Electronic structure of short-period ZnSe/ZnTe superlattices grown by MOVPE at 300ºC

1993 ◽  
Vol 308 ◽  
Author(s):  
N. Briot ◽  
T. Cloitre ◽  
O. Briot ◽  
P. Boring ◽  
B.E. Ponga ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Lattice Mismatch ◽  
Stokes Shift ◽  
Vapour Phase ◽  
Potential Candidate ◽  
High Quality ◽  
Vapour Phase Epitaxy ◽  
Light Emitting Devices ◽  
Short Period ◽  
Movpe Growth

ABSTRACTThe ZnSe-ZnTe combination is a potential candidate for the realisation of visible light-emitting devices. The lattice mismatch between bulk ZnSe and bulk ZnTe is important (∼ 8%). Therefore, their hetero-structures are strained and high quality superlattices will only be grown if having small periods. This prescription can be fulfilled in the case of metal organic vapour phase epitaxy (MOVPE) growth by combining triethylamine dimethyl zinc adduct with di-isopropyl telluride as precursors for the growth of the ZnTe layers. The growth of high quality ZnTe can then be performed at a temperature of 300ºC , close to the best MOVPE-growth temperature for ZnSe (280ºC). Lowering the growth temperature of ZnTe to this value, we could thus obtain sharp interfaces. This work reports on ZnSe-ZnTe superlattices grown on ZnSe and ZnTe buffers deposited on GaAs substrates. We demonstrate that the stokes-shift between the reflectance and photoluminescence features ( ∼ 40 meV ) measured when the thickness of ZnSe layers does not exceed 20 Å, drastically increases for layer thicknesses beyond this critical value. This, we interpret in terms of the onset of plastic relaxation which favours tellurium diffusion in the ZnSe slices. Then photoluminescence spectra broaden ( contributions of trapped-excitons dominate), and observation of free excitons in reflectance become impossible. We have studied in detail the optical properties of the superlattices and compared our findings with the predictions of a multiband envelope function calculation. We show that both zone centre excitons as well as excitons associated with the miniband dispersions (saddle-point excitons) are observed in these superlattices.

A Tem study of GaN Grown by ELO on (0001) 6H-SiC

1999 ◽  
Vol 595 ◽  
Author(s):  
P. Ruterana ◽  
B. Beaumont ◽  
P. Gibart ◽  
Y. Melnik
Keyword(s):  
Basal Plane ◽  
Lattice Mismatch ◽  
Early Stage ◽  
Vapour Phase ◽  
Epitaxial Layers ◽  
Prismatic Plane ◽  
Vapour Phase Epitaxy ◽  
Hexagonal Shape ◽  
To Come

AbstractThe misfit between GaN and 6H-SiC is 3.5% instead of 16% with sapphire, the epitaxial layers have similar densities of defects on both substrates. Moreover, the lattice mismatch between AlN and 6H-SiC is only 1%. Therefore, epitaxial layer overgrowth (ELO) of GaN on AlN/6H-SiC could be a route to further improve the quality of epitaxial layers. AlN has been grown by Halide Vapour Phase Epitaxy (HVPE) on (0001) 6H-SiC, thereafter a dielectric SiO2 mask was deposited and circular openings were made by standard photolithography and reactive ion etching. We have examined GaN layers at an early stage of coalescence in order to identify which dislocations bend and try to understand why. The analysed islands have always the same hexagonal shape, limited by {0110} facets. The a type dislocations are found to fold many times from basal to the prismatic plane, whereas when a+c dislocations bend to the basal plane, they were not seen to come back to a prismatic one.

scholarly journals Characterisation of III?V Multilayers Grown by Low-pressure Metal Organic Vapour-phase Epitaxy

1993 ◽  
Vol 46 (3) ◽  
pp. 435
Author(s):  
C Jagadish ◽  
A Clark ◽  
G Li ◽  
CA Larson ◽  
N Hauser ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Growth Temperature ◽  
Deep Level ◽  
Growth Parameters ◽  
Low Pressure ◽  
Vapour Phase ◽  
Growth Conditions ◽  
Vapour Phase Epitaxy ◽  
Metal Organic ◽  
Organic Vapour

