Investigation of epitaxial lateral overgrowth by x‐ray topography

1992 ◽  
Vol 72 (2) ◽  
pp. 405-409 ◽  
Author(s):  
R. Köhler ◽  
B. Jenichen ◽  
E. Bauser ◽  
R. Bergmann
Keyword(s):  
Epitaxial Lateral Overgrowth ◽  
X Ray ◽  
Lateral Overgrowth

Four-inch high quality crack-free AlN layer grown on a high-temperature annealed AlN template by MOCVD

2021 ◽  
Vol 42 (12) ◽  
pp. 122804
Author(s):  
Shangfeng Liu ◽  
Ye Yuan ◽  
Shanshan Sheng ◽  
Tao Wang ◽  
Jin Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Flat Surface ◽  
Epitaxial Lateral Overgrowth ◽  
High Temperature Annealing ◽  
High Quality ◽  
High Crystalline Quality ◽  
X Ray ◽  
Lateral Overgrowth

Abstract In this work, based on physical vapor deposition and high-temperature annealing (HTA), the 4-inch crack-free high-quality AlN template is initialized. Benefiting from the crystal recrystallization during the HTA process, the FWHMs of X-ray rocking curves for (002) and (102) planes are encouragingly decreased to 62 and 282 arcsec, respectively. On such an AlN template, an ultra-thin AlN with a thickness of ~700 nm grown by MOCVD shows good quality, thus avoiding the epitaxial lateral overgrowth (ELOG) process in which 3–4 μm AlN is essential to obtain the flat surface and high crystalline quality. The 4-inch scaled wafer provides an avenue to match UVC-LED with the fabrication process of traditional GaN-based blue LED, therefore significantly improving yields and decreasing cost.

Structural evaluation of GaN/sapphire grown by epitaxial lateral overgrowth by X-ray microdiffraction

2006 ◽  
Vol 243 (7) ◽  
pp. 1545-1550 ◽  
Author(s):  
M. Drakopoulos ◽  
M. Laügt ◽  
T. Riemann ◽  
B. Beaumont ◽  
P. Gibart
Keyword(s):  
Epitaxial Lateral Overgrowth ◽  
X Ray ◽  
Structural Evaluation ◽  
Lateral Overgrowth

Epitaxial Lateral Overgrowth of Gallium Arsenide Studied by Synchrotron Topography

1999 ◽  
Vol 570 ◽  
Author(s):  
R. Rantamäki ◽  
T. Tuomi ◽  
Z. R. Zytkiewicz ◽  
D. Dobosz ◽  
P. J. Mcnally ◽  
...  
Keyword(s):  
Gallium Arsenide ◽  
Surface Profile ◽  
Epitaxial Lateral Overgrowth ◽  
Simulation Data ◽  
X Ray ◽  
Lateral Overgrowth ◽  
Lattice Planes ◽  
Section Topographs ◽  
Transmission And Reflection ◽  
Good Agreement

ABSTRACTSynchrotron x-ray topographs of GaAs epitaxial lateral overgrowth (ELO) samples are made both in transmission and reflection geometries. The topographs show that the bending of the ELO layers is visible in most geometries. A simulation of the topographic images is implemented taking into account only the orientational contrast. Simulated back reflection section topographs are in good agreement with the experimental ones. The shape of the lattice planes in an ELO layer is calculated using the simulation data and compared to the measured surface profile of the same ELO stripe.

Mask-Induced Strain in Gaas Layers Grown by Liquid Phase Epitaxial Lateral Overgrowth

1999 ◽  
Vol 570 ◽  
Author(s):  
Z.R. Zytkiewicz ◽  
J. Domagala ◽  
D. Dobosz
Keyword(s):  
Liquid Phase ◽  
Epitaxial Lateral Overgrowth ◽  
X Ray Diffraction ◽  
Liquid Phase Epitaxial ◽  
X Ray ◽  
Vertical Strain ◽  
Lateral Overgrowth ◽  
Gaas Substrates ◽  
Show Evidence ◽  
Vertical Growth Rate

ABSTRACTX-ray diffraction has been used to study the mask-induced strain in GaAs layers grown by the liquid phase epitaxial lateral overgrowth (ELO) on (100) GaAs substrates. SiO2 mask has been investigated to produce seeding areas for the ELO growth. It has been found that SiO2 attracts the ELO layers, which leads to their pronounced bending towards the oxide film and to the appearance of vertical strain in laterally grown parts of ELO. When SiO2 is removed by selective etching this strain disappears. We show evidence that the bending of ELO layers is reduced when the density of substrate dislocations is increased. This is explained as being due to enhancement of the initial vertical growth rate by dislocations supplying steps on the upper surface of ELO.

