Synthesis of InN nanowires grown on droplets formed with Au and self-catalyst on Si(111) by using metalorganic chemical vapor deposition

2010 ◽  
Vol 25 (9) ◽  
pp. 1778-1783 ◽  
Author(s):  
Seok-Hyo Yun ◽  
Suthan Kissinger ◽  
Don Wook Kim ◽  
Jun-Ho Cha ◽  
Yong-Ho Ra ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Chamber Pressure ◽  
Gas Flow Rate ◽  
Metalorganic Chemical

We demonstrated the growth of indium nitride (InN) nanowires on Si(111) substrates by metalorganic chemical vapor deposition without the use of any intermediate GaN or AlN buffer layer. The InN nanowires were grown by forming the Au + In droplets and In droplets on the Au- and In-coated Si substrate. The growth conditions such as chamber pressure, chamber temperature, reaction gas flow rate, and carrier gas flow rate were optimized to yield nanowires free from contamination. Depending on the growth parameters different growth regimes for the InN nanowires were identified. The strength of self-catalytic route has been highlighted. The morphology and microstructures of samples were characterized by x-ray diffraction and scanning electron microscopy (SEM). The transmission electron microscopy and SEM investigations showed that the InN nanowires are single crystals with diameters ranging from 40 to 400 nm, and lengths up to 3 µm. Photoluminescence spectra of the InN nanowires showed a strong broad emission peak at 0.77 eV.

Chemical vapor deposition parameters dependent length control of hexagonal graphene

2016 ◽  
Vol 231 (6) ◽  
pp. 1187-1196
Author(s):  
Hatem Abuhimd
Keyword(s):  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Chamber Pressure ◽  
Gas Flow Rate ◽  
Production Scale ◽  
Surface Graph ◽  
Deposition Parameters

This paper presents a process metamodel-based artificial neural network full factorial experimental design and analysis to study the yield of lengthy hexagonal graphene grown by chemical vapor deposition. All of the process variables of chemical vapor deposition such as temperature, pressure, and gas flow rate under the study played a role in influencing hexagonal graphene length; the current study investigated their main effects and interactions. The metamodel-based analysis demonstrates that the hydrocarbon flow rate and the pressure are the most statistically significant factors that influence the length of hexagonal graphene. In particular, minimum and maximum values of the chamber pressure are not significant in terms of the concentrating effect they may have on the flowing mixture of gases with very small flow rate, i.e. 50 sccm. At the highest flow rate of 400 sccm, the chamber pressure stepped up to 764 Torr, which can support the growth reaction to the extent that the resultant hexagonal graphene length of 900 µm can be achieved. However, the two level effect of the flow rate can optimize the length to 990 µm and ≈1390 µm at 700 Torr and 764 Torr, respectively. In addition, the response surface graph confirms the factors of significance and adds that higher flow with lower pressure will consistently yield tall hexagonal graphene. We found that gas flow rate is the most significant of the control variables and only the optimum value of the gas flow rate of 225 sccm can ensure the growth of tall hexagonal graphene. We also found that the interaction of flow rate with temperature of the gases in the chamber is extremely significant to the quality of output. Outcomes of this investigation are beneficial for moving close to producing hexagonal graphene on production scale for future applications.

Nanocrystalline ZrO2thin films on silicon fabricated by pulsed-pressure metalorganic chemical vapor deposition (PP-MOCVD)

2008 ◽  
Vol 23 (8) ◽  
pp. 2202-2211 ◽  
Author(s):  
L. Ramirez ◽  
M.L. Mecartney ◽  
S.P. Krumdieck
Keyword(s):  
Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Tetragonal Zirconia ◽  
Chemical Vapor ◽  
Optimal Growth ◽  
Stages Of Growth ◽  
Average Grain Size ◽  
Metalorganic Chemical

