Growth of Boron Nanowires by Chemical Vapor Deposition

2007 ◽  
Vol 1017 ◽  
Author(s):  
Li Guo ◽  
Raj N. Singh
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Mechanisms ◽  
Nano Structures ◽  
Gas Chemistry ◽  
Potential Applications ◽  
Vls Growth ◽  
Boron Nanowires

AbstractMotivated by the extensive research on carbon nanotubes (CNTs), boron and its related nano-structures have attracted increasing interests for potential applications in nanodevices and nanotechnologies due to their extraordinary properties. B-related nanostructures are successfully grown on various substrates in a CVD process. The boron nanowires have diameters around 50-200 nanometers and lengths up to a few microns. The gas chemistry is monitored by the in-situ mass-spectroscopy, which helps to identify reactive species in the process. Modified vapor-solid growths as well as VLS growth mechanisms are proposed for the growth of these nanostructures. The role of the catalysts in the synthesis is also discussed.

scholarly journals Growth of Boron-Rich Nanowires by Chemical Vapor Deposition (CVD)

2006 ◽  
Vol 2006 ◽  
pp. 1-6 ◽  
Author(s):  
L. Guo ◽  
R. N. Singh ◽  
H. J. Kleebe
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Ni Catalyst ◽  
Nanowire Growth ◽  
Gas Chemistry ◽  
Inert Carrier ◽  
Gas Precursor

B-rich nanowires are grown on Ni coated oxidized Si(111) substrate using diborane as the gas precursor in a CVD process at 20 torr and900C∘. These nanowires have diameters around 20–100 nanometers and lengths up to microns. IcosahedronB12is shown to be the basic building unit forming the amorphous B-rich nanowires as characterized by EDAX, XRD, XPS, and Raman spectroscopies. The gas chemistry at low [B2H6]/ [N2] ratio is monitored by the in situ mass spectroscopy, which identifiedN2as an inert carrier gas leading to formation of the B-rich compounds. A nucleation controlled growth mechanism is proposed to explain the rugged nanowire growth of boron. The role of the Ni catalyst in the synthesis of the B-rich nanostructures is also discussed.

SiC Nanowires Grown on 4H-SiC Substrates by Chemical Vapor Deposition

2010 ◽  
Vol 645-648 ◽  
pp. 187-190 ◽  
Author(s):  
Bharat Krishnan ◽  
Siva Prasad Kotamraju ◽  
Siddarth G. Sundaresan ◽  
Yaroslav Koshka
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Metal Catalyst ◽  
X Ray Diffraction ◽  
Sic Nanowires ◽  
Vls Growth ◽  
Growth Experiments

Growth of SiC nanowires on commercial 4H-SiC substrates by chemical vapor deposition is reported. The main objective was to explore a possibility of reproducing the substrate polytype in order to obtain SiC NWs specifically composed of the hexagonal 4H-SiC polytype. The growth experiments were conducted in a hot-wall CVD reactor with H2 as the carrier gas, SiCl4 as the silicon source, and CH3Cl as the carbon source. Vapor-liquid-solid (VLS) growth mode was enabled by using metal nano-particle on the surface of the 4H-SiC substrates. Formation of nanowires or bigger nano-cones was achieved depending on the temperature and the metal catalyst used. Only SiC phase with no presence of Si was confirmed by X-ray diffraction for the growth temperatures down to 1050°C. The low temperature photoluminescence spectra measured on as-grown NWs showed clear 4H-SiC nitrogen bound excitons in some of the samples, particularly when in-situ N2 doping was used. The density of stacking faults detected by TEM strongly depended on the growth conditions.

scholarly journals Non-classical nucleation in vapor–liquid–solid growth of monolayer WS2 revealed by in-situ monitoring chemical vapor deposition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoming Qiang ◽  
Yuta Iwamoto ◽  
Aoi Watanabe ◽  
Tomoya Kameyama ◽  
Xing He ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Rapid Growth ◽  
Growth Dynamics ◽  
Chemical Vapor ◽  
In Situ Monitoring ◽  
Vapor Liquid Solid ◽  
Crystal Anisotropy ◽  
Vls Growth

AbstractThe very early nucleation stage of a transition metal dichalcogenide (TMD) was directly observed with in-situ monitoring of chemical vapor deposition and automated image analysis. Unique nucleation dynamics, such as very large critical nuclei and slow to rapid growth transitions, were observed during the vapor–liquid–solid (VLS) growth of monolayer tungsten disulfide (WS2). This can be explained by two-step nucleation, also known as non-classical nucleation, in which metastable clusters are formed through the aggregation of droplets. Subsequently, nucleation of solid WS2 takes place inside the metastable cluster. Furthermore, the detailed nucleation dynamics was systematically investigated from a thermodynamic point of view, revealing that the incubation time of metastable cluster formation follows the traditional time–temperature transformation diagram. Quantitative phase field simulation, combined with Bayesian inference, was conducted to extract quantitative information on the growth dynamics and crystal anisotropy from in-situ images. A clear transition in growth dynamics and crystal anisotropy between the slow and rapid growth phases was quantitatively verified. This observation supports the existence of two-step nucleation in the VLS growth of WS2. Such detailed understanding of TMD nucleation dynamics can be useful for achieving perfect structure control of TMDs.

In situ study of electron beam-induced chemical vapor deposition of Au in an environmental TEM

1995 ◽  
Vol 53 ◽  
pp. 256-257
Author(s):  
J. Drucker ◽  
R. Sharma ◽  
J. Kouvetakis ◽  
K.H.J. Weiss
Keyword(s):  
Electron Beam ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Quantum Effect ◽  
Line Drawing ◽  
Chemical Vapor ◽  
Environmental Cell ◽  
Engineering Changes ◽  
Kinetics Of

Patterning of metals is a key element in the fabrication of integrated microelectronics. For circuit repair and engineering changes constructive lithography, writing techniques, based on electron, ion or photon beam-induced decomposition of precursor molecule and its deposition on top of a structure have gained wide acceptance Recently, scanning probe techniques have been used for line drawing and wire growth of W on a silicon substrate for quantum effect devices. The kinetics of electron beam induced W deposition from WF6 gas has been studied by adsorbing the gas on SiO2 surface and measuring the growth in a TEM for various exposure times. Our environmental cell allows us to control not only electron exposure time but also the gas pressure flow and the temperature. We have studied the growth kinetics of Au Chemical vapor deposition (CVD), in situ, at different temperatures with/without the electron beam on highly clean Si surfaces in an environmental cell fitted inside a TEM column.

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