Epitaxial Growth of Single Crystalline Ge Films on GaAs Substrates for CMOS Device Integration

ABSTRACTWe report a novel chemical vapor deposition (CVD) process for epitaxial growth of Ge film on GaAs substrate. The resultant layer exhibits device level quality, as shown by high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, high-resolution X-ray diffraction (HRXRD). In addition, atomic force microscopy (AFM) scanning indicates low RMS surface roughness of 5 Å. Secondary ion mass spectrometry (SIMS) reveals negligible out-diffusion of Ga and As into the Ge epilayer. By employing silane passivation, Ge p-MOSFET with TaN/HfO2 gate stack was fabricated on Ge/GaAs heterostructure for the first time, showing excellent output and pinch-off characteristics. A GaAs channel n-MOSFET was also fabricated, using similar SiH4 treatment during gate stack formation. These results reveal a potential solution to integrate Ge p-channel and GaAs n-channel MOSFET for advanced CMOS applications.

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Epitaxial Growth and Characterization of the Ordered Vacancy Compound CuIn3Se5 on GaAs (100) Fabricated by Molecular Beam Epitaxy

MRS Proceedings ◽

10.1557/proc-340-599 ◽

1994 ◽

Vol 340 ◽

Cited By ~ 1

Author(s):

Art J. Nelson ◽

M. Bode ◽

G. Horner ◽

K. Sinha ◽

John Moreland

Keyword(s):

Molecular Beam Epitaxy ◽

Epitaxial Growth ◽

Molecular Beam ◽

Structural Defects ◽

X Ray Diffraction ◽

Symmetric Vibration ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron

ABSTRACTEpitaxial growth of the ordered vacancy compound (OVC) CuIn3Se5 has been achieved on GaAs (100) by molecular beam epitaxy (MBE) from Cu2Se and In2Se3 sources. Electron probe microanalysis and X-ray diffraction have confirmed the composition for the 1-3-5 OVC phase and that the film is single crystal Culn3Se5 (100). Transmission electron microscopy (TEM) characterization of the material also showed it to be single crystalline. Structural defects in the layer consisted mainly of stacking faults. Photoluminescence (PL) measurements performed at 7.5 K indicate that the bandgap is 1.28 eV. Raman spectra reveal a strong polarized peak at 152 cm−1, which is believed to arise from the totally symmetric vibration of the Se atoms in the lattice. Atomic force microscopy reveals faceting in a preferred (100) orientation.

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HETERO-GROWTH OF (100) ORIENTATED ZNO FILMS ON SILICON BY SS-CVD

International Journal of Modern Physics B ◽

10.1142/s0217979202015194 ◽

2002 ◽

Vol 16 (28n29) ◽

pp. 4250-4254 ◽

Cited By ~ 1

Author(s):

JIAN-GUO LU ◽

ZHI-ZHEN YE ◽

HAN-HONG CHEN ◽

JING-YUN HUANG ◽

BING-HUI ZHAO

Keyword(s):

Texture Coefficient ◽

Zinc Acetate Dihydrate ◽

Chemical Vapor ◽

Zno Films ◽

X Ray Diffraction ◽

Lower Growth ◽

Force Microscopy ◽

Atomic Force ◽

First Time ◽

Lower Growth Temperature

ZnO films with (100) preferred orientation are reported for the first time. ZnO films were synthesized on Si(100) substrate by solid-source chemical vapor deposition (SS-CVD) using zinc acetate dihydrate (solid) as a precursor. The structural properties were investigated by X-ray diffraction and atomic force microscopy. Results show that a lower growth temperature and a higher deposition rate will facilitate the formation of (100) texture. The texture coefficient for (100) plane is 3.28.

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On the Study of Dislocation Density in MBE GaSb-Based Structures

Crystals ◽

10.3390/cryst10121074 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1074

Author(s):

Agata Jasik ◽

Dariusz Smoczyński ◽

Iwona Sankowska ◽

Andrzej Wawro ◽

Jacek Ratajczak ◽

...

Keyword(s):

High Resolution ◽

Dislocation Density ◽

Measurement Techniques ◽

Threading Dislocation ◽

X Ray Diffraction ◽

Gaas Sample ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Threading Dislocation Density

The results of the study on threading dislocation density (TDD) in homo- and heteroepitaxial GaSb-based structures (metamorphic layers, material grown by applying interfacial misfit array (IMF) and complex structures) deposited using molecular beam epitaxy are presented. Three measurement techniques were considered: high-resolution x-ray diffraction (HRXRD), etch pit density (EPD), and counting tapers on images obtained using atomic force microscopy (AFM). Additionally, high-resolution transmission electron microscopy (HRTEM) was used for selected samples. The density of dislocations determined using these methods varied, e.g., for IMF-GaSb/GaAs sample, were 6.5 × 108 cm−2, 2.2 × 106 cm−2, and 4.1 × 107 cm−2 obtained using the HRXRD, EPD, and AFM techniques, respectively. Thus, the value of TDD should be provided together with information about the measurement method. Nevertheless, the absolute value of TDD is not as essential as the credibility of the technique used for optimizing material growth. By testing material groups with known parameters, we established which techniques can be used for examining the dislocation density in GaSb-based structures.

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Growth of Ultra-High Density 3C-SiC Nanowires via Single Source CVD

MRS Proceedings ◽

10.1557/opl.2011.1207 ◽

2011 ◽

Vol 1350 ◽

Cited By ~ 3

Author(s):

Kasif Teker ◽

Joseph A. Oxenham

Keyword(s):

Electron Microscopy ◽

Chemical Vapor ◽

Iron Film ◽

X Ray Diffraction ◽

Lower Efficiency ◽

Force Microscopy ◽

High Temperature Electronics ◽

Sic Nanowires ◽

Atomic Force ◽

Transmission Electron

ABSTRACTSilicon carbide (SiC) nanostructures attract interest due to their applications in optoelectronic devices, sensors, and high-power/high temperature electronics. The synthesis of SiC nanowires by chemical vapor deposition using hexamethyldisilane (HMDS) as a source material on SiO2/Si substrate has been investigated. Various catalyst materials, including iron (film and nanoparticles), nickel (film and nanoparticles), and cobalt nanoparticles have been used. The growth runs have been carried out at temperatures between 900 and 1100°C under H2 as carrier gas. 3C-SiC nanowires have successfully been grown at even lower temperatures despite the lower efficiency of source decomposition at low temperatures. The SiC nanowire diameters are in the range of 8 nm to 60 nm, as determined by transmission electron microscopy (TEM). In general, the efficiency of nanowire growth has increased with temperature except the growth on Ni film, which has occasionally resulted in SiC flowers. Higher nanowire density at high temperatures can be attributed to more efficient decomposition of the source at higher temperatures. Further, optical properties of the nanowires have been studied by Fourier transform infrared spectroscopy (FTIR). The fabricated nanowires have also been characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray diffraction (XRD).

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Fabrication and Characterization of Stacked Self-Assembled In0.5Ga0.5As/GaAs Quantum Dots Grown by MOCVD

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.896.215 ◽

2014 ◽

Vol 896 ◽

pp. 215-218

Author(s):

Didik Aryanto ◽

Zulkafli Othaman ◽

A. Khamim Ismail

Keyword(s):

Quantum Dots ◽

Chemical Vapor ◽

Organic Chemical ◽

X Ray Diffraction ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Metal Organic ◽

Self Assembled

Stacked self-assembled In0.5Ga0.5As/GaAs quantum dots (QDs) were grown using metal organic chemical vapor deposition (MOCVD). Atomic force microscopy (AFM), transmission electron microscopy (TEM) and high resolution X-ray diffraction (HR-XDR) show the effects of stacking on morphology and structure of QDs. Strains due to the buried QDs affect the shape and alignment of the successive layers. Capping of these QDs also determine the quality of the top most QDs structure.

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The effect of periodic silane burst on the properties of GaN on Si (111) substrates

MRS Proceedings ◽

10.1557/proc-831-e3.33 ◽

2004 ◽

Vol 831 ◽

Author(s):

K. Y. Zang ◽

S. J. Chua ◽

C. V. Thompson ◽

L. S. Wang ◽

S. Tripathy ◽

...

Keyword(s):

Chemical Vapor ◽

Buffer Layers ◽

Threading Dislocation ◽

X Ray Diffraction ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Dislocation Densities ◽

Gan On Si ◽

Aln Buffer

ABSTRACTThe periodic silane burst technique was employed during metalorganic chemical vapor deposition of epitaxial GaN on AlN buffer layers grown on Si (111). Periodic silicon delta doping during growth of both the AlN and GaN layers led to growth of GaN films with decreased tensile stresses and decreased threading dislocation densities, as well as films with improved quality as indicated by x-ray diffraction, micro-Raman spectroscopy, atomic force microscopy, and transmission electron microscopy. The possible mechanism of the reduction of tensile stress and the dislocation density is discussed in the paper.

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Synthesis and Characterization of Nitrogen-doped Carbon Nanotubes Derived from g-C3N4

Materials ◽

10.3390/ma13061349 ◽

2020 ◽

Vol 13 (6) ◽

pp. 1349 ◽

Cited By ~ 2

Author(s):

Klaudia Maślana ◽

Ryszard J. Kaleńczuk ◽

Beata Zielińska ◽

Ewa Mijowska

Keyword(s):

Carbon Nanotubes ◽

Chemical Vapor ◽

X Ray Diffraction ◽

X Ray ◽

Force Microscopy ◽

Nitrogen Doped ◽

Atomic Force ◽

Transmission Electron ◽

Nitrogen Doped Carbon

Here, nitrogen-doped carbon nanotubes (CNT-N) were synthesized using exfoliated graphitic carbon nitride functionalized with nickel oxides (ex-g-C3N4-NixOy). CNT-N were produced at 900 °C in two steps: (1) ex-g-C3N4-NixOy reduction with hydrogen and (2) ethylene assisted chemical vapor deposition (CVD). The detailed characterization of the produced materials was performed via atomic force microscopy (AFM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The possible mechanism of nanotubes formation is also proposed.

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A Comparative Study of the Synthesis of Carbon Nanotubes Using Ni and Fe as Catalyst

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.67.89 ◽

2009 ◽

Vol 67 ◽

pp. 89-94 ◽

Cited By ~ 1

Author(s):

Joydip Sengupta ◽

Sovan Kumar Panda ◽

Chacko Jacob

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Chemical Vapor ◽

X Ray Diffraction ◽

Raman Spectroscopic ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Pressure Chemical ◽

Synthesis Of Carbon Nanotubes

The effect of Fe and Ni catalysts on the synthesis of carbon nanotubes (CNTs) using atmospheric pressure chemical vapor deposition (APCVD) was investigated. Distribution of the catalyst particles over the Si substrate was analyzed by atomic force microscopy (AFM). Characterization by X-ray diffraction analysis (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM) and Raman spectroscopic measurements over the grown species is reported. The study clearly shows that the catalyst strongly influences morphology and microstructure of the grown CNTs.

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Structural and Optical Properties of InAsSbBi Grown by Molecular Beam Epitaxy on Offcut GaSb Substrates

Photonics ◽

10.3390/photonics8060215 ◽

2021 ◽

Vol 8 (6) ◽

pp. 215

Author(s):

Rajeev R. Kosireddy ◽

Stephen T. Schaefer ◽

Marko S. Milosavljevic ◽

Shane R. Johnson

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Optical Quality ◽

X Ray Diffraction ◽

Interface Quality ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Lateral Variations

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.

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High resolution nanoscale chemical analysis of bitumen surface microstructures

Scientific Reports ◽

10.1038/s41598-021-92835-3 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ayse N. Koyun ◽

Julia Zakel ◽

Sven Kayser ◽

Hartmut Stadler ◽

Frank N. Keutsch ◽

...

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Force Microscopy ◽

Photo Oxidation ◽

Atomic Force ◽

Para Phase ◽

Key Sites ◽

Respective Surface ◽

Surface Domains ◽

Surface Microstructures ◽

First Time

AbstractSurface microstructures of bitumen are key sites in atmospheric photo-oxidation leading to changes in the mechanical properties and finally resulting in cracking and rutting of the material. Investigations at the nanoscale remain challenging. Conventional combination of optical microscopy and spectroscopy cannot resolve the submicrostructures due to the Abbe restriction. For the first time, we report here respective surface domains, namely catana, peri and para phases, correlated to distinct molecules using combinations of atomic force microscopy with infrared spectroscopy and with correlative time of flight—secondary ion mass spectrometry. Chemical heterogeneities on the surface lead to selective oxidation due to their varying susceptibility to photo-oxidation. It was found, that highly oxidized compounds, are preferentially situated in the para phase, which are mainly asphaltenes, emphasising their high oxidizability. This is an impressive example how chemical visualization allows elucidation of the submicrostructures and explains their response to reactive oxygen species from the atmosphere.

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