Effect of growth conditions on the composition and structure of Si1−xGex nanowires grown by vapor–liquid–solid growth

2006 ◽  
Vol 21 (11) ◽  
pp. 2876-2881 ◽  
Author(s):  
Kok-Keong Lew ◽  
Ling Pan ◽  
Elizabeth C. Dickey ◽  
Joan M. Redwing
Keyword(s):  
Composition Range ◽  
Thin Film Deposition ◽  
Growth Conditions ◽  
Film Deposition ◽  
Vapor Liquid Solid ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Nanowire Surface ◽  
Gas Ratio ◽  
Vapor Liquid

The effect of growth conditions on the composition and structure of Si1−xGex nanowires grown by the vapor–liquid–solid method using gaseous precursors (SiH4 and GeH4) was investigated. Transmission electron microscopy was used to characterize the structural properties and elemental composition of the nanowires. At higher growth temperatures (>425 °C), Ge thin film deposition on the nanowire surface resulted in Au loss during growth and the formation of tapered structures. By simultaneously reducing the growth temperature from 425 to 325 °C to suppress the rate of Ge film deposition and increasing the GeH4/(GeH4 + SiH4) gas ratio, Si1−xGex nanowires were produced with Ge fractions spanning the entire composition range. The Ge fraction follows that predicted from the elemental nanowire growth rates in the Ge-rich (x > 0.5) regime, but deviates to higher Ge fractions in Si-rich (x < 0.5) nanowires. A mechanism was proposed whereby surface diffusion provides an additional pathway to Ge incorporation in Si-rich Si1−xGex nanowires.

Growth of AlN and TiN Structures by Plasma-Enhanced Pulsed Laser Deposition

2000 ◽  
Vol 648 ◽  
Author(s):  
Edward Poindexter ◽  
Yan Xin ◽  
Steven M. Durbin
Keyword(s):  
Electron Microscopy ◽  
Single Crystal ◽  
Plasma Source ◽  
Thin Film Deposition ◽  
Growth Conditions ◽  
High Energy ◽  
Film Deposition ◽  
Rf Plasma ◽  
Nitrogen Species ◽  
Active Nitrogen

AbstractNitride materials are of interest for a wide variety of applications, including wear-resistant coatings, insulating layers, high-temperature semiconductor devices, and short-wavelength emitters and detectors. TiN and AlN appear to be particularly amenable to crystalline thin film deposition, with stoichiometric material easily obtained even without the use of active nitrogen species. This paper describes the growth of crystalline AlN and TiN thin films on silicon and sapphire substrates using a KrF excimer laser (λ = 248 nm) to ablate elemental metallic targets, and an inductively-coupled RF plasma source to supply active nitrogen species. Growth was monitored in-situ using reflection high-energy electron diffraction (RHEED), and films were characterised using fourier-transform infrared spectroscopy (FTIR) and electron microscopy techniques. Optimised growth conditions led to single-crystal growth of TiN on both substrates, but only polycrystalline AlN was formed directly. Use of a TiN buffer layer on (0001) sapphire led to the successful growth of a single-crystal AlN layer as confirmed by RHEED and high-resolution transmission electron microscopy (HRTEM).

MORPHOLOGICAL STABILITY OF A NANOWIRE DURING GROWTH PROCESS

2001 ◽  
Vol 15 (01) ◽  
pp. 27-31 ◽  
Author(s):  
X. L. CHEN ◽  
J. Y. LI ◽  
Y. C. LAN ◽  
Y. G. CAO
Keyword(s):  
Growth Process ◽  
Axial Direction ◽  
Growth Conditions ◽  
Morphological Stability ◽  
Morphological Instability ◽  
Vapor Liquid Solid ◽  
Fibre Direction ◽  
Vapor Liquid

In this letter, we analyze the morphological stability of a nanowire during the vapor–solid (VS) side growth process at the same time as it grows along its axial direction by the vapor–liquid–solid (VLS) mechanism. The longitudinal perturbations due to the fluctuations of the growth conditions are introduced to describe the morphological variance of a nanowire along its fibre direction. It is shown that the side growth can induce the morphological instability for a nanowire with side perturbations if the perturbation's wavelengths are larger than a nanowire's perimeter.

