Nanocrystalline-Si-dot multi-layers fabrication by chemical vapor deposition with H-plasma surface treatment and evaluation of structure and quantum confinement effects

Journal Article · Wed Jan 15 00:00:00 EST 2014 · AIP Advances

DOI:https://doi.org/10.1063/1.4864055· OSTI ID:22251593

Kosemura, Daisuke; Mizukami, Yuki; Takei, Munehisa; Numasawa, Yohichiroh; Ogura, Atsushi ^[1]; Ohshita, Yoshio ^[2]

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1. School of Science and Technology, Meiji University, Kawasaki 214-8571 (Japan)
2. Toyota Technological Institute, Nagoya 468-8511 (Japan)

100-nm-thick nanocrystalline silicon (nano-Si)-dot multi-layers on a Si substrate were fabricated by the sequential repetition of H-plasma surface treatment, chemical vapor deposition, and surface oxidation, for over 120 times. The diameter of the nano-Si dots was 5–6 nm, as confirmed by both the transmission electron microscopy and X-ray diffraction analysis. The annealing process was important to improve the crystallinity of the nano-Si dot. We investigated quantum confinement effects by Raman spectroscopy and photoluminescence (PL) measurements. Based on the experimental results, we simulated the Raman spectrum using a phenomenological model. Consequently, the strain induced in the nano-Si dots was estimated by comparing the experimental and simulated results. Taking the estimated strain value into consideration, the band gap modulation was measured, and the diameter of the nano-Si dots was calculated to be 5.6 nm by using PL. The relaxation of the q ∼ 0 selection rule model for the nano-Si dots is believed to be important to explain both the phenomena of peak broadening on the low-wavenumber side observed in Raman spectra and the blue shift observed in PL measurements.

• OSTI ID: 22251593
• Journal Information: AIP Advances, Vol. 4, Issue 1; Other Information: (c) 2014 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
CHEMICAL VAPOR DEPOSITION
CRYSTALS
FABRICATION
LAYERS
NANOSTRUCTURES
OXIDATION
PHOTOLUMINESCENCE
PLASMA
RAMAN SPECTRA
RAMAN SPECTROSCOPY
SELECTION RULES
SILICON
SIMULATION
STRAINS
SUBSTRATES
SURFACE TREATMENTS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION