Composition and Strain Analysis of Semiconductor Heterostructures Using Thickness Fringes on Tem Images

1994 ◽  
Vol 332 ◽  
Author(s):  
H. Kakibayashi ◽  
R. Tsuneta ◽  
F. Nagata
Keyword(s):  
Multiple Quantum Well ◽  
Strain Analysis ◽  
Dynamical Theory ◽  
Multiple Quantum ◽  
Strained Layers ◽  
Quantum Well Structures ◽  
Depth Profiles ◽  
Transmission Electron ◽  
The Difference ◽  
Induced Defects

ABSTRACTComposition and strain depth profiles in heterostructures such as AlGaAs/GaAs, InGaAs/InP and SiGe/Si have been analyzed with a high resolution of 0.5 nm by using the thickness fringes in a transmission electron microscope image. This diagnostic method is found to successfully evaluate the compositional disordering caused by annealing multiple quantum well structures with abrupt interfaces, and determine the difference in strain distribution in the strained-layers with various lattice mismatches. Both the composition and strain depth-profiles are analyzed quantitatively by the image simulation based on the dynamical theory of electron diffraction. This method is also useful for sensitively detecting ion-implantation-induced defects.

High-Resolution X-ray Diffraction Analysis of p-Type Strained InGaAs/AlGaAs Multiple Quantum Well Structures

1999 ◽  
Vol 607 ◽  
Author(s):  
W. Shi ◽  
D. H. Zhang ◽  
T. Osotchan ◽  
P.H. Zhang ◽  
S. F. Yoon ◽  
...  
Keyword(s):  
Quantum Well ◽  
Doping Concentration ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Doping Density ◽  
Quantum Well Structures ◽  
As Doping ◽  
Transmission Electron ◽  
P Type

AbstractBe-doped InGaAs/AIGaAs multiple quantum well (MQW) structures, grown by solid-source molecular beam epitaxy with different doping concentration in the wells, were investigated by xray diffraction and transmission electron microscopy (TEM). Some features have been observed. (1) The MQW mean mismatch increases from 1.176 × 10−3 to 1.195 × 10−3 and 1.29 × 10−3 for the structures with doping concentration of 1 × 1017 cm−3, 1 × 1018cm−3and 2 × 1019 cm−3 in the wells, respectively. (2) The period of the MQW also increases with doping density. (3) The intensity of the first order satellite in the rocking curves decreases as the Be concentration is increased, indicating that indium diffusion in the heavily doped wells is likely more significant than that in the lightly doped ones. (4) The full width at half maximum of the zero-order satellite peak becomes widened as doping concentration increases, indicating that high Be-doping in the well likely deteriorates the interfaces of the multiple quantum well stacks. In addition, TEM measurement is conducted and clear pictures on well and barrier layers of the structures are observed. The information obtained is of great value for the design of p-doped quantum well infrared photodetectors.

Approaches Toward Chemically Prepared Multiple Quantum Well Structures

1998 ◽  
Vol 545 ◽  
Author(s):  
S. B. Cronin ◽  
T. Koga ◽  
X. Sun ◽  
Z. Ding ◽  
S.-C. Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Well ◽  
Quantum Wells ◽  
Self Assembly ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
X Ray Diffraction ◽  
Quantum Well Structures ◽  
Transmission Electron ◽  
2D System

AbstractAn enhanced thermoelectric figure of merit, ZT, has been predicted for Bi2Te3 in the form of 2-dimensional quantum wells. A new approach to making multiple quantum well (MQW) structures for thermoelectric applications utilizing a chemical intercalation technique is proposed and investigated. It is proposed that by starting from Li intercalated Bi2Te3 and Bi2Se3, the layers of these materials can be separated by chemical means. The layers of Bi2Te3 or Bi2 Se3 can then be restacked, by self-assembly, forming a non-periodic array of quantum wells. These chemically prepared MQWs are characterized by X-ray diffraction, SEM (scanning electron microscopy) and TEM (transmission electron microscopy) at various stages in the sample preparation to assess the degree to which the actual samples match the proposal. Experimental measurements of the Seebeck coefficient (S) and the electrical conductivity (σ) were performed over a range of temperatures for the initial bulk materials. It is found that some of the steps in the proposed fabrication have been achieved but still much improvement is needed before any practical thermoelectric 2D-system can be provided.

