Jpn. J. Appl. Phys. 50 (2011) 01BF04 (4 pages)  |Previous Article| |Next Article|  |Table of Contents|
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Annealing Effects on Cathodoluminescence Properties of SiO_x Films Deposited by Radio Frequency Sputtering

Ahmed Mohamed Ahmed Abd El-Razek Shamekh¹, Norio Tokuda, and Takao Inokuma

(Received June 25, 2010; accepted October 21, 2010; published online January 20, 2011)

The effects of high-temperature thermal annealing on cathodoluminescence (CL) spectra in SiO_x (0.9 ≤x ≤1.87) films prepared by radio-frequency sputtering are investigated. The CL intensities for the as-deposited films are weak but they increase after thermal annealing at 900 and 1100 °C. One of features in the CL spectra for the films annealed at 1100 °C is a peak at a photon energy of ∼2.7 eV with an asymmetric tail on the lower energy side. In order to analyze the spectral features, optical transition energies are calculated for Si_n clusters with n = 2–5, embedded in a SiO_x matrix, by ab initio molecular orbital calculation. In addition, the probabilities of formation are statistically estimated for those Si clusters under the assumption of a chemically ordered random network for the SiO_x network. The comparison of the experimental results with the calculated transition energies and the statistics of the Si clusters suggests that a contribution of the Si₂ clusters to the CL spectra are dominant, whereas those of the Si_n clusters with n > 3 are considerably small.

URL: http://jjap.jsap.jp/link?JJAP/50/01BF04/
DOI: 10.1143/JJAP.50.01BF04
PACS: 81.15.Cd, 78.60.Hk, 78.66.Jg, 71.15.Ap

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