scholarly journals Structural Properties of Lattice-Matched InGaPN on GaAs (001)

2018 ◽  
Vol 63 (3) ◽  
pp. 276 ◽  
Author(s):  
P. Sritonwong ◽  
S. Sanorpim ◽  
K. Onabe
Keyword(s):  
Structural Properties ◽  
Annealing Time ◽  
Lattice Mismatch ◽  
Matching Condition ◽  
N Content ◽  
Force Microscopy ◽  
Optimum Growth Temperature ◽  
Atomic Force ◽  
Gaas Buffer Layer ◽  
Lattice Matched

Structural properties of lattice-matched InGaPN on GaAs (001) have comprehensively investigated by high resolution X-ray diffraction (HRXRD), Raman spectroscopy, and atomic force microscopy (AFM). The InGaPN layers were grown by metal organics vapor phase epitaxy (MOVPE). To obtain the lattice-matched InGaPN on GaAs, flow rates of trimethylindium (TMIn), trimethylgallium (TMGa) were kept, respectively, at 14.7 and 8.6 /umol/min. On the other hand, the N content optimized by varying the flow rate of dimethyhydrazine (DMHy, N precursor) was controlled at 300 /umol/min. With a combination of HRXRD and Raman scattering measurements, the In and N contents are estimated to be 55.8 and 0.9 at%, respectively. The lattice-mismatch lower than 0.47%, which corresponds to the lattice-matching condition, was confirmed for all the layers. The rapid thermal annealing (RTA) process was performed to improvement the crystalline quality of InGaPN layers. The annealing temperature was fixed at 650∘C, which is an optimum growth temperature of a GaAs buffer layer. The annealing time was varied in a range of 30 to 180 s to verify a composition uniformity. With increasing the annealing time up to 120 s, the In and N contents were slightly increased. The AFM-root mean square (RMS) roughness of the InGaPN surface was observed to be reduced. For higher annealing times, the N content was dramatically reduced, whereas the In content was still remained. Moreover, the RMS roughness was observed to be increased. RTA at 650∘C for 120 s demonstrated a significant improvement of structural properties of the lattice-matched InGaPN layers on GaAs (001).

THE EFFECT OF In0.1Ga0.9As UNDERLYING LAYER ON THE STRUCTURAL PROPERTIES OF SELF-ASSEMBLED In0.5Ga0.5As QUANTUM DOTS

NANO ◽  
2011 ◽  
Vol 06 (02) ◽  
pp. 153-157 ◽  
Author(s):  
DIDIK ARYANTO ◽  
ZULKAFLI OTHAMAN ◽  
ABD. KHAMIM ISMAIL
Keyword(s):  
Quantum Dots ◽  
Structural Properties ◽  
Strain Relaxation ◽  
Single Layer ◽  
Force Microscopy ◽  
Atomic Force ◽  
Tem Characterization ◽  
Transmission Electron ◽  
Gaas Buffer Layer ◽  
Induced Defects

The effect of a thin In0.1Ga0.9As underlying layer on the structural properties of single layer In0.5Ga0.5As quantum dots (QDs) was investigated using atomic force microscopy (AFM), transmission electron microscopy (TEM) and high-resolution X-ray diffraction (HR-XRD) characterization. The size of dots formed on the surface is uniform but the density increases with the addition of In0.1Ga0.9As underlying between In0.5Ga0.5As QDs and GaAs buffer layer. This is consistent with the TEM characterization. The existence of thin underlying layer has caused the dots to have different crystal orientation as shown in TEM characterization. From the HR-XRD characterization, broad peak of In0.1Ga0.9As underlying layer and QDs has been observed. The wider width of the layer peak than the expected one has been attributed to the strain-relaxation-induced defects. The growth of a thin In0.1Ga0.9As underlying layer in the In0.5Ga0.5As/GaAs structures strongly affects the structural properties, which was also believed to influence the optical properties of QDs.