Undoped and doped layers of gallium arsenide and aluminium gallium arsenide have been grown on gallium arsenide by low-pressure metal organic vapour-phase epitaxy (MOVPE). Delta doping and growth on silicon substrates have also been attempted. Of particular interest in the present study has been the influence of growth parameters, such as growth temperature, group III mole fraction and dopant flow, on the electrical and physical properties of gallium arsenide layers. An increase in growth temperature leads to increased doping efficiency in the case of silicon, whereas the opposite is true in the case of zinc. Deep level transient spectroscopy (DTLS) studies on undoped GaAs layers showed two levels, the expected EL2 level and a carbon-related level. The determination of optimum growth conditions has allowed good quality GaAs and AlGaAs epitaxial layers to be produced for a range of applications.`

High quality ELO-GaN layers on GaN/Al2O3 patterned substrates by halide vapour phase epitaxy

1999 ◽  
Vol 59 (1-3) ◽  
pp. 112-116 ◽  
Author(s):  
G. Nataf ◽  
B. Beaumont ◽  
A. Bouillé ◽  
P. Vennéguès ◽  
S. Haffouz ◽  
...  
Keyword(s):  
Vapour Phase ◽  
Patterned Substrates ◽  
High Quality ◽  
Vapour Phase Epitaxy

Ge Assisted 3C-SiC Nucleation and Growth by Vapour Phase Epitaxy on On-Axis 4H-SiC Substrate

2014 ◽  
Vol 806 ◽  
pp. 27-31
Author(s):  
Kassem Alassaad ◽  
Véronique Soulière ◽  
Marelina Vivona ◽  
Filippo Giannazzo ◽  
Fabrizio Roccaforte ◽  
...  
Keyword(s):  
Growth Temperature ◽  
Vapour Phase ◽  
Nucleation And Growth ◽  
Single Domain ◽  
Vapour Phase Epitaxy ◽  
Surface Pretreatment

The aim of this work is to study the effect of Ge introduction during the nucleation step on the SiC growth on 4H-SiC on-axis substrate. After 10 minutes surface pretreatment at 1500°C under C3H8or GeH4, the grown 3C layer at the same temperature can switch from highly twinned (C3H8) to almost twin-free single domain (GeH4). However, for too low and too high GeH4fluxes, the layers display a mixture of polytype. Keeping the best pretreatment but varying the growth temperature degrades the morphology and changes the polytype of the layer. Preliminary electrical results using C-AFM on the 3C-SiC layer are also presented.

Lateral overgrowth of high quality GaN layers on GaN/Al2O3 patterned substrates by halide vapour-phase epitaxy

1998 ◽  
Vol 192 (1-2) ◽  
pp. 73-78 ◽  
Author(s):  
G Nataf ◽  
B Beaumont ◽  
A Bouillé ◽  
S Haffouz ◽  
M Vaille ◽  
...  
Keyword(s):  
Vapour Phase ◽  
Patterned Substrates ◽  
High Quality ◽  
Vapour Phase Epitaxy ◽  
Lateral Overgrowth

Metal Organic Vapour Phase Epitaxy (MOVPE) Growth of GaN(n)/SiC(p) Heterostructures

1999 ◽  
Vol 176 (1) ◽  
pp. 109-112
Author(s):  
H. Lahrèche ◽  
M. Vaille ◽  
B. Beaumont ◽  
M. Laügt ◽  
P. Vennéguès ◽  
...  
Keyword(s):  
Vapour Phase ◽  
Vapour Phase Epitaxy ◽  
Movpe Growth ◽  
Metal Organic ◽  
Organic Vapour

scholarly journals Advanced AlGaAs/GaAs Heterostructures Grown by MOVPE

Crystals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 305 ◽  
Author(s):  
Maxim A. Ladugin ◽  
Irina V. Yarotskaya ◽  
Timur A. Bagaev ◽  
Konstantin Yu. Telegin ◽  
Andrey Yu. Andreev ◽  
...  
Keyword(s):  
Quantum Cascade Lasers ◽  
Vapour Phase ◽  
Vapour Phase Epitaxy ◽  
Quantum Cascade ◽  
Ultrathin Layers ◽  
Metalorganic Vapour Phase Epitaxy ◽  
Short Period ◽  
Output Characteristics ◽  
Cascade Lasers ◽  
High Repeatability