Epitaxial Lateral Overgrowth of GaN on Sapphire - An Examination of Epitaxy Quality Using Synchrotron X-Ray Topography

2001 ◽  
Vol 185 (2) ◽  
pp. 373-382 ◽  
Author(s):  
P.J. McNally ◽  
T. Tuomi ◽  
D. Lowney ◽  
K. Jacobs ◽  
A.N. Danilewsky ◽  
...  
Keyword(s):  
Epitaxial Lateral Overgrowth ◽  
X Ray ◽  
Lateral Overgrowth

scholarly journals Void Shapes Controlled by Using Interruption-Free Epitaxial Lateral Overgrowth of GaN Films on Patterned SiO2AlN/Sapphire Template

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yu-An Chen ◽  
Cheng-Huang Kuo ◽  
Li-Chuan Chang ◽  
Ji-Pu Wu
Keyword(s):  
Electron Microscopy ◽  
Epitaxial Lateral Overgrowth ◽  
Threading Dislocation ◽  
X Ray Diffraction ◽  
Air Voids ◽  
X Ray ◽  
Lateral Overgrowth ◽  
Transmission Electron ◽  
Gan Film ◽  
Scanning Electron

GaN epitaxial layers with embedded air voids grown on patterned SiO2AlN/sapphire templates were proposed. Using interruption-free epitaxial lateral overgrowth technology, we realized uninterrupted growth and controlled the shape of embedded air voids. These layers showed improved crystal quality using X-ray diffraction and measurement of etching pits density. Compared with conventional undoped-GaN film, the full width at half-maximum of the GaN (0 0 2) and (1 0 2) peaks decreased from 485 arcsec to 376 arcsec and from 600 arcsec to 322 arcsec, respectively. Transmission electron microscopy results showed that the coalesced GaN growth led to bending threading dislocation. We also proposed a growth model based on results of scanning electron microscopy.

Detailed Characterisations of GaAs Films on Si Obtained by Conformal Growth.

1992 ◽  
Vol 280 ◽  
Author(s):  
B. Gerard ◽  
D. Pribat ◽  
R. Bisaro ◽  
E. Costard ◽  
J. Nagle ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Dislocation Density ◽  
The Self ◽  
Epitaxial Lateral Overgrowth ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lateral Overgrowth ◽  
State Of Stress ◽  
Low Dislocation Density ◽  
Gaas Films

ABSTRACTConformal growth is a confined epitaxial lateral overgrowth technique capable of yielding low dislocation density GaAs films on Si. This technique makes extensive use of selective epitaxy and crystal growth is confined by a dielectric cap as well as by the self-passivated Si surface itself.In this paper, we have performed a detailed characterisation of the state of stress of the GaAs films in various configurations (after conformal growth and removal of the seed regions, and after the regrowth of an MBE layer) by photoluminescence measurements at 5K and X-ray diffraction experiments. Although the as-grown conformal films are found in the same state of stress than reference MOCVD GaAs epilayers on Si, we report a significant decrease of this stress after MBE regrowth on conformal films.

Synchrotron X-ray Topography Studies of Epitaxial Lateral Overgrowth of GaN on Sapphire

1999 ◽  
Vol 572 ◽  
Author(s):  
Patrick J. Mcnally ◽  
T. Tuomi ◽  
R. Rantamaki ◽  
K. Jacobs ◽  
L. Considine ◽  
...  
Keyword(s):  
Quantum Well ◽  
Sapphire Substrate ◽  
Large Scale ◽  
Epitaxial Lateral Overgrowth ◽  
Large Area ◽  
X Ray ◽  
Lateral Overgrowth ◽  
Transmission Modes ◽  
Multi Quantum Well

ABSTRACTSynchrotron white beam x-ray topography techniques, in section and large-area transmission modes, have been applied to the evaluation of ELOG GaN on A12O3. Using the openings in 100 nm thick SiO2 windows, a new GaN growth took place, which resulted in typical overgrowth thicknesses of 6.8 μm. Measurements on the recorded Laue patterns indicate that the misorientation of GaN with respect to the sapphire substrate (excluding a 30° rotation between them) varies considerably along various crystalline directions, reaching a maximum of a ∼0.66° rotation of the (0001) plane about the [01•1] axis. This is ∼3% smaller than the misorientation measured in the non-ELOG reference, which reached a maximum of 0.68°. This misorientation varies measurably as the stripe or window dimensions are changed. The quality of the ELOG epilayers is improved when compared to the non- ELOG samples, though some local deviations from lattice coherence were observed. Long range and large-scale (order of 100 μm long) strain structures were observed in all multi quantum well epilayers.

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