ANNEALING TIME EFFECT ON NANOSTRUCTURED n-ZnO/p-Si HETEROJUNCTION PHOTODETECTOR PERFORMANCE

2015 ◽  
Vol 22 (02) ◽  
pp. 1550027 ◽  
Author(s):  
NADIR. F. HABUBI ◽  
RAID. A. ISMAIL ◽  
WALID K. HAMOUDI ◽  
HASSAM. R. ABID
Keyword(s):  
Annealing Time ◽  
Silicon Substrates ◽  
X Ray Diffraction ◽  
Zno Nps ◽  
Force Microscopy ◽  
Atomic Force ◽  
Junction Type ◽  
P Type ◽  
Quartz Substrates ◽  
Two Peaks

In this work, n- ZnO /p- Si heterojunction photodetectors were prepared by drop casting of ZnO nanoparticles (NPs) on single crystal p-type silicon substrates, followed by (15–60) min; step-annealing at 600∘C. Structural, electrical, and optical properties of the ZnO NPs films deposited on quartz substrates were studied as a function of annealing time. X-ray diffraction studies showed a polycrystalline, hexagonal wurtizte nanostructured ZnO with preferential orientation along the (100) plane. Atomic force microscopy measurements showed an average ZnO grain size within the range of 75.9 nm–99.9 nm with a corresponding root mean square (RMS) surface roughness between 0.51 nm–2.16 nm. Dark and under illumination current–voltage (I–V) characteristics of the n- ZnO /p- Si heterojunction photodetectors showed an improving rectification ratio and a decreasing saturation current at longer annealing time with an ideality factor of 3 obtained at 60 min annealing time. Capacitance–voltage (C–V) characteristics of heterojunctions were investigated in order to estimate the built-in-voltage and junction type. The photodetectors, fabricated at optimum annealing time, exhibited good linearity characteristics. Maximum sensitivity was obtained when ZnO / Si heterojunctions were annealed at 60 min. Two peaks of response, located at 650 nm and 850 nm, were observed with sensitivities of 0.12–0.19 A/W and 0.18–0.39 A/W, respectively. Detectivity of the photodetectors as function of annealing time was estimated.

Anisotropic Behaviour of Surface Roughening in Lattice Mismatched Heteroepitaxial Thin Films

1996 ◽  
Vol 436 ◽  
Author(s):  
Cengiz S. Ozkan ◽  
William D. Nix ◽  
Huajian Gao
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Lattice Mismatch ◽  
Surface Roughening ◽  
Silicon Substrates ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Annealing Experiments

AbstractHeteroepitaxial Si1-xGex. thin films deposited on silicon substrates exhibit surface roughening via surface diffusion under the effect of a compressive stress which is caused by a lattice mismatch. In these films, surface roughening can take place in the form of ridges which can be aligned along <100> or <110> directions, depending on the film thickness. In this paper, we investigate this anisotropic dependence of surface roughening and present an analysis of it. We have studied the surface roughening behaviour of 18% Ge and 22% Ge thin films subjected to controlled annealing experiments. Transmission electron microscopy and atomic force microscopy have been used to study the morphology and microstructure of the surface ridges and the dislocations that form during annealing.

Preparation and Time Resolved Photoluminescence of Nanoscale InP Islands in In0.48Ga0.52P

1995 ◽  
Vol 379 ◽  
Author(s):  
K. Eberl ◽  
A. Kurtenbach ◽  
K. HÄusler ◽  
F. Noll ◽  
W.W. RÜhle
Keyword(s):  
Lattice Mismatch ◽  
Excitation Power ◽  
Buffer Layers ◽  
Time Resolved ◽  
Force Microscopy ◽  
Self Assembling ◽  
Atomic Force ◽  
Transmission Electron ◽  
Decay Times ◽  
Time Resolved Photoluminescence

ABSTRACTNanoscale InP islands are formed during InP/In0 48Ga0.52P heteroepitaxy due to the lattice mismatch of about 3.7%. The samples are prepared by solid source molecular beam epitaxy on (001) GaAs substrate. Atomic force microscopy measurements show that the size of the islands is typically 15 to 50 nm in diameter and about 5 to 10 nm high depending on the nominally deposited InP layer thickness, which is between 1 and 7.5 monolayers. Transmission electron micrographs show the coherent incorporation into the In0.48Ga0.52P matrix for InP islands with 2.5 monolayers. Resonantly excited time-resolved photoluminescence (PL) measurements of the self assembling InP dots are performed for optical characterisation. The decay times are typically 400 ps. The dependence on excitation power and temperature indicates the quantum dot nature of the InP islands. Finally a pronounced alignment of the InP islands is obtained on strained In0.61Ga0.39P buffer layers.