Band Offsets of InAsxP1−X/InP Strained Layer Quantum Wells Grown by Lp-Movpe Using TBAs

1994 ◽  
Vol 358 ◽  
Author(s):  
M. Beaudoin ◽  
R.A. Masut ◽  
L. Isnard ◽  
P. Desjardins ◽  
A. Bensaada ◽  
...  
Keyword(s):  
Quantum Wells ◽  
Absorption Spectra ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Energy Position ◽  
Band Offsets ◽  
Quantum Well Structures ◽  
Strained Layer ◽  
Transmission Electron ◽  
Metal Organic

ABSTRACTLow temperature optical absorption spectra are presented for a series of InAsxP1-x/InP strained layer multiple quantum well structures (0 < x = 0.35) grown by low pressure metal organic vapor phase epitaxy (LP-MOVPE) using trimethylindium (TMIn), tertiarybutylarsine (TBAs) and phosphine as precursors. The well widths and compositions in these structures are determined from high resolution x-ray diffraction and transmission electron microscopy. The absorption spectra are then analyzed by fitting the excitonic peak energy position with transition energies determined from a solution to the Schrödinger equation. We used the envelope function formalism with the Kane bands as the basis wavefunctions and included corrections for non parabolicity. From these fits and elasticity theory, both the bandgap of unstrained InAsxP1-x and the band offsets of these heterostructures are deduced self-consistently. The conduction band offsets are found between 72% and 75% of the total strained bandgap differences.

RESONANT TUNNELING STUDIES OF VARIABLY SPACED MULTIPLE QUANTUM WELL STRUCTURES IN THE AlGaAs SYSTEM

1987 ◽  
Vol 48 (C5) ◽  
pp. C5-457-C5-461
Author(s):  
C. J. SUMMERS ◽  
K. F. BRENNAN ◽  
A. TORABI ◽  
H. M. HARRIS ◽  
J. COMAS
Keyword(s):  
Quantum Well ◽  
Resonant Tunneling ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Quantum Well Structures

Electroabsorption by Stark effect on room‐temperature excitons in GaAs/GaAlAs multiple quantum well structures

1983 ◽  
Vol 42 (10) ◽  
pp. 864-866 ◽  
Author(s):  
D. S. Chemla ◽  
T. C. Damen ◽  
D. A. B. Miller ◽  
A. C. Gossard ◽  
W. Wiegmann
Keyword(s):  
Quantum Well ◽  
Room Temperature ◽  
Stark Effect ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Quantum Well Structures

High photoluminescence quantum efficiency InGaN multiple quantum well structures emitting at 380nm

2007 ◽  
Vol 101 (3) ◽  
pp. 033516 ◽  
Author(s):  
D. M. Graham ◽  
P. Dawson ◽  
G. R. Chabrol ◽  
N. P. Hylton ◽  
D. Zhu ◽  
...  
Keyword(s):  
Quantum Well ◽  
Quantum Efficiency ◽  
Multiple Quantum Well ◽  
Multiple Quantum ◽  
Quantum Well Structures

Visible-wavelength laser action of ZnCdO∕(Zn,Mg)O multiple quantum well structures

2007 ◽  
Vol 91 (23) ◽  
pp. 231103 ◽  
Author(s):  
S. Sadofev ◽  
S. Kalusniak ◽  
J. Puls ◽  
P. Schäfer ◽  
S. Blumstengel ◽  
...  
Keyword(s):  
Quantum Well ◽  
Multiple Quantum Well ◽  
Laser Action ◽  
Multiple Quantum ◽  
Quantum Well Structures ◽  
Visible Wavelength
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