ZrO2films deposited on silicon (100) substrates using pulsed-pressure metalorganic chemical vapor deposition (PP-MOCVD) with zirconium n-propoxide (ZnP) Zr(OC3H7)4were dense and fully crystalline for substrate temperatures of 500 to 700 °C. Film thicknesses were 40 to 815 nm thick, measured after growth using ellipsometry and scanning electron microscopy (SEM). The growth rate was between 0.1 μm/h at 500 °C and 1 μm/h at 700 °C. Transmission electron microscopy (TEM) and x-ray diffraction (XRD) indicated an average grain size of 10 to 20 nm. There was a random orientation of cubic/tetragonal zirconia at the highest experimental temperature of 700 °C. SEM and atomic force microscopy (AFM) was used to characterize island height of discontinuous films in the initial stages of growth where defects in the substrate caused preferred nucleation of isolated particles. At later stages of growth, the average surface roughness of continuous films was 30 nm, which revealed a more uniform growth had developed. A growth model is proposed, and optimal growth conditions are suggested for targeted microstructures of ZrO2films.

Fabrication and characterization of ferroelectric Pb(ZrxTi1–x)O3 thin films by metalorganic chemical vapor deposition

1999 ◽  
Vol 14 (2) ◽  
pp. 487-493 ◽  
Author(s):  
Han Sang Song ◽  
Tae Song Kim ◽  
Chang Eun Kim ◽  
Hyung Jin Jung
Keyword(s):  
Thin Films ◽  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Pyrochlore Phase ◽  
Chemical Vapor ◽  
Spectra Analysis ◽  
Pzt Thin Films ◽  
Metalorganic Chemical

Ferroelectric Pb(Zr, Ti)O3 (PZT) thin films were grown on Pt/Ti/SiO2/Si, RuO2/Pt/Ti/SiO2/Si, and Pt/MgO substrates at the substrate temperature of 600 °C by the metalorganic chemical vapor deposition (MOCVD) method. Pb(C11H19O2)2(Pb(DPM)2), Ti(OiC3H7)4, and Zr(OtC4H9)4 as source material and Ar and O2 as a carrier gas and oxidizing agent were selected, respectively. In order to investigate the effect of Zr and Ti component changes on the growth aspect of PZT thin films, Zr and Ti source materials were varied by controlling Zr and Ti flow rate. From the Rutherford backscattering spectroscopy (RBS) measurement, it was confirmed that the composition of the films, particularly Pb content, changed with the increasing Zr flow rate. In addition, the x-ray diffraction (XRD) spectra analysis showed the existence of a Pb-deficient pyrochlore phase as well as ZrO2 as a secondary phase. From these results, it is believed that the higher Zr partial pressure in the gas phase reduces the sticking of the Pb precursor to the substrate. The film with Pb:Zr:Ti = 1:0.42:0.58 showed a dielectric constant of 816 at 1 MHz. The spontaneous polarization, remanent polarization, and coercive field measured from the RT66A by applying 3.5 V were 44.1 μC/cm2, 24.4 μC/cm2, and 59.6 kV/cm, respectively. The fatigue analysis of PZT thin films with Pb:Zr:Ti = 1:0.42:0.58 at an applied voltage of Vp-p = 5.4 V showed 40% degradation on the basis of initial polarization value after 109 cycles.

Microstructures of GaN Films Grown on a LiGaO2 New Substrate by Metalorganic Chemical Vapor Deposition

1997 ◽  
Vol 468 ◽  
Author(s):  
Jing-Hong Li ◽  
Olga M. Kryliouk ◽  
Paul H. Holloway ◽  
Timothy J. Anderson ◽  
Kevin S. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Lattice Mismatch ◽  
Chemical Vapor ◽  
Threading Dislocations ◽  
Transmission Electron ◽  
Metalorganic Chemical

ABSTRACTMicrostructures of GaN films grown on the LiGaO2 by metalorganic chemical vapor deposition (MOCVD) have been characterized by transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM). TEM and HRTEM results show that high quality single-crystal wurtzite GaN films have been deposited on the LiGaO2 and that the GaN film and the LiGaO2 have the following orientation relationship: (2110)(0002)GaN ̂ (002)LiGaO2 ^ 5–8°. A higher density of threading dislocations and stacking faults have been observed near the GáN/LiGaO2 interface, even though the lattice mismatch of GaN to LiGaO2 is only ∼1%. Threading dislocations with burgers vector b=<0001> and b=a/3<1120> are predominant in the GaN films. Also the GaN films contain some columnar inversion domain boundaries (IDBs). Both TEM and HRTEM results reveal that there is an unexpected amorphous or nano-crystalline inter-layer between the GaN and the LiGaO2 with a thickness of 50–100 nm.

