Correlation of TEM data with confined phonons to determine strain and size of Ge nanocrystals embedded in SixNy matrix

AbstractGe is deposited on HfO2 surfaces by chemical vapor deposition (CVD) with GeH4. 0.7-1.0 ML GeHx (x = 0-3) is deposited by thermally cracking GeH4 on a hot tungsten filament. Ge oxidation and bonding are studied at 300-1000 K with X-ray photoelectron spectroscopy (XPS). Ge, GeH, GeO, and GeO2 desorption are measured with temperature programmed desorption (TPD) at 400-1000 K. Ge initially reacts with the dielectric forming an oxide layer followed by Ge deposition and formation of nanocrystals in CVD at 870 K. 0.7-1.0 ML GeHx deposited by cracking rapidly forms a contacting oxide layer on HfO2 that is stable from 300-800 K. Ge is fully removed from the HfO2 surface after annealing to 1000 K. These results help explain the stability of Ge nanocrystals in contact with HfO2.

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Effect of Quantum Confinement on Optical Properties of Ge Nanocrystals in GeO[sub 2] Films

Semiconductors ◽

10.1134/1.2085265 ◽

2005 ◽

Vol 39 (10) ◽

pp. 1168 ◽

Cited By ~ 44

Author(s):

E. B. Gorokhov

Keyword(s):

Optical Properties ◽

Quantum Confinement ◽

Ge Nanocrystals

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Preparation and photoluminescence properties of Ge nanocrystals embedded in Lu2O3 matrices with a Ge–GeOx core–shell structure

Physica B Condensed Matter ◽

10.1016/j.physb.2008.07.045 ◽

2008 ◽

Vol 403 (21-22) ◽

pp. 3997-3999 ◽

Cited By ~ 2

Author(s):

W. Wang ◽

R.S. Wu ◽

C.L. Yuan

Keyword(s):

Shell Structure ◽

Core Shell ◽

Photoluminescence Properties ◽

Core Shell Structure ◽

Ge Nanocrystals

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Charge trapping and retention behaviors of Ge nanocrystals distributed in the gate oxide near the gate synthesized by low-energy ion implantation

Journal of Applied Physics ◽

10.1063/1.2749470 ◽

2007 ◽

Vol 101 (12) ◽

pp. 124313 ◽

Cited By ~ 14

Author(s):

M. Yang ◽

T. P. Chen ◽

J. I. Wong ◽

C. Y. Ng ◽

Y. Liu ◽

...

Keyword(s):

Ion Implantation ◽

Charge Trapping ◽

Gate Oxide ◽

Low Energy ◽

Ge Nanocrystals

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Characterization of Ge nanocrystals in a-SiO2 synthesized by rapid thermal annealing

Applied Surface Science ◽

10.1016/s0169-4332(98)00908-8 ◽

1999 ◽

Vol 144-145 ◽

pp. 697-701 ◽

Cited By ~ 24

Author(s):

W.K Choi ◽

S Kanakaraju ◽

Z.X Shen ◽

W.S Li

Keyword(s):

Thermal Annealing ◽

Rapid Thermal Annealing ◽

Ge Nanocrystals

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Characterization and Manipulation of Exposed Ge Nanocrystals

MRS Proceedings ◽

10.1557/proc-818-m13.3.1 ◽

2004 ◽

Vol 818 ◽

Cited By ~ 2

Author(s):

I.D. Sharp ◽

Q. Xu ◽

C.Y. Liao ◽

D.O. Yi ◽

J.W. Ager ◽

...

Keyword(s):

Hydrofluoric Acid ◽

Metal Films ◽

Silica Matrix ◽

Size Distributions ◽

Si Substrates ◽

Atomic Force ◽

Transmission Electron ◽

Oxide Matrix ◽

Ge Nanocrystals

AbstractIsotopically pure 70Ge and 74Ge nanocrystals embedded in SiO2 thin films on Si substrates have been fabricated through ion implantation and thermal annealing. Nanocrystals were subsequently exposed using a hydrofluoric acid etching procedure to selectively remove the oxide matrix while retaining up to 69% of the implanted Ge. Comparison of transmission electron micrographs (TEM) of as-grown crystals to atomic force microscope (AFM) data of exposed crystals reveals that the nanocrystal size distribution is very nearly preserved during etching. Therefore, this process provides a new means to use AFM for rapid and straightforward determination of size distributions of nanocrystals formed in a silica matrix. Once exposed, nanocrystals may be transferred to a variety of substrates, such as conducting metal films and optically transparent insulators for further characterization.

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Development of Ge Nanoparticles Embedded in GeO2 Matrix

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2008.an04 ◽

2008 ◽

Vol 8 (8) ◽

pp. 4081-4085 ◽

Cited By ~ 3

Author(s):

Y. Batra ◽

D. Kabiraj ◽

D. Kanjilal

Keyword(s):

Electron Microscopy ◽

Annealing Temperature ◽

Spectroscopic Studies ◽

Electron Beam Evaporation ◽

Granular Structure ◽

Raman Analysis ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Ge Nanocrystals

Germanium (Ge) nanoparticles have attracted a lot of attention due to their excellent optical properties. In this paper, we report on the formation of Ge nanoparticles embedded in GeO2 matrix prepared by electron beam evaporation and subsequent annealing. Transmission electron microscopy (TEM) studies clearly indicate the formation of Ge nanocrystals in the films annealed at 500 °C. Fourier transform infrared (FTIR) spectroscopic studies are carried out to verify the evolution of the structure after annealingat each stage. Micro-Raman analysis also confirms the formation of Ge nanoparticles in the annealed films. Development of Ge nanoparticles is also established by photoluminescence (PL) analysis. Surface morphology study is carried out by atomic force microscopy (AFM). It shows the evolution of granular structure of the films with increasing annealing temperature.

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