Thin Coating Deposition by Magnetron Sputtering

2018 ◽  
pp. 403-428 ◽  
Author(s):  
Peter Ifeolu Odetola ◽  
Patricia A. P. Popoola ◽  
Philip Oladijo
Keyword(s):  
Thin Film ◽  
Magnetron Sputtering ◽  
Film Formation ◽  
Semiconductor Industry ◽  
Target Material ◽  
Thin Film Deposition ◽  
Growth Conditions ◽  
High Energy ◽  
Film Deposition ◽  
Atomic Scale

Advances in thin-film deposition expose new frontiers to structures and phases that are inaccessible by conventional chemical means and have led to innovative modification of existing materials' properties. Thin-film deposition by magnetron sputtering is highly dependent on ion bombardments; coupled with sublimation of solid target unto the substrate through momentum transfer. It is summarily base on phase change of target material under high-energy influence; corresponding controlled condensation of sputtered atoms on substrate material during which process parameters and growth conditions dictate the pace of the atomic scale processes for thin-film formation. Magnetron sputtering is a state-of-the-art thin film deposition technique versatile for several unique applications, especially in the semiconductor industry. Magnetron sputtering is very novel in its use to achieve low-pressure condition that maximizes and conserve stream of electrons for effective knocking of inert atoms into ions. This ensures the high-energy acquired is not dissipated in gas-phase collisions.

scholarly journals Simulation of Multicomponent Thin Film Deposition and Growth

1995 ◽  
Vol 389 ◽  
Author(s):  
C. P. Burmester ◽  
L. T. Wille ◽  
R. Gronsky
Keyword(s):  
Thin Film Deposition ◽  
Detailed Examination ◽  
Growth Conditions ◽  
Film Deposition ◽  
Unit Cell ◽  
Deposition Rates ◽  
Cell Height ◽  
Amplitude Data ◽  
Multi Stage ◽  
Growth Modes

ABSTRACTResults from a multicomponent Monte Carlo simulation of the deposition and growth of YBa2Cu3O7 are presented and discussed. In particular, a detailed examination of the growth modes active during different morphological growth conditions is performed. At higher deposition rates, both [001] and [100] epitaxial variants (‘c’ and ‘a’ type growth, respectively) are observed to grow by modes attributed to the classic Volmer-Weber mechanism. At very low deposition rates, the film is observed to grow in a distinct, cyclic, multi-stage process. Small islands of [001] epitaxy nucleate and grow to one unit cell height followed by primarily horizontal growth or “ledge extension” until one unit cell layer has formed. This process then repeats. Simulated RHEED amplitude data from this growth process compares favorably to experimentally obtained data.

Methods in Characterizing the SrTiO3/GaAs Interface

2012 ◽  
Vol 5 (1) ◽  
Author(s):  
T. Cooper ◽  
Q. Qiao ◽  
R.F. Klie
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Gaas Substrate ◽  
Theoretical Calculations ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Transmission Electron ◽  
Significant Interest ◽  
Electron Energy Loss ◽  
Theoretical Results

Characterizing the interface that occurs between a thin-film deposition of SrTiO3 on a GaAs substrate is of significant interest in order to determine the electrical capabilities that may be possible with this type of system. Imaging the interface by using transmission electron microscopy as well as determining important chemical and electrical information by using Electron Energy Loss Spectroscopy (EELS) are critical in determining if the system is actually appropriate for the desired applications. In addition to these experimental calculations, however, it may be useful to determine theoretical calculations in order to confirm and interpret the results. In particular, these may be determined for EELS by using a simulation program called FEFF9, which employs use of full multiple scattering calculations in order to produce these theoretical results.

Growth of Single-Phase 2H-SiC Layers by Vapor–Liquid–Solid Process

2010 ◽  
Vol 645-648 ◽  
pp. 45-48 ◽  
Author(s):  
Mamoru Imade ◽  
Shin Takeuchi ◽  
Masahiro Uemura ◽  
Masashi Yoshimura ◽  
Yasuo Kitaoka ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Carbon Source ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vapor Liquid Solid ◽  
X Ray ◽  
Transmission Electron ◽  
Vls Growth ◽  
Sic Film ◽  
Vapor Liquid

We attempted the vapor–liquid–solid (VLS) growth of SiC film in Si-Li solution using gaseous CH4 as a carbon source at 900 oC. A 100-m-thick liquid-phase epitaxy (LPE) layer was obtained on a 4H-SiC (0001) substrate under CH4 pressure of 0.9 MPa. X-ray diffraction (XRD) and a high-resolution transmission electron microscope (HR-TEM) measurement showed that the LPE layer was single-phase 2H-SiC. We concluded that VLS growth in Si-Li solution using gaseous CH4 as a carbon source is useful for growing single-phase 2H-SiC.

