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Title: Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition

Abstract

We have investigated phase separation, silicon nanocrystal (Si NC) formation and optical properties of Si oxide (SiO{sub x}, 0<x<2) films by high-vacuum annealing and dry oxidation. The SiO{sub x} films were deposited by plasma-enhanced chemical vapor deposition at different nitrous-oxide/silane flow ratios. The physical and optical properties of the SiO{sub x} films were studied as a result of high-vacuum annealing and thermal oxidation. X-ray photoelectron spectroscopy (XPS) reveals that the as-deposited films have a random-bonding or continuous-random-network structure with different oxidation states. After annealing at temperatures above 1000 deg. C, the intermediate Si continuum in XPS spectra (referring to the suboxide) split to Si peaks corresponding to SiO{sub 2} and elemental Si. This change indicates the phase separation of the SiO{sub x} into more stable SiO{sub 2} and Si clusters. Raman, high-resolution transmission electron microscopy and optical absorption confirmed the phase separation and the formation of Si NCs in the films. The size of Si NCs increases with increasing Si concentration in the films and increasing annealing temperature. Two photoluminescence (PL) bands were observed in the films after annealing. The ultraviolet (UV)-range PL with a peak fixed at 370-380 nm is independent of Si concentration and annealing temperature, which ismore » a characteristic of defect states. Strong PL in red range shows redshifts from {approx}600 to 900 nm with increasing Si concentration and annealing temperature, which supports the quantum confinement model. After oxidation of the high-temperature annealed films, the UV PL was almost quenched while the red PL shows continuous blueshifts with increasing oxidation time. The different oxidation behaviors further relate the UV PL to the defect states and the red PL to the recombination of quantum-confined excitions.« less

Authors:
; ; ; ; ; ; ;  [1]
  1. Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)
Publication Date:
OSTI Identifier:
20664983
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 97; Journal Issue: 1; Other Information: DOI: 10.1063/1.1829789; (c) 2005 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; ABSORPTION; ANNEALING; CHEMICAL VAPOR DEPOSITION; CONFINEMENT; CRYSTAL DEFECTS; NANOSTRUCTURES; NITROUS OXIDE; OPTICAL PROPERTIES; OXIDATION; PHOTOLUMINESCENCE; PLASMA; RANDOMNESS; RECOMBINATION; SILICON OXIDES; SPECTRAL SHIFT; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; ULTRAVIOLET RADIATION; VALENCE; X-RAY PHOTOELECTRON SPECTROSCOPY

Citation Formats

Chen, X Y, Lu, Y F, Tang, L J, Wu, Y H, Cho, B J, Xu, X J, Dong, J R, Song, W D, Department of Electrical Engineering, University of Nebraska, Lincoln, Nebraska 68588-0511, Institute of Microelectronics, 11 Science Park Road, Singapore 117685, Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, and Data Storage Institute, 5 Engineering Drive 1, Singapore 117608. Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition. United States: N. p., 2005. Web. doi:10.1063/1.1829789.
Chen, X Y, Lu, Y F, Tang, L J, Wu, Y H, Cho, B J, Xu, X J, Dong, J R, Song, W D, Department of Electrical Engineering, University of Nebraska, Lincoln, Nebraska 68588-0511, Institute of Microelectronics, 11 Science Park Road, Singapore 117685, Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, & Data Storage Institute, 5 Engineering Drive 1, Singapore 117608. Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition. United States. https://doi.org/10.1063/1.1829789
Chen, X Y, Lu, Y F, Tang, L J, Wu, Y H, Cho, B J, Xu, X J, Dong, J R, Song, W D, Department of Electrical Engineering, University of Nebraska, Lincoln, Nebraska 68588-0511, Institute of Microelectronics, 11 Science Park Road, Singapore 117685, Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260, Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602, and Data Storage Institute, 5 Engineering Drive 1, Singapore 117608. 2005. "Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition". United States. https://doi.org/10.1063/1.1829789.
@article{osti_20664983,
title = {Annealing and oxidation of silicon oxide films prepared by plasma-enhanced chemical vapor deposition},
author = {Chen, X Y and Lu, Y F and Tang, L J and Wu, Y H and Cho, B J and Xu, X J and Dong, J R and Song, W D and Department of Electrical Engineering, University of Nebraska, Lincoln, Nebraska 68588-0511 and Institute of Microelectronics, 11 Science Park Road, Singapore 117685 and Department of Electrical and Computer Engineering, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 and Institute of Materials Research and Engineering, 3 Research Link, Singapore 117602 and Data Storage Institute, 5 Engineering Drive 1, Singapore 117608},
abstractNote = {We have investigated phase separation, silicon nanocrystal (Si NC) formation and optical properties of Si oxide (SiO{sub x}, 0<x<2) films by high-vacuum annealing and dry oxidation. The SiO{sub x} films were deposited by plasma-enhanced chemical vapor deposition at different nitrous-oxide/silane flow ratios. The physical and optical properties of the SiO{sub x} films were studied as a result of high-vacuum annealing and thermal oxidation. X-ray photoelectron spectroscopy (XPS) reveals that the as-deposited films have a random-bonding or continuous-random-network structure with different oxidation states. After annealing at temperatures above 1000 deg. C, the intermediate Si continuum in XPS spectra (referring to the suboxide) split to Si peaks corresponding to SiO{sub 2} and elemental Si. This change indicates the phase separation of the SiO{sub x} into more stable SiO{sub 2} and Si clusters. Raman, high-resolution transmission electron microscopy and optical absorption confirmed the phase separation and the formation of Si NCs in the films. The size of Si NCs increases with increasing Si concentration in the films and increasing annealing temperature. Two photoluminescence (PL) bands were observed in the films after annealing. The ultraviolet (UV)-range PL with a peak fixed at 370-380 nm is independent of Si concentration and annealing temperature, which is a characteristic of defect states. Strong PL in red range shows redshifts from {approx}600 to 900 nm with increasing Si concentration and annealing temperature, which supports the quantum confinement model. After oxidation of the high-temperature annealed films, the UV PL was almost quenched while the red PL shows continuous blueshifts with increasing oxidation time. The different oxidation behaviors further relate the UV PL to the defect states and the red PL to the recombination of quantum-confined excitions.},
doi = {10.1063/1.1829789},
url = {https://www.osti.gov/biblio/20664983}, journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 1,
volume = 97,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2005},
month = {Sat Jan 01 00:00:00 EST 2005}
}