Effects of Reaction Conditions on MoS2 Thin Film Formation Synthesized by Chemical Vapor Deposition using Organic Precursor

MRS Advances ◽  
2016 ◽  
Vol 2 (29) ◽  
pp. 1533-1538 ◽  
Author(s):  
S. Ishihara ◽  
Y. Hibino ◽  
N. Sawamoto ◽  
T. Ohashi ◽  
K. Matsuura ◽  
...  
Keyword(s):  
Thin Film ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Film Formation ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Axis Orientation

ABSTRACTMolybdenum disulfide (MoS2) thin films were fabricated by two-step chemical vapor deposition (CVD) using (t-C4H9)2S2 and the effects of temperature, gas flow rate, and atmosphere on the formation were investigated in order to achieve high-speed low-temperature MoS2 film formation. From the results of X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) investigations, it was confirmed that c-axis orientation of the pre-deposited Mo film has a significant involvement in the crystal orientation after the reaction low temperature sulfurization annealing and we successfully obtained 3 nm c-axis oriented MoS2 thin film. From the S/Mo ratios in the films, it was revealed that the sulfurization reaction proceeds faster with increase in the sulfurization temperature and the gas flow rate. Moreover, the sulfurization under the H2 atmosphere promotes decomposition reaction of (t-C4H9)2S2, which were confirmed by XPS and density functional theory (DFT) simulation.

High Quality InP Epitaxial Growth Using Flow Rate Modulation Metalorganic Chemical Vapor Deposition

1997 ◽  
Vol 08 (04) ◽  
pp. 575-586
Author(s):  
M. K. Lee ◽  
C. C. Hu
Keyword(s):  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Growth Conditions ◽  
Atomic Scale ◽  
Optimum Growth ◽  
Rate Modulation ◽  
Metalorganic Chemical

The characteristics of modified flow rate modulation metalorganic chemical deposition is studied. From observation with the atomic force microscope, the flatness of a InP homoepitaxial layer is improved to atomic scale by phosphine modulation metalorganic chemical vapor deposition. The full width at half maximum 5.6 meV of photoluminescence at 77 K can be achieved under optimum growth conditions. The satellite peak around the near band emission can also be reduced to a negligible quantity under optimum growth conditions. Also, MFME can improve the electrical characteristics of the epilayer with higher electron mobility and lower compensation ratio.

Structural and Optical Properties of ZnO Nanotetrapods Deposited by Thermal Chemical Vapor Deposition with Different Gas Flow Rate

2015 ◽  
Vol 1109 ◽  
pp. 456-460
Author(s):  
Najwa Ezira Ahmed Azhar ◽  
Shafinaz Sobihana Shariffudin ◽  
Aimi Bazilah Rosli ◽  
A.K.S. Shafura ◽  
Mohamad Rusop
Keyword(s):  
Optical Properties ◽  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Structural And Optical Properties ◽  
Thermal Chemical Vapor Deposition ◽  
Yellow Orange

ZnO nanotetrapod with different oxygen flow rate was prepared by thermal chemical vapor deposition. We have successfully deposited ZnO nanotetrapod on synthesis Zn powder using double furnace with argon (Ar) and oxygen (O2) gas as source material. In this study, we report the effect of different gas flow rate (5 sccm to 15 sccm) on structural and optical properties of the ZnO nanotetrapod. The morphology of ZnO nanotetrapods were analyzed by field emission scanning electron microscope (FE-SEM). It exhibits the length of the nanotetrapods arm decrease with increased of flow rate and diameter of nanotetrapod in range 30 nm to 90 nm. The optical properties were determined through XRD and photoluminescence with 2θ (30o to 80o) and wavelength 350 nm to 620 nm respectively. PL spectra show that the UV emission centred at 380 nm while yellow-orange emission centred at 540 nm.

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