Growth of heteroepitaxial GaSb thin films on Si(100) substrates

2004 ◽  
Vol 19 (8) ◽  
pp. 2315-2321 ◽  
Author(s):  
Thang Nguyen ◽  
Walter Varhue ◽  
Edward Adams ◽  
Mark Lavoie ◽  
Stephen Mongeon
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Lattice Mismatch ◽  
Stacking Faults ◽  
Heteroepitaxial Growth ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Radio Frequency Sputtering ◽  
Atomic Force ◽  
Transmission Electron

The heteroepitaxial growth of GaSb thin films on Si(100) and GaAs(100) substrates is presented. The growth technique involves the use of atomic Ga and Sb species, which are provided by thermal effusion and radio frequency sputtering, respectively. The crystalline quality of the heteroepitaxial GaSb film on the Si substrate is high despite the larger lattice mismatch. Epitaxial quality is determined by high-resolution x-ray diffraction and Rutherford backscatter spectrometry channeling. Atomic-force microscopy is used to monitor the evolution of surface morphology with increasing film thickness. Transmission electron microscopy shows the formation of stacking faults at the Si/GaSb interface and their eventual annihilation with increasing GaSb film thickness. Annihilation of stacking faults occurs when two next-neighbor mounds meet during the overgrowth of a common adjacent mound.

EFFECT OF N CONTENT ON THE THERMAL STABILITY OF Ta–Si–N THIN FILM BARRIER LAYER

2010 ◽  
Vol 24 (30) ◽  
pp. 5867-5875
Author(s):  
JICHENG ZHOU ◽  
ZHENG LIU ◽  
XUQIANG ZHENG ◽  
YOUZHEN LI ◽  
DITIAN LUO
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Sheet Resistance ◽  
Diffusion Barrier ◽  
Diffraction Method ◽  
N Content ◽  
Force Microscopy ◽  
Atomic Force ◽  
Nano Crystalline ◽  
P Type

Ta–Si–N thin films and Cu/Ta–Si–N thin films were deposited on p-type Si (111) substrates by magnetron reactive sputtering. Then the films were characterized by four-point probe sheet resistance measurement, atomic force microscopy, X-ray diffraction method and scanning electron microscope, respectively. The experimental results show that the sheet resistance of Ta–Si–N thin film increases with N content. And the surface roughness of the thin film first decreases and then increases with N content. By increasing the N content, the diffusion barrier property of Ta–Si–N thin film can be improved; however, this improvement is not evident when N content beyond 56%. The as-deposited Ta–Si thin film is nano-crystalline. When doped with N, the as-deposited thin film becomes amorphous. The crystallization of Ta–Si–N thin film occurs again at high temperature. Cu atoms diffuse through grain boundaries of Ta–Si–N thin film into Si , and this leads to failure of the diffusion barrier.

CRYSTAL STRUCTURE AND GAS SENSING PROPERTIES OF Cu-DOPED ZINC OXIDE

2002 ◽  
Vol 16 (01n02) ◽  
pp. 314-321 ◽  
Author(s):  
CHIN HOCK ONG ◽  
JIAN HUI WANG ◽  
HAO GONG ◽  
H. S. O. CHAN
Keyword(s):  
Zinc Oxide ◽  
Structural Properties ◽  
Gas Sensing ◽  
Rf Magnetron Sputtering ◽  
Columnar Structure ◽  
X Ray Diffraction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Residual Strains ◽  
Nano Crystal

Copper doped Zinc Oxide thin films are prepared by RF magnetron sputtering. The films are characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and other techniques. It is found that the films are composed of nano-crystal grains with typical columnar structure. The structural properties, such as preferred orientation, residual strains exist in the films, and grains size were studied. Moreover, the porous structure that related with the surface morphology of the films was discussed as it has relationship with the gas sensing property. Gas sensing property of these films was studied with the understanding of structural properties. The films were tested with NO gas. The sensitivity of the films was studied through the discussions of films structures.

Optical And Structural properties of Vertical Aligned Self-Assembled InAs Quantum Dots Multilayers

2001 ◽  
Vol 676 ◽  
Author(s):  
J. C. González ◽  
M. I. N. da Silva ◽  
W. N. Rodrigues ◽  
F. M. Matinaga ◽  
R. Magalhaes-Paniago ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Structural Properties ◽  
Molecular Beam ◽  
X Ray Diffraction ◽  
Inas Quantum Dots ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Self Assembled

ABSTRACTIn this work, we report optical and structural properties of vertical aligned self-assembled InAs quantum dots multilayers. The InAs quantum dots samples were grown by Molecular Beam Epitaxy. Employing Atomic Force Microscopy, Transmission Electron Microscopy, and Gracing Incident X-ray Diffraction we have studied the structural properties of samples with different number of periods of the multiplayer structure, as well as different InAs coverage. The optical properties were studied using Photoluminescence spectroscopy.

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