Strain Evaluation of GaAs Layers Grown on Ultrahigh-Pressure-Annealed Strain-Free GaAs-On-Si Structures

1997 ◽  
Vol 486 ◽  
Author(s):  
Takehito Jimbo ◽  
Hiroshi Ishiwara
Keyword(s):  
Chemical Vapor ◽  
Xrd Analysis ◽  
Gaas Layer ◽  
Ultrahigh Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Gaas On Si ◽  
Gaas Films ◽  
Regeneration Effect

AbstractIn order to form strain-free GaAs films on Si substrates, GaAs-on-Si structures have been formed by molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD) and subsequently annealed under ultrahigh pressure at 2 GPa. The samples were then reannealed at atmospheric pressure in order to investigate the regeneration effect of strain in the GaAs films. It was found from X-ray diffraction (XRD) analysis and photoluminescence (PL) measurement that in the reannealed samples the strain near the surface of GaAs film was smaller than that near the interface with Si. Finally, additional GaAs layers were grown using MBE on both as-grown and strain-free GaAs-on-Si structures and it was found that the residual strain in the GaAs layer on strain-free GaAs-on-Si structure was smaller than in the as-grown case.

Hot-mesh Chemical Vapor Deposition for 3C-SiC Growth on Si and SiO2

2005 ◽  
Vol 862 ◽  
Author(s):  
Kanji Yasui ◽  
Jyunpei Eto ◽  
Yuzuru Narita ◽  
Masasuke Takata ◽  
Tadashi Akahane
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Rocking Curve ◽  
Mesh Structure ◽  
X Ray ◽  
Si Substrates ◽  
Substrate Temperatures ◽  
Sic Films

AbstractThe crystal growth of SiC films on (100) Si and thermally oxidized Si (SiO2/Si) substrates by hot-mesh chemical vapor deposition (HMCVD) using monomethylsilane as a source gas was investigated. A mesh structure of hot tungsten (W) wire was used as a catalyzer. At substrate temperatures above 750°C and at a mesh temperature of 1600°C, 3C-SiC crystal was epitaxially grown on (100) Si substrates. From the X-ray rocking curve spectra of the (311) peak, SiC was also epitaxially grown in the substrate plane. On the basis of the X-ray diffraction (XRD) measurements, on the other hand, the growth of (100)-oriented 3C-SiC films on SiO2/Si substrates was determined to be achieved at substrate temperatures of 750-800°C, while polycrystalline SiC films, at substrate temperatures above 850°C. From the dependence of growth rate on substrate temperature and W-mesh temperature, the growth mechanism of SiC crystal by HMCVD was discussed.

MO-CVD GaAs Grown by Direct Deposition on Si

1987 ◽  
Vol 91 ◽  
Author(s):  
S. M. Vernon ◽  
S. J. Pearton ◽  
J. M. Gibson ◽  
R. Caruso ◽  
C. R. Abernathy ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Gaas Layer ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Si Substrates ◽  
Transmission Electron ◽  
Activation Data ◽  
Threading Dislocation Density ◽  
Donor Activity

ABSTRACTGaAs layers were grown directly on misoriented (2° off (100)→[011]) Si substrates by Metalorganic Chemical Vapor Deposition. The threading dislocation density at the surface of 4 μm thick layers was typically 108cm−2, as determined by both preferential etching and transmission electron microscopy. Rapid thermal annealing (900°C, 10s) improved the crystalline quality of the GaAs near the heterointerface while allowing no detectable Si diffusion into this layer. Two deep electron traps were observed in the undoped GaAs, but were present at a low concentration (∼ 1013 cm−3 ). The (400) x-ray diffraction peak width from the GaAs was significantly reduced with increasing GaAs layer thickness, indicating improved material quality. This is supported by Si implant activation data, which shows higher net donor activity in thicker layers.

scholarly journals Fabrication of ZnO/CNTs for Application in CO2 Sensor at Room Temperature

Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3087
Author(s):  
Rana Saad ◽  
Ahmed Gamal ◽  
Mohamed Zayed ◽  
Ashour M. Ahmed ◽  
Mohamed Shaban ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Chemical Vapor ◽  
Xrd Analysis ◽  
Chemical Vapor Deposition Method ◽  
Spray Pyrolysis Method ◽  
X Ray Diffraction ◽  
Co2 Gas ◽  
X Ray ◽  
Co2 Sensor ◽  
Higher Sensitivity

