Drastic Reduction of Threading Dislocation Density of AlGaN on SiC Wafer by Using Highly-Si-Incorporated AlGaN Superlattice

2000 ◽  
Vol 639 ◽  
Author(s):  
Hideki Hirayama ◽  
Makoto Ainoya ◽  
Atsuhiro Kinoshita ◽  
Akira Hirata ◽  
Yoshinobu Aoyagi
Keyword(s):  
Dislocation Density ◽  
Threading Dislocation ◽  
Drastic Reduction ◽  
Organic Vapor ◽  
Threading Dislocation Density ◽  
Metal Organic ◽  
Total Growth ◽  
Sic Wafer ◽  
Algan Buffer

ABSTRACTA new in-situ technique to reduce threading dislocation density (TDD) within sub- micron growth is demonstrated by using metal-organic vapor-phase epitaxy (MOVPE). We achieved drastic reduction of TDD of AlGaN buffer on SiC substrate by inserting highly-Si- incorporated AlGaN/undoped AlGaN superlattice (SL). TDD of AlGaN was decreased from 2×1010 to 7×107 cm−2 by inserting the SL with the total growth thickness of 0.8νm. Si incorporation in AlGaN SL was estimated to be 1.2×1020 cm−3. This technique is exactly in- situ process without complicated fabrication processes, and the surface is kept flat throughout the total growth. This method is especially useful on SiC wafer in order to prevent cracks with thin growth layer. We confirmed the similar effects for GaN and AlGaN buffer on sapphire substrates.

Reduction of Threading Dislocation Density in AlGaN by Indium Incorporation

2003 ◽  
Vol 798 ◽  
Author(s):  
H. Kang ◽  
Z. C. Feng ◽  
I. Ferguson ◽  
S. P. Guo ◽  
M. Pophristic
Keyword(s):  
Dislocation Density ◽  
Structural Properties ◽  
Coherence Length ◽  
Chemical Vapor ◽  
Columnar Structure ◽  
Organic Chemical ◽  
Threading Dislocation ◽  
Reciprocal Space Mapping ◽  
Threading Dislocation Density ◽  
Metal Organic

ABSTRACTThe addition of indium, even to small concentrations, to AlGaN has resulted in improved optical and doping properties for these materials. This paper is the first report of improved structural properties for indium containing AlGaN layers. A systematic series of the AlGaN layers with nominal concentration of 20% aluminum were grown by metal-organic chemical vapor deposition with traces amounts of indium incorporated into the layers (up to 0.15% indium). X-ray diffraction analysis of the layers was completed using Williamson Hall plots and reciprocal space mapping to investigate any change in the columnar structure of the initial AlGaN layers. It was found that the threading dislocation densities and lateral coherence length showed a systematic variation with indium incorporation. The threading dislocation density is lowered as indium composition increased with a corresponding increase in lateral coherence length. This indicates that even the incorporation of trace amounts of indium improves the structural properties of these epilayers.

Drastic Reduction of Dislocation Density in Semipolar (1122) GaN Stripe Crystal on Si Substrate by Dual Selective Metal–Organic Vapor Phase Epitaxy

2011 ◽  
Vol 50 (1S1) ◽  
pp. 01AD04 ◽  
Author(s):  
Tasuku Murase ◽  
Tomoyuki Tanikawa ◽  
Yoshio Honda ◽  
Masahito Yamaguchi ◽  
Hiroshi Amano ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Si Substrate ◽  
Drastic Reduction ◽  
Organic Vapor ◽  
Metal Organic

Reduction of Threading Dislocation Density in InN Film Grown with in situ Surface Modification by Radio-frequency Plasma-excited Molecular Beam Epitaxy

MRS Advances ◽  
2018 ◽  
Vol 3 (18) ◽  
pp. 931-936
Author(s):  
F. B. Abas ◽  
R. Fujita ◽  
S. Mouri ◽  
T. Araki ◽  
Y. Nanishi
Keyword(s):  
Surface Modification ◽  
Electrical Properties ◽  
Dislocation Density ◽  
Hall Effect Measurement ◽  
Threading Dislocation ◽  
X Ray ◽  
Transmission Electron ◽  
Threading Dislocation Density ◽  
Order Of Magnitude

