Inhibitive formation of nanocavities by introduction of Si atoms in Ge nanocrystals produced by ion implantation

Journal Article · Wed May 28 04:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4880661· OSTI ID:22304310

Cai, R. S.; Shang, L.; Liu, X. H.; Zhang, Y. J. ^[1]; Ross, G. G.

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1. The Cultivation Base for State Key Laboratory, Qingdao University, No. 308 Ningxia Road, Qingdao 266071 (China)

Germanium nanocrystals (Ge-nc) were successfully synthesized by co-implantation of Si and Ge ions into a SiO{sub 2} film thermally grown on (100) Si substrate and fused silica (pure SiO{sub 2}), respectively, followed by subsequent annealing at 1150 °C for 1 h. Transmission electron microscopy (TEM) examinations show that nanocavities only exist in the fused silica sample but not in the SiO{sub 2} film on a Si substrate. From the analysis of the high-resolution TEM images and electron energy-loss spectroscopy spectra, it is revealed that the absence of nanocavities in the SiO{sub 2} film/Si substrate is attributed to the presence of Si atoms inside the formed Ge-nc. Because the energy of Si-Ge bonds (301 kJ·mol{sup −1}) are greater than that of Ge-Ge bonds (264 kJ·mol{sup −1}), the introduction of the Si-Ge bonds inside the Ge-nc can inhibit the diffusion of Ge from the Ge-nc during the annealing process. However, for the fused silica sample, no crystalline Si-Ge bonds are detected within the Ge-nc, where strong Ge outdiffusion effects produce a great number of nanocavities. Our results can shed light on the formation mechanism of nanocavities and provide a good way to avoid nanocavities during the process of ion implantation.

• OSTI ID: 22304310
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 20 Vol. 115; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ANNEALING
CHEMICAL BONDS
DIFFUSION
ENERGY-LOSS SPECTROSCOPY
FILMS
GERMANIUM
GERMANIUM IONS
ION IMPLANTATION
NANOSTRUCTURES
PHYSICAL RADIATION EFFECTS
RESOLUTION
SILICON
SILICON OXIDES
SPECTRA
SUBSTRATES
TRANSMISSION ELECTRON MICROSCOPY
VISIBLE RADIATION