Thin films of ZnO and ZnO/carbon nanotubes (CNTs) are prepared and used as CO2 gas sensors. The spray pyrolysis method was used to prepare both ZnO and ZnO/CNTs films, with CNTs first prepared using the chemical vapor deposition method (CVD). The chemical structure and optical analyses for all the prepared nanomaterials were performed using X-ray diffraction (XRD), Fourier transformer infrared spectroscopy (FTIR), and UV/Vis spectrophotometer devices, respectively. According to the XRD analysis, the crystal sizes of ZnO and ZnO/CNTs were approximately 50.4 and 65.2 nm, respectively. CNTs have average inner and outer diameters of about 3 and 13 nm respectively, according to the transmitted electron microscope (TEM), and a wall thickness of about 5 nm. The detection of CO2 is accomplished by passing varying rates of the gas from 30 to 150 sccm over the prepared thin-film electrodes. At 150 sccm, the sensitivities of ZnO and ZnO/CNTs sensors are 6.8% and 22.4%, respectively. The ZnO/CNTs sensor has a very stable sensitivity to CO2 gas for 21 days. Moreover, this sensor has a high selectivity to CO2 in comparison with other gases, in which the ZnO/CNTs sensor has a higher sensitivity to CO2 compared to H2 and C2H2.

scholarly journals Ag-induced a New Raman Mode in ZnO Microrods

2019 ◽  
Vol 25 (3) ◽  
pp. 227-230
Author(s):  
Jing WANG ◽  
Lina WANG ◽  
Meina WANG ◽  
Dan ZHOU ◽  
Yan MEI ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Raman Mode ◽  
X Ray Diffraction ◽  
Characteristic Mode ◽  
Raman Analysis ◽  
X Ray ◽  
Ag Doping ◽  
Si Substrates ◽  
Hexagonal Shape ◽  
Vapor Deposition Technique

The chemical vapor deposition technique was used to prepare the Ag doped ZnO microrods, which were located on Si substrates at two different positions.  The scanning electron microscopy revealed that the samples have a clear hexagonal shape. X-ray diffraction provided information about the preferential orientation along the c-axis. The Raman analysis revealed that a new Raman mode appears at 492 cm-1 due to Ag doping. As this mode has not been reported early, it could be used as a characteristic mode of Ag doping in Raman spectrum. The red shift of the E2 (high) mode proves the existence of tensile stress in the samples. DOI: http://dx.doi.org/10.5755/j01.ms.25.3.19130

Influence of Ammonia on the Fabrication of Aligned Carbon Nanotubes Using Thermal CVD

2011 ◽  
Vol 467-469 ◽  
pp. 312-315
Author(s):  
Gang Li ◽  
Wen Ming Cheng
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor ◽  
X Ray Diffraction ◽  
Vertical Alignment ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Aligned Carbon Nanotubes ◽  
20 Nm

Ultra-thin (20 nm) nickel catalyst films were deposited by sputtering on SiO2/Si substrates. At the pretreatments, ammonia (NH3) was conducted for different time in a thermal chemical vapor deposition (CVD) system. Pretreated samples were characterized using atomic force microscopy (AFM). After the pretreatment, acetylene was introduced into the chamber for 10 min, samples were characterized using scanning electron micrograph (SEM) and X-ray diffraction (XRD). It was concluded that NH3 pretreatment was very crucial to control the surface morphology of catalytic metals and thus to achieve the vertical alignment of carbon nanotubes (CNTs). With higher density of the Ni particles, better alignment of the CNTs can be obtained due to steric hindrance effect between neighboring CNTs.

Residual Stress in GaAs Layer Grown on 4°-Off (100)Si by MBE

1987 ◽  
Vol 91 ◽  
Author(s):  
T. Yao ◽  
Y. Okada ◽  
H. Kawanami ◽  
S. Matsui ◽  
A. Imagawa ◽  
...  
Keyword(s):  
Residual Stress ◽  
Tensile Stress ◽  
Gaas Layer ◽  
Residual Tensile Stress ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Misfit Stress ◽  
Si Substrates ◽  
Gaas Films ◽  
Semiconductor Laser Diodes

ABSTRACTResidual stress in molecular beam epitaxially (MBE) grown GaAs films on 4°-off (100)Si substrates is investigated with X-ray diffraction technique. It is experimentally confirmed that the GaAs lattice suffers tetragonal deformation with the c-axis being [100]. The GaAs lattice tilts by approximately 0.2° towards the tilted direction of the substrate. It is found that two-dimensional compressive stress dominates in GaAs films thinner than 0.3 μm in thickness, while two-dimensional tensile stress dominates in thicker films. The variation of the stress is understood in terms of a combination of misfit stress and thermal stress. The residual tensile stress is larger than 1 × 109 dyn/cm2 in the films thicker than I pm. The effect of the stress on the reliability of semiconductor laser diodes is discussed.