Peculiarities in the Epitaxial Regrowth of Ion-Implanted Si1−xGex Alloy Layers Grown on Compositionally Graded Buffers

1994 ◽  
Vol 373 ◽  
Author(s):  
M. Fyhn ◽  
S. Yu. Shiryaev ◽  
A. Nylandsted Larsen ◽  
J. Lundsgaard Hansen
Keyword(s):  
Composition Range ◽  
Solid Phase ◽  
Linear Interpolation ◽  
Lateral Position ◽  
Growth Conditions ◽  
Alloy Layer ◽  
Compositional Modulation ◽  
Epitaxial Regrowth ◽  
Transmission Electron ◽  
Ion Implanted

AbstractSolid phase epitaxial regrowth of ion-implanted relaxed Si1-xGex layers was studied as a function of alloy composition (0.15< x <0.5) by a combination of Rutherford backscattering/ channeling spectrometry and transmission electron microscopy. The samples were grown by molecular beam epitaxy on compositionally graded buffers at different growth conditions. It was found that the regrowth velocity follows an Arrhenius curve in the investigated composition range and increases with increasing Ge content. The activation energies of the epitaxial regrowth were found to be higher than those expected from a linear interpolation between the values for pure Si and Ge. It is demonstrated that the regrowth velocities in the samples grown at 550 and 750°C and with low-rotational speed of the substrate during growth depend on the lateral position on the wafer and that they can be reduced by a preannealing treatment at high temperatures (σ920°C). We suggest that these effects arise from a compositional modulation in the alloy layer and, therefore, from a symmetrized strain, which can be reduced by a high temperature annealing.

Doping of Al-catalyzed Vapor-liquid-solid Grown Si Nnanowires

2007 ◽  
Vol 1018 ◽  
Author(s):  
Sung Jin Whang ◽  
Sung Joo Lee ◽  
Wei Feng Yang ◽  
Hai Chen Zhu ◽  
Han Lu Gu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Photoelectron Spectroscopy ◽  
Chemical Properties ◽  
Si Nanowires ◽  
Vapor Liquid Solid ◽  
Transmission Electron ◽  
Plasma Doping ◽  
Physical And Chemical ◽  
Vapor Liquid

AbstractWe successfully synthesized high quality single crystal Si nanowires using Al catalyst via vapor-liquid-solid (VLS) mechanism, having diameters ranging from 10 to 200 nm with 10∽20 §­ of length. Characterization of physical and chemical properties of Al-catalyzed Si nanowires using transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) analysis showed that single crystal Si nanowires can be grown with Al-catalyst at 540 ¡C and selective etching of Al existing at the tip of nanowire can provide metal-free Si nanowires that are compatible with conventional Si-based IC process. By using plasma doping method, it was confirmed that the doping level can be controlled and the boron was successfully introduced on Si substrate with 3×1022/cm3 of peak doping concentration.

Vapor-Liquid-Solid Growth of Silicon-Based Nanowires for High Sensitive Sensor

2013 ◽  
Vol 534 ◽  
pp. 257-261 ◽  
Author(s):  
Hayato Sone ◽  
Yasuyuki Suda ◽  
Daiki Kubota ◽  
Sumio Hosaka
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Vapor Liquid Solid ◽  
Transmission Electron ◽  
Current Voltage ◽  
Vls Growth ◽  
Sensitive Sensor ◽  
Current Voltage Characteristics ◽  
Silicon Based ◽  
Vapor Liquid

Silicon-based nanowires (Si-NWs) were fabricated by vapor liquid solid (VLS) growth, and Si-NW device was prototyped using focused ion beam (FIB) processing. The needle shaped thin Si-NWs were formed at a substrate temperature between 1120 and 1313°C. The average and minimum diameters of the NWs were confirmed 60 nm and 44 nm, respectively. As the double-layered structure was observed in the NWs by transmission electron microscope images, it is possible that those are silicon-based NWs with Si core and SiO2shell structure. From current-voltage characteristics, the Si-NW device has a semiconducting property, and the estimated resistivity of the Si-NW is about 3.1 x 104Ωcm.

Silicide Metallization of Aluminum Nitride Substrates for High-Temperature Microelectronics

1995 ◽  
Vol 402 ◽  
Author(s):  
E. Savrun ◽  
M. Sarikaya ◽  
A. Luan ◽  
T. Pearsall
Keyword(s):  
Integrated Circuits ◽  
Aluminum Nitride ◽  
Rf Sputtering ◽  
Thin Film Deposition ◽  
Film Deposition ◽  
Microscopy Imaging ◽  
Transmission Electron ◽  
Metal Silicides ◽  
Heat Treated ◽  
Equilibrium Calculations

AbstractA novel metallization for aluminum nitride substrates to package silicon carbide integrated circuits for use at temperatures up to 600°C was investigated. Chemical equilibrium calculations were used to determine the chemical compatibility of several refractory and transition metal disilicides with AIN. Tungsten disilicide, niobium disilicide, and titanium disilicide were selected for thin film deposition studies. WSi2, NbSi2, and TiSi2 thin films were deposited by RF sputtering on AIN substrates and heat treated at 900°C, 1000°C, and 1200°C in an argon atmosphere. Sheet resistivities were measured and interface stabilities and structures were characterized by scanning and transmission electron microscopy imaging, electron diffraction, and energy dispersive x-ray microanalysis spectroscopy. The results show that metal silicides appear to be promising as metallization for aluminum nitride for use at temperatures above 600°C.

Sign in / Sign up

Export Citation Format

Share Document