MOCVD Growth of Ga(Al)N/InGaN/Ga(Al)N-Heterostructures: Influence of the Buffer Layer Al-Concentration and Growth Duration on the In-Incorporation in InGaN

2001 ◽  
Vol 680 ◽  
Author(s):  
Marco Schowalter ◽  
Brigitte Neubauer ◽  
Andreas Rosenauer ◽  
Dagmar Gerthsen ◽  
Oliver Schön ◽  
...  
Keyword(s):  
Chemical Vapor ◽  
Growth Conditions ◽  
Buffer Layers ◽  
Organic Chemical ◽  
Growth Duration ◽  
Mocvd Growth ◽  
Transmission Electron ◽  
Metal Organic ◽  
Composition Fluctuations ◽  
Organic Chemical Vapor Deposition

ABSTRACTTransmission electron microscopy (TEM) has been applied to analyze the thickness and the In-concentration of InGaN layers in GaN/InGaN/GaN- and AlGaN/InGaN/AlGaN-quantum well (QW) structures. Two series of samples were grown by metal organic chemical vapor deposition varying either only the growth duration for the InGaN QW or by changing the Al- concentration in the buffer layers at unaltered InGaN growth conditions. A rising average In- concentration from 6.5 to 15.4 % and a decreasing growth rate are observed with increasing growth duration. The increase of the Al-concentration in the buffer layers from 0 to 36 % strongly affects the In-incorporation during the InGaN growth, which decreases from 17.5 to 2.5 %. All samples are characterized by an inhomogeneous In-distribution containing In-rich agglomerates with a size of only a few nanometers and less pronounced composition fluctuations on a scale of 100 nm.

Dependence on MOCVD Growth Temperature of The Photoluminescence Properties of ZnSe, ZnTe, and ZnSe(1-x)Te(x) Alloys and ZnSe/ZnTe Superlattices

1992 ◽  
Vol 263 ◽  
Author(s):  
B.E. Ponga ◽  
J. Calas ◽  
M. Averous ◽  
T. Cloitre ◽  
O. Briot ◽  
...  
Keyword(s):  
Low Temperature ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Physical Situation ◽  
Temperature Growth ◽  
Mocvd Growth ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
Ethyl Amine

ABSTRACTIt has been recently shown that high quality ZnSe and ZnTc filns can be grown on GaAs using low temperature growth techniques such as Metal-Organic Chemical Vapor Deposition ( MOCVD). All samples: ZnSe, ZnTe, ZnSc(l−x)Tc(x) epilayers and ZnSe/ZnTc superlattices were grown using a novel zinc precursor, the Tri-Ethyl-Amine Di-Methyl-Zinc, while we used the classical precursors H2Se and Di-Isopropyl-Tellurium for selenium and tellurium. Investigation of the photoluminescence (PL) properties of ZnSc and ZnTe single layers enabled us to optimize the growth conditions of these compounds. The crystal growth conditions for mixed alloys and superlattices were determined by direct comparison to the aspect of low-temperature PL features. Strong PL spectra were obtained from these materials, suggesting us that tellurium has the ability to behave like an iso-clectronic center. At low concentration of tellurium in ZnSe, an interesting physical situation is observed, which we have interpreted in terms of extrinsic exciton “self-trapping” mechanism.

MOCVD Growth of SiC Nanowires Aiming at the Control of their Shape

2007 ◽  
Vol 26-28 ◽  
pp. 657-660 ◽  
Author(s):  
S. Takao ◽  
Hideo Kohno ◽  
Seiji Takeda
Keyword(s):  
Chemical Vapor ◽  
Growth Conditions ◽  
High Yield ◽  
Organic Chemical ◽  
Ni Catalyst ◽  
Silicon Substrates ◽  
Sic Nanowires ◽  
Mocvd Growth ◽  
Transmission Electron ◽  
Metal Organic

We report the growth of silicon carbide (SiC) nanowires on silicon substrates by metal organic chemical vapor deposition (MOCVD) using dimethylvinyllsilane [CH2CHSi(CH3)Cl2] as a source gas and metal catalysts of Ni and Fe. Various growth conditions such as the growth temperature and the pressure of the source gas are examined to achieve high yield growth of SiC nanowires and to control their shape. No SiC nanowires were formed when using Fe. In contrast, by using Ni catalyst, numerous SiC nanowires of about 30 nm thick can be grown at the pressure of the source gas of 30 Pa at 800 °C. Their microstructure is revealed by scanning electron microscopy (SEM) and transmission electron microscope (TEM).

Novel Design of MOCVD Reactor with Three Radial Inward Flows for Epitaxial Growth of GaN Thin Films

2011 ◽  
Vol 308-310 ◽  
pp. 1037-1040
Author(s):  
Liao Qiao Yang ◽  
Jian Zheng Hu ◽  
Zun Miao Chen ◽  
Jian Hua Zhang ◽  
Alan G. Li
Keyword(s):  
Gas Flow ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Operating Pressure ◽  
Axisymmetric Mode ◽  
Mocvd Reactor ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition ◽  
D Model

In this paper, a novel super large metal organic chemical vapor deposition (MOCVD) reactor with three inlets located on the periphery of reactor was proposed and numerical evaluation of growth conditions for GaN thin film was characterized. In this design, the converging effects of gas flow in the radial direction could counterbalance the dissipation of metal organics source. CFD was used for the mathematical solution of the fluid flow, temperature and concentration fields. A 2-D model utilizing axisymmetric mode to simulate the gas flow in a MOCVD has been developed. The growth of GaN films using TMGa as a precursor, hydrogen as carrier gas was investigated. The effects of flow rates, mass fraction of various species, operating pressure, and gravity were analyzed and discussed, respectively. The numerical simulation results show all the fields distributions were in an acceptable range.