Crystalline Orientation of PbTiO3 Nanorods Grown by MOCVD Using ZnO Nanorods as a Template

2011 ◽  
Vol 1292 ◽  
Author(s):  
Hironori Fujisawa ◽  
Masaru Shimizu ◽  
Ryohei Kuri ◽  
Seiji Nakashima ◽  
Yasutoshi Kotaka ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Zno Nanorods ◽  
Chemical Vapor ◽  
Piezoresponse Force Microscopy ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Crystalline Orientation ◽  
X Ray ◽  
Force Microscopy

ABSTRACTPbTiO3-covered ZnO nanorods were grown on Al2O3$\left({11\bar 20} \right)$ by metalorganic chemical vapor deposition (MOCVD), and their crystalline orientation was investigated by x-ray diffraction (XRD). Structural analysis by scanning electron microscopy and XRD revealed that the hexagonal ZnO nanorods had $\left\{ {10\bar 10} \right\}$-side facets. XRD analysis of PbTiO3 thin films on ZnO$\left({10\bar 10} \right)$/Al2O3$\left({10\bar 10} \right)$revealed that PbTiO3 was epitaxially grown on ZnO$\left({10\bar 10} \right)$, showing 6 variants of crystallites with the c-axis tilted either 27o or 69o from the surface normal to the ZnO$\left({10\bar 10} \right)$ plane. Effective piezoelectric coefficients calculated for the 27o and 69o-crystallites using piezoresponse force microscopy confirm that deformation of nanorods and nanotubes contributed to the large electrically-induced strain along the radial direction.

Integration of GaAs on Ge/Si towers by MOVPE

2013 ◽  
Vol 1538 ◽  
pp. 283-289
Author(s):  
A. G. Taboada ◽  
T. Kreiliger ◽  
C. V. Falub ◽  
M. Richter ◽  
F. Isa ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Morphological Evolution ◽  
Chemical Vapor ◽  
Lattice Parameter ◽  
Low Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Si Substrates ◽  
Organic Vapor ◽  
Metal Organic

ABSTRACTWe report on the maskless integration of micron-sized GaAs crystals on patterned Si substrates by metal organic vapor phase epitaxy. In order to adapt the mismatch between the lattice parameter and thermal expansion coefficient of GaAs and Si, 2 μm tall Ge crystals were first grown as virtual substrate by low energy plasma enhanced chemical vapor deposition. We investigate the morphological evolution of the GaAs structures grown on top of the Ge crystals at the transition towards full pyramids with energetically stable {111} facets. A substantial release of strain is shown in GaAs crystals with a height of 2 μm and lateral sizes up to 15×15 μm2 by both X-ray diffraction and photoluminescence.

MOCVD Growth of III-V Compounds on Si Using Strained Superlattices

1986 ◽  
Vol 67 ◽  
Author(s):  
Shiro Sakai ◽  
Tetsuo Soga ◽  
Masanari Takeyasu ◽  
Masayoshi Umeno
Keyword(s):  
Electronic Properties ◽  
Intermediate Layer ◽  
Lattice Mismatch ◽  
Gaas Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Double Heterostructure ◽  
Si Substrates ◽  
Mocvd Growth ◽  
Structural And Electronic Properties

ABSTRACTGaAs and GaAsP with the entire compositional range are grow on Si using an intermediate layer of GaAsP strained superlattices to relax the lattice mismatch. The orientation of the overgrown GaAs layer is found to be determined by the direction of the off-angle of the Si (100) surface. The grown layers are characterized by photoluminescence, x-ray diffraction, electro reflectance and DLTS. GaAs/GaAlAs double heterostructure lasers and GaAsP visible LED's are fabricated on Si substrates. The structural and electronic properties of the grown layers and the device performances are reported in this paper.

Low Temperature Chemical Vapor Deposition of 3C-SiC on Si Substrates

2005 ◽  
Vol 483-485 ◽  
pp. 201-204 ◽  
Author(s):  
Christian Förster ◽  
Volker Cimalla ◽  
Oliver Ambacher ◽  
Jörg Pezoldt
Keyword(s):  
Gas Phase ◽  
Vapor Deposition ◽  
Growth Process ◽  
Chemical Vapor ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force

In the present work an UHVCVD method was developed which allows the epitaxial growth of 3C-SiC on Si substrates at temperatures below 1000°C. The developed method enable the growth of low stress or nearly stress free single crystalline 3C-SiC layers on Si. The influence of hydrogen on the growth process are be discussed. The structural properties of the 3C-SiC(100) layers were studied with reflection high-energy diffraction, atomic force microscopy, X-ray diffraction and the layer thickness were measured by reflectometry as well as visible ellipsometry. The tensile strain reduction at optimized growth temperature, Si/C ratio in the gas phase and deposition rate are demonstrated by the observation of freestanding SiC cantilevers.

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