ABSTRACTThe objective of this study was to investigate the relationship between the thickness of N radical irradiated InN template with crystallographic quality and electrical properties of InN film grown with the previously proposed method, in situ surface modification by radical beam irradiation. In this study, three InN samples were grown with this method on different thickness of irradiated templates. The crystallographic quality of InN films was analyzed by X-ray diffraction and the electrical properties were studied by Hall effect measurement. InN grown on 100 nm thick irradiated template shows lower full-width at half-maximum of X-ray rocking curves and lower carrier concentration compared to InN grown on 200 nm and 450 nm thick irradiated templates. Transmission electron microscopy revealed that threading dislocation density in the InN film decreased by an order of magnitude to ∼4.6×109cm-2. These results suggest that this method is possible for reduction of threading dislocation density in InN and the thickness of irradiated template should be minimized for higher crystallographic quality and electrical properties of the entire InN film.

In Situ Study of Isothermal Strain Relaxation in Si-Ge Heteroepitaxial Films Using Substrate Curvature Measurements

1991 ◽  
Vol 239 ◽  
Author(s):  
Véronique T. Gillard ◽  
David B. Noble ◽  
William D. Nix
Keyword(s):  
Dislocation Density ◽  
Laser Scanning ◽  
Isothermal Annealing ◽  
Strain Relaxation ◽  
Threading Dislocation ◽  
Relaxation Measurements ◽  
Threading Dislocation Density ◽  
Device Applications ◽  
Curvature Measurements

ABSTRACTUnderstanding die kinetics and mechanisms of strain relaxation in Si-Ge heteroepitaxial films is pertinent to several device applications. In this paper we present a method for determining the evolution of the mobile dislocation density with time during the course of strain relaxation taking place in an isothermal annealing experiment.Wafer curvature measurements using a laser scanning technique are used to determine the elastic strain after growth in films of variable thickness and to follow the strain relaxation during isothermal annealing experiments. By coupling the strain relaxation measurements with previous TEM measurements of dislocation velocities in this system, the mobile threading dislocation density and its evolution with time are determined.

Efficient 350 nm LEDs on low edge threading dislocation density AlGaN buffer layers

2011 ◽  
Author(s):  
Richard Gutt ◽  
Thorsten Passow ◽  
Wilfried Pletschen ◽  
Michael Kunzer ◽  
Lutz Kirste ◽  
...  
Keyword(s):  
Dislocation Density ◽  
Buffer Layers ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Algan Buffer

High-Irradiance Degradation Studies of Metamorphic 1eV GaInAs Solar Cells

2012 ◽  
Vol 1432 ◽  
Author(s):  
Ryan M. France ◽  
Myles A. Steiner
Keyword(s):  
Solar Cells ◽  
Active Region ◽  
Dislocation Density ◽  
Dark Current ◽  
Degradation Mechanism ◽  
Control Cell ◽  
High Irradiance ◽  
Threading Dislocation ◽  
Threading Dislocation Density ◽  
Degradation Studies

ABSTRACTInitial tests are performed regarding the degradation of lattice-mismatched GaInAs solar cells. 1eV metamorphic GaInAs solar cells with 1-2×106 cm-2 threading dislocation density in the active region are irradiated with an 808 nm laser for 2 weeks time under a variety of temperature and illumination conditions. All devices show a small degradation in Voc that is logarithmic with time. The absolute loss in performance after 2 weeks illuminated at 1300 suns equivalent and 125°C is 7 mV Voc and 0.2% efficiency, showing these devices to be relatively stable. The dark current increases with time and is analyzed with a two-diode model. A GaAs control cell degrades at the same rate, suggesting that the observed degradation mechanism is not related to the additional dislocations in the GaInAs devices.

Sign in / Sign up

Export Citation Format

Share Document