Mbe Growth and Characterization of GaAs thin Films on SiGe Buffer Layers

1988 ◽  
Vol 116 ◽  
Author(s):  
S.M. Prokes ◽  
W.F. Tseng ◽  
B.R. Wilkins ◽  
H. Dietrich ◽  
A. Christou
Keyword(s):  
Electron Microscopy ◽  
Growth Process ◽  
Molecular Beam ◽  
Buffer Layers ◽  
Defect Production ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Step Growth ◽  
Scanning Electron

AbstractEpitaxial SiGe buffers have been formed by the implantation of 74Ge+ ions into Si(100)4° to <011> substrates. The implants were made at 150keV to a dose of 1×1017 /cm2 . The epitaxial layers were characterized by Rutherford backscattering, Raman spectroscopy, and electroreflectance and were found to be 300Å thick having on average a composition of Si0 . 35 Ge0.65. GaAs layers were then grown on these substrates by molecular beam epitaxy, using the standard two-step growth process. The results from Auger, Scanning Electron Microscopy, and Cross-sectional TEM indicate a lower defect production and propagation in these samples, compared to those grown directly on Si.

Characterization of Thin Polymer Blend Films using ESEM – No Charging, No Staining.

2001 ◽  
Vol 707 ◽  
Author(s):  
Ian C. Bache ◽  
Catherine M. Ramsdale ◽  
D. Steve Thomas ◽  
Ana-Claudia Arias ◽  
J. Devin MacKenzie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Cross Sectional ◽  
Blend Films ◽  
Thin Polymer ◽  
Device Applications ◽  
Scanning Electron

ABSTRACTCharacterising the morphology of thin films for use in device applications requires the ability to study both the structure within the plane of the film, and also through its thickness. Environmental scanning electron microscopy has proved to be a fruitful technique for the study of such films both because contrast can be seen within the film without the need for staining (as is conventionally done for electron microscopy), and because cross-sectional images can be obtained without charging artefacts. The application of ESEM to a particular blend of relevance to photovoltaics is described.

Migration-Enhanced Molecular Beam Epitaxial Growth and Characterization of GaAs on Si Substrates

1988 ◽  
Vol 144 ◽  
Author(s):  
J.H. Kim ◽  
S. Sakai ◽  
J.K. Liu ◽  
G. Raohakrishnan ◽  
S.S. Chang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Cross Sectional ◽  
Light Emitting ◽  
Si Substrates ◽  
Molecular Beam Epitaxial

ABSTRACTWe first report on migration-enhanced molecular beam epitaxial (MEMBE) growth and characterization of the GaAs layers on Si substrates (GaAs/Si). Excellent surface morphology GaAs layers were successfully grown on (100) Sisubstrates misoriented 4 toward [110] direction. The MEMBE growth method isdescribed and material properties are compared with those of normal two-step MBE-grown or in-situ annealed layers. Micrographs of cross-sectional view transmission electron microscopy (TEM) and scanning surface electron microscopy (SEM) of MEMBE-grown GaAs/Si showed dislocation densities of 107 cm-2 over ten times lower than those of two-step MBE-grown or in-situ annealedlayers. AlGaAs/GaAs double heterostructure lasers and light-emitting diodeshave been successfully grown on MEMBE GaAs/Si by both metal organic chemical vapor deposition and liquid phase epitaxy. MOCVD-grown lasers showed peak output power as high as 184 mW/facet, pulsed threshold currents as low as150 mA at 300 K, and differential quantum efficiencies of up to 30 %. The LPE-grown light-emitting diodes showed output powers of 1.5 mW and external quantum efficiencies of 3.3 mW/A per facet.

MBE GROWTH OF GaAs NANOWHISKERS STIMULATED BY THE ADATOM DIFFUSION

2007 ◽  
Vol 06 (03n04) ◽  
pp. 225-231 ◽  
Author(s):  
V. G. DUBROVSKII ◽  
I. P. SOSHNIKOV ◽  
A. A. TONKIKH ◽  
V. M. USTINOV ◽  
G. E. CIRLIN ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Molecular Beam ◽  
Growth Conditions ◽  
Growth Mechanisms ◽  
Vapor Liquid Solid ◽  
Mbe Growth ◽  
Drop Radius ◽  
Adatom Diffusion ◽  
Vapor Liquid Solid Mechanism ◽  
Scanning Electron

The growth mechanisms of GaAs nanowhiskers (NWs) during molecular beam epitaxy (MBE) are studied theoretically and experimentally. A kinetic model of the diffusion-induced NW growth is presented that allows one to predict the dependence of NW length on the drop radius and on the technologically controlled MBE growth conditions. The results of scanning electron microscopy studies of GaAs NWs grown at different conditions on the GaAs (111) B surface activated by Au are presented and analyzed. It is shown that the length of NWs increases with decreasing the drop radius and with decreasing the deposition rate of GaAs , while its temperature dependence has a certain maximum. The aspect ratio of MBE-grown GaAs NWs is higher than 100. The maximum length of NWs is several times larger than the effective thickness of the deposited GaAs . The obtained results demonstrate that the NW growth is controlled by the adatom diffusion toward their tip rather than by the adsorption-induced vapor–liquid–solid mechanism. The growth conditions' influence on the NW morphology may be used for the controlled fabrication of NWs by MBE for different applications.

