A refined scheme for the reduction of threading dislocation densities in InxGa1−xAs/GaAs epitaxial layers

1996 ◽  
Vol 80 (12) ◽  
pp. 6706-6710 ◽  
Author(s):  
G. MacPherson ◽  
P. J. Goodhew
Keyword(s):  
Epitaxial Layers ◽  
Threading Dislocation ◽  
Dislocation Densities

X-Ray Diffraction Analysis of GaN and AlGaN

2002 ◽  
Vol 743 ◽  
Author(s):  
H. Kang ◽  
N. Spencer ◽  
D. Nicol ◽  
Z. C. Feng ◽  
I. Ferguson ◽  
...  
Keyword(s):  
Tilt Angle ◽  
Coherence Length ◽  
Twist Angle ◽  
Columnar Structure ◽  
Epitaxial Layers ◽  
Threading Dislocation ◽  
Reciprocal Space Mapping ◽  
Nucleation Layer ◽  
X Ray ◽  
Dislocation Densities

ABSTRACTIn this paper, threading dislocation densities in GaN and AlGaN epitaxial layers have been evaluated using two different X-ray analysis techniques; a Williamson Hall (WH) plot and reciprocal space mapping (RSM). GaN and AlGaN have crystalline growth composed of columnar structures that can be estimated by coherence length and angular misorientation measured by X-ray. A WH plot can provide information about coherence length and tilt angle from a linear fit to the linewidth of the triple axis rocking curve (000l) symmetric reflections. RSM is typically used to obtain this data, but it is more involved in technique. The two dominant components of threading dislocation densities (screw and edge types) in the GaN and AlGaN epitaxial layers were found to be similar by both techniques. The treading dislocation density correlates to the size of columnar structure as determined by coherence length, tilt angle, and twist angle. The effect of Al composition in AlGaN alloys on these dislocation densities was investigated and found to depend on strongly on the type of nucleation layer, GaN or AlN.

Defect-Engineered Graded GexSi1-x Buffers on Si (001) with Extreme Low Threading Dislocation Density

1995 ◽  
Vol 378 ◽  
Author(s):  
G. Kissinger ◽  
T. Morgenstern ◽  
G. Morgenstern ◽  
H. B. Erzgräber ◽  
H. Richter
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Dislocation Density ◽  
Threading Dislocation ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Threading Dislocation Density

AbstractStepwise equilibrated graded GexSii-x (x≤0.2) buffers with threading dislocation densities between 102 and 103 cm−2 on the whole area of 4 inch silicon wafers were grown and studied by transmission electron microscopy, defect etching, atomic force microscopy and photoluminescence spectroscopy.

Totally relaxed GexSi1−xlayers with low threading dislocation densities grown on Si substrates

1991 ◽  
Vol 59 (7) ◽  
pp. 811-813 ◽  
Author(s):  
E. A. Fitzgerald ◽  
Y.‐H. Xie ◽  
M. L. Green ◽  
D. Brasen ◽  
A. R. Kortan ◽  
...  
Keyword(s):  
Threading Dislocation ◽  
Si Substrates ◽  
Dislocation Densities

High Quality AlN Layer Grown on Patterned Sapphire Substrates by Hydride Vapor-Phase Epitaxy: A Route for Cost Efficient AlN Templates for Deep Ultraviolet Light Devices

2021 ◽  
Vol 21 (9) ◽  
pp. 4881-4885
Author(s):  
Seung-Jae Lee ◽  
Seong-Ran Jeon ◽  
Young Ho Song ◽  
Young-Jun Choi ◽  
Hae-Gon Oh ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Vapor Phase Epitaxy ◽  
Hydride Vapor Phase Epitaxy ◽  
Threading Dislocation ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Order Of Magnitude ◽  
Cost Efficient ◽  
Patterned Sapphire Substrates

We report the characteristics of AlN epilayers grown directly on cylindrical-patterned sapphire substrates (CPSS) by hydride vapor-phase epitaxy (HVPE). To evaluate the effect of CPSS, we analyzed the threading dislocation densities (TDDs) of AlN films grown simultaneously on CPSS and flat sapphire substrate (FSS) by transmission electron microscopy (TEM). The corresponding TDD is measured to be 5.69 x 108 cm−2 for the AlN sample grown on the CPSS that is almost an order of magnitude lower than the value of 3.43 × 109 cm−2 on the FSS. The CPSS contributes to reduce the TDs originated from the AlN/sapphire interface via bending the TDs by lateral growth during the coalescence process. In addition, the reduction of direct interface area between AlN and sapphire by CPSS reduce the generation of TDs.

Evaluation of threading dislocation densities in In- and N-face InN

2010 ◽  
Vol 107 (5) ◽  
pp. 053517 ◽  
Author(s):  
C. S. Gallinat ◽  
G. Koblmüller ◽  
Feng Wu ◽  
J. S. Speck
Keyword(s):  
Threading Dislocation ◽  
Dislocation Densities

Relaxed Ge0.9Si0.1 alloy layers with low threading dislocation densities grown on low-temperature Si buffers

1998 ◽  
Vol 72 (24) ◽  
pp. 3160-3162 ◽  
Author(s):  
C. S. Peng ◽  
Z. Y. Zhao ◽  
H. Chen ◽  
J. H. Li ◽  
Y. K. Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Threading Dislocation ◽  
Dislocation Densities

High Voltage AlGaN/GaN Heterojunction Transistors

2004 ◽  
Vol 14 (01) ◽  
pp. 225-243 ◽  
Author(s):  
L. S. McCarthy ◽  
N-Q. Zhang ◽  
H. Xing ◽  
B. Moran ◽  
S. DenBaars ◽  
...  
Keyword(s):  
Drain Current ◽  
Gate Insulator ◽  
Threading Dislocation ◽  
High Electron ◽  
Resistive Load ◽  
Power Switching ◽  
Field Plate ◽  
Switching Power ◽  
Dislocation Densities ◽  
Extrinsic Base

The use of AlGaN / GaN HEMTs and HBTs for switching power supplies is explored. With its high electron velocities and breakdown fields, GaN has great potential for power switching. The field-plate HEMT increased breakdown voltages by 20% to 570V by reducing the peak field at the drain-side edge of the gate. The use of a gate insulator is also investigated, using both JVD SiO 2 and e-beam evaporated SiO 2 to reduce gate leakage, increasing breakdown voltages to 1050V and 1300V respectively. The power device figure of merit (FOM) for these devices: [Formula: see text], is the highest reported for switching devices. To reduce trapping effects, reactively sputtered SiN x, is used as a passivant, resulting in a switching time of less than 30 ns for devices blocking over 110V with a drain current of 1.4A under resistive load conditions. Dynamic load results are also presented. The development of HBTs for switching applications included the development of an etched emitter HBT with a selectively regrown extrinsic base. This was later improved upon with the selectively regrown emitter devices with current gains as high as 15. To improve breakdown in these devices, thick GaN layers were grown, reducing threading dislocation densities in the active layers. A further improvement included the use of a bevelled shallow etch and a lateral collector design to maximize device breakdown.

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