{sub s}<6 {omega}/{open_square} for a film thickness above 1200 nm) and very rough (>4% of the film thickness), however, they are characterized by a large sheet resistance gradient with increasing film thickness. By decreasing the pressure from 1.5 to 0.38 mbar, the gradient is significantly reduced and the films become smoother, but the sheet resistance increases (R{sub s}{approx_equal}100 {omega}/{open_square} for a film thickness of 1000 nm). The sheet resistance gradient and the surface roughness development correlate with the grain size evolution, as determined from the AFM and SEM analyses, indicating the transition from pyramid-like at 1.5 mbar to pillar-like growth mode at 0.38 mbar. The change in plasma chemistry/growth precursors caused by the variation in pressure leads to different concentration and activation efficiency of Al dopant in the zinc oxide films. On the basis of the experimental evidence, a valid route for further improving the conductivity of the AZO film is found, i.e., increasing the grain size at the initial stage of film growth.},
doi = {10.1063/1.2772569},
url = {https://www.osti.gov/biblio/21057504}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 4,
volume = 102,
place = {United States},
year = {Wed Aug 15 00:00:00 EDT 2007},
month = {Wed Aug 15 00:00:00 EDT 2007}
}