Three Dimensional Characterization of Interfaces in Semiconductors by Scanning Electron Microscopy

1986 ◽  
Vol 69 ◽  
Author(s):  
David C. Joy ◽  
D. M. Maher ◽  
R C Farrow
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Preparation Time ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Alternative Approach ◽  
Imaging Mode ◽  
Structural Characterizations ◽  
Scanning Electron

AbstractIn many semiconductor materials problems, structural characterizations must be achieved in both the lateral and vertical dimensions. Although a combination of cross-sectional and planar transmission electron microscopy can provide this information, the sample preparation time is demanding and only relatively small volumes of material are examined. We describe here an alternative approach in which the charge collection (‘CCM’) imaging mode of the scanning electron microscope (SEM) is used. It is shown that, by varying the incident electron beam energy, electricallly active defects at different positions beneath the entrance surface of the material can be imaged and their depth estimated.

Structures of Nb/Al2O3 Interfaces Produced by Different Experimental Routes

1990 ◽  
Vol 183 ◽  
Author(s):  
J. Mayer ◽  
W. Mader ◽  
D. Knauss ◽  
F. Ernst ◽  
M. Rühle
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Molecular Beam ◽  
Al Alloy ◽  
Misfit Dislocations ◽  
Orientation Relationships ◽  
Cross Sectional ◽  
Mbe Growth ◽  
Sapphire Substrates ◽  
Transmission Electron

AbstractNb/Al2O3 interfaces were produced by (i) diffusion bonding of single crystalline Nb and Al2O3 at 1973 K, (ii) internal oxidation of a Nb-3at.% Al alloy at 1773 K, and (iii) molecular beam epitaxy (MBE) growth of 500 nm thick Nb overlayers on sapphire substrates at 1123 K. Cross-sectional specimens were prepared and studied by conventional (CTEM) and high resolution transmission electron microscopy (HREM). The orientation relationships between Nb and Al2O3 were identified by diffraction studies. HREM investigations revealed the structures of the different interfaces including the presence of misfit dislocations at or near the interface. The results for the different interfaces are compared.

Growth of CuInS2 Films on Crystalline Substrates

1996 ◽  
Vol 426 ◽  
Author(s):  
R. Hunger ◽  
R. Scheer ◽  
M. Alt ◽  
H. J. Lewerenz
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Molecular Beam ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Growth Morphology ◽  
Cross Sectional ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Electron

AbstractCuInS2 films were grown by molecular beam epitaxy (MBE) on hydrogen terminated Si(111) substrates with 4° miscut. X-ray diffraction (XRD) texture analysis reveals that CuInS2 was grown heteroepitaxially with the epitaxial relationships CuInS2(112) II Si(111) and [111] II [111]. Moreover, a substantial amount of rotational twins is observed. The crystalline order is maintained across the interface as observed by cross-sectional transmission electron microscopy (XTEM). XRD and scanning electron microscopy (SEM) investigations show that nonstoichiometric preparation greatly influences the growth morphology and leads to the formation of secondary phases.

Characterization of AlGaAs/InGaAs/GaAs Heteroepitaxial Layers by Transmission Electron Microscopy and Energy Dispersive Spectroscopy

1992 ◽  
Vol 281 ◽  
Author(s):  
R. S. Rai ◽  
J. M. Tartaglia ◽  
W. E. Quinn ◽  
D. C. Martel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Energy Dispersive Spectroscopy ◽  
Molecular Beam ◽  
Energy Dispersive ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Periodic Striation ◽  
Heteroepitaxial Layers

ABSTRACTAlGaAs/InGaAs/GaAs heteroepitaxial layers grown by molecular beam epitaxy were studied by cross-sectional transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The presence of waviness/roughness, fine periodic striation contrast due to Al composition oscillations, and defects were observed by TEM in selected samples. EDS on the TEM was of limited utility in determining the composition of thin epitaxial layers and in comparing the composition near and away from a defect. Arguments are presented to rationalize these results.

Mbe Growth and Characterization of (GaAs)l−x(Si2)x and (GaAs)1−x(Si2)x/GaAs Superlattices on GaAs Substrates

1995 ◽  
Vol 379 ◽  
Author(s):  
H.P. Lee ◽  
F.J. Szalkowski ◽  
X. Zeng ◽  
J. Wolfenstine ◽  
J. W. Ager
Keyword(s):  
Molecular Beam ◽  
Stacking Faults ◽  
Cross Sectional ◽  
Mbe Growth ◽  
X Ray ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Evaporation Source ◽  
Scattering Measurement

ABSTRACTLateral compositional graded (GaAs)1-x(Si2)x alloys were deposited on GaAs substrates in a III-V molecular beam epitaxy (MBE) chamber equipped with a electron-beam Si evaporation source. Single crystal GaAs-Si alloys were formed when the deposition temperature was 600°C or higher. The alloys were characterized by Energy Dispersive X-ray Spectroscopy (EDS), Raman scattering measurement and cross-sectional Transmission Electron Microscopy (XTEM). Dislocation-free (GaAs)1-x(Si2)x films of up to x = 0.07 were deposited. For alloys with x between 0.15 < < 0.25, the morphology deteriorates and a high density of stacking faults and micro-twins were observed.

Characterization of Thin Polymer Blend Films using ESEM – No Charging, No Staining.

2001 ◽  
Vol 710 ◽  
Author(s):  
Ian C. Bache ◽  
Catherine M. Ramsdale ◽  
D. Steve Thomas ◽  
Ana-Claudia Arias ◽  
J. Devin MacKenzie ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Cross Sectional ◽  
Blend Films ◽  
Thin Polymer ◽  
Device Applications ◽  
Scanning Electron

ABSTRACTCharacterising the morphology of thin films for use in device applications requires the ability to study both the structure within the plane of the film, and also through its thickness. Environmental scanning electron microscopy has proved to be a fruitful technique for the study of such films both because contrast can be seen within the film without the need for staining (as is conventionally done for electron microscopy), and because cross-sectional images can be obtained without charging artefacts. The application of ESEM to a particular blend of relevance to photovoltaics is described.

Sign in / Sign up

Export Citation Format

Share Document