scholarly journals The Optimization of Interfaces in InAsSb/InGaAs Strained-Layer Superlattices grown by Metal-Organic Chemical Vapor Deposition

1994 ◽  
Vol 340 ◽  
Author(s):  
R. M. Biefeld ◽  
K. C. Baucom ◽  
S. R. Kurtz
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Interface Layer ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Strained Layer ◽  
Strained Layer Superlattice ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

ABSTRACTWe have prepared InAsSb/InGaAs strained-layer superlattice (SLS) semiconductors by metal-organic chemical vapor deposition (MOCVD) using a variety of growth conditions. The presence of an InGaAsSb interface layer is indicated by the x-ray diffraction patterns. The optimized growth conditions involved the use of low pressure, short purge times between the growth of the layers, and no reactant flow during the purges. We used MOCVD to prepare an optically pumped, single heterostructure InAsSb/InGaAs SLS / InPSb laser which emitted at 3.9 μm with a maximum operating temperature of approximately 100 K.

Thin films for superconducting electronics: Precursor performance issues, deposition mechanisms, and superconducting phase formation-processing strategies in the growth of Tl2Ba2CaCu2O8 films by metal-organic chemical vapor deposition

1997 ◽  
Vol 12 (5) ◽  
pp. 1214-1236 ◽  
Author(s):  
Bruce J. Hinds ◽  
Richard J. McNeely ◽  
Daniel B. Studebaker ◽  
Tobin J. Marks ◽  
Timothy P. Hogan ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Vapor Pressure ◽  
Vapor Deposition ◽  
Film Growth ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Organic Chemical ◽  
Metal Organic ◽  
Organic Chemical Vapor Deposition

Epitaxial Tl2Ba2CaCu2O8 thin films with excellent electrical transport characteristics are grown in a two-step process involving metal-organic chemical vapor deposition (MOCVD) of a BaCaCuO(F) thin film followed by a postanneal in the presence of Tl2O vapor. Vapor pressure characteristics of the recently developed liquid metal-organic precursors Ba(hfa)2 • mep (hfa = hexafluoroacetylacetonate, mep = methylethylpentaglyme), Ca(hfa)2 • tet (tet = tetraglyme), and the solid precursor Cu(dpm)2 (dpm = dipivaloylmethanate) are characterized by low pressure thermogravimetric analysis. Under typical film growth conditions, transport is shown to be diffusion limited. The transport rate of Ba(hfa)2 • mep is demonstrated to be stable for over 85 h at typical MOCVD temperatures (120 °C). In contrast, the vapor pressure stability of the commonly used Ba precursor, Ba(dpm)2, deteriorates rapidly at typical growth temperatures, and the decrease in vapor pressure is approximately exponential with a half-life of ∼9.4 h. These precursors are employed in a low pressure (5 Torr) horizontal, hot-wall, film growth reactor for growth of BaCaCuO(F) thin films on (110) LaAlO3 substrates. From the dependence of film deposition rate on substrate temperature and precursor partial pressure, the kinetics of deposition are shown to be mass-transport limited over the temperature range 350–650 °C at a 20 nm/min deposition rate. A ligand exchange process which yields volatile Cu(hfa)2 and Cu(hfa) (dpm) is also observed under film growth conditions. The MOCVD-derived BaCaCuO(F) films are postannealed in the presence of bulk Tl2Ba2CaCu2O8 at temperatures of 720–890 °C in flowing atmospheres ranging from 0–100% O2. The resulting Tl2Ba2CaCu2O8 films are shown to be epitaxial by x-ray diffraction and transmission electron microscopic (TEM) analysis with the c-axis normal to the substrate surface, with in-plane alignment, and with abrupt film-substrate interfaces. The best films exhibit a Tc = 105 K, transport-measured Jc= 1.2 × 105 A/cm2 at 77 K, and surface resistances as low as 0.4 mΩ (40 K, 10 GHz).

TEM Study of MOCVD Grown InSb/GaAs Heterostructures with and without TMIn Predeposited Layers

1994 ◽  
Vol 340 ◽  
Author(s):  
L. H. Kuo ◽  
Susan Z. Hua ◽  
L. Salamanca-Riba ◽  
D. L. Partin ◽  
L. Green ◽  
...  
Keyword(s):  
Vapor Deposition ◽  
Chemical Vapor ◽  
Organic Chemical ◽  
Threading Dislocations ◽  
High Quality ◽  
Gaas Substrates ◽  
Transmission Electron ◽  
Metal Organic ◽  
Step Growth ◽  
Organic Chemical Vapor Deposition

ABSTRACTHigh quality InSb epilayers were grown on GaAs substrates by metal organic chemical vapor deposition using a two-step growth procedure involving trimethal indium (TMIn) predeposition. From transmission electron microscopy studies, we found that an interdiffusion layer of thickness of 10 Å forms at the interface when the substrate is exposed to TMIn for approximately 6 secs prior to the growth of the InSb filns. Hall mobilities up to σ 52,000 cm2/V-s were obtained at 300 K on a 2.1-μm-thick InSb heteroepitaxial film. In contrast, samples without TMIn predeposition showed polycrystallinity of the InSb films grown on single crystalline GaAs substrates. The effect. of TMNIn predeposition is to minimize the misorientation of the grains, suppress the polycrystallinity, decrease the density of threading dislocations, and increase the electron mobilities in the films. However, we found that too much TMIn predeposition gives rise t.o an intermixing layer at the InSb/GaAs interface which deteriorates the film quality. Details of the effect of the TMIn predeposition on the microstructure of InSb/GaAs with different predeposition times (zero, 6, and 12 secs) are discussed.

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