AlGaAs/GaAs heterostructures are the base of many semiconductor devices. The fabrication of new types of devices demands heterostructures with special features, such as large total thickness (~20 μm), ultrathin layers (~1 nm), high repeatability (up to 1000 periods) and uniformity, for which a conventional approach of growing such heterostructures is insufficient and the development of new growth procedures is needed. This article summarizes our work on the metalorganic vapour-phase epitaxy (MOVPE) growth of AlGaAs/GaAs heterostructures for modern infrared devices. The growth approaches presented allow for the improved output characteristics of different emitting devices such as multi active region lasers, epitaxially integrated via highly doped tunnel junctions (emission wavelength λ ~ 1 μm), quantum cascade lasers (λ ~10 μm) and THz laser (λ ~100 μm), based on short-period superlattice with 500–2000 layers.

scholarly journals Strain relaxation in GaN layers grown on porous GaN sublayers

1999 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Mynbaeva ◽  
A. Titkov ◽  
A. Kryzhanovski ◽  
I. Kotousova ◽  
A.S. Zubrilov ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Strain Relaxation ◽  
Vapour Phase ◽  
Crystalline Quality ◽  
Epitaxial Layers ◽  
High Quality ◽  
High Crystalline Quality ◽  
Vapour Phase Epitaxy ◽  
X Ray ◽  
Good Surface

We have studied epitaxial GaN layers grown by hydride vapour phase epitaxy (HVPE) on porous GaN sublayers formed on SiC substrates. It was shown that these layers can be grown with good surface morphology and high crystalline quality. X-ray, Raman and photoluminescent (PL) measurements showed that the stress in the layers grown on porous GaN was reduced to 0.1-0.2 GPa, while the stress in the layers grown directly on 6H-SiC substrates remains at its usual level of about 1 GPa. Thus, we have shown that growth on porous GaN sublayer is a promising method for fabrication of high quality epitaxial layers of GaN with low strain values.

Ion Scattering Studies of Defects In Gan Thin Films on C-Oriented Sapphire

1998 ◽  
Vol 512 ◽  
Author(s):  
B. Holländer ◽  
S. Mantl ◽  
M. Mayer ◽  
C. Kirchner ◽  
A. Pelzmann ◽  
...  
Keyword(s):  
Lattice Mismatch ◽  
Vapour Phase ◽  
Structural Defects ◽  
Ion Scattering ◽  
Vapour Phase Epitaxy ◽  
Screw Dislocations ◽  
Ion Channeling ◽  
Thermal Expansion Coefficients ◽  
Organic Vapour ◽  
Edge Dislocations

ABSTRACTEpitaxial GaN films grown by metal organic vapour phase epitaxy (MOVPE) or gas source molecular beam epitaxy (GSMBE) have opened up new applications in short wavelength photonic devices as well as high-power and high-temperature devices. The large lattice mismatch of 14% between GaN and sapphire, which is frequently used as the substrate, and the different thermal expansion coefficients generally lead to high densities of structural defects. We investigate the defect structure of MOVPE- and GSMBE-grown GaN layers on sapphire by Rutherford backscattering and ion channeling measurements. Channeling along the c-axis revealed χmin-values as low as 1.2% even in samples with dislocation densities in the order of 109 cm−2. Channeling measurements along different crystal planes were performed in order to improve the sensitivity to dechanneling by crystalline defects. Angular yield scans around the c-axis indicate clearly the hexagonal symmetry of the GaN lattice. Dechanneling results were combined with transmission electron microscopy investigations (TEM). The results suggest that the dechanneling-cross-section of edge dislocations is about 4 times larger than the dechannelingcross-section of screw dislocations. screw dislocations.

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