Effect of Precursor Supply on (100) and (001) Orientations of α-Al2O3 Film Prepared by Laser CVD

2012 ◽  
Vol 508 ◽  
pp. 3-6 ◽  
Author(s):  
Kadokura Hokuto ◽  
Akihiko Ito ◽  
Teiichi Kimura ◽  
Takashi Goto
Keyword(s):  
Cross Section ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Laser Chemical Vapor Deposition ◽  
Evaporation Temperature ◽  
Oxygen Gas ◽  
Laser Cvd ◽  
Precursor Supply

Α-Al2O3 Films Were Prepared by Laser Chemical Vapor Deposition and the Effects of Precursor Evaporation Temperature (Tvap) and Oxygen Gas Flow Rate (FRo) on Phase and Orientation of Al2o3 Films Were Investigated. at Tvap = 413 K, (100)-Oriented α-Al2O3 and θ-Al2O3 Were Codeposited. the Amount of θ-Al2O3 Increased with Increasing FRo. at Tvap = 433–443 K, α-Al2O3 Films Showed a (001) Orientation. (100)- and (001)-Oriented α-Al2O3 Films Had a Rectangular- and Hexagonal-Shaped Grains, Respectively, and Showed a Columnar in Cross Section. Grain Size of (100)- and (001)-Oriented α-Al2O3 Films Decreased from 10 to 2 μm with Increasing FRo from 0.085 to 0.85 Pa m3 s−1. Deposition Rate Increased from 100 to 300 μm h−1 with Increasing Tvap from 413 to 443 K.

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.

CVD Processing

MRS Bulletin ◽  
1995 ◽  
Vol 20 (1) ◽  
pp. 45-47 ◽  
Author(s):  
Toshio Hirai
Keyword(s):  
Vapor Deposition ◽  
Gas Flow ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Mixture Ratio ◽  
Gradient Materials ◽  
Cvd Method ◽  
Functionally Gradient ◽  
Composition And Structure ◽  
Source Materials

Various methods are used in functionally gradient materials technology to control the composition and structure of a composite.The chemical vapor deposition (CVD) method yields a deposit with source gases by applying variou s forms of energy (heat, light, plasma, etc.) to the gases after they are introduced into a CVD reactor. Hydride, bromide, and chloride are generally used for source materials. By continually changing the mixture ratio of source gases or by controlling the CVD conditions such as deposition temperatures, gas pressure, and gas-flow rate, CVD permits relatively easy syntheses of various FGMs (to a maximum thickness on the order of a centimeter).

Preparation of Stoichiometric TiNx Films by Laser CVD with Metalorganic Precursor

2011 ◽  
Vol 239-242 ◽  
pp. 318-321
Author(s):  
Yan Sheng Gong ◽  
Wei Zhou ◽  
Rong Tu ◽  
Takashi Goto
Keyword(s):  
Chemical Vapor Deposition ◽  
Cross Section ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Laser Power ◽  
Single Phase ◽  
Heating Temperature ◽  
Chemical Vapor ◽  
Laser Cvd ◽  
Source Materials

Nearly stoichiometric TiNxfilms were deposited on Al2O3substrates by laser enhanced chemical vapor deposition (CVD) with tetrakis (diethylamido) titanium (TDEAT) and ammonia as the source materials. Emphases were given on the effects of laser power (PL) and pre-heating temperature (Tpre) on the composition and deposition rate of TiNxfilms. Single phase of TiNxfilms with columnar cross section were obtained. The ratio of N to Ti in TiNxfilms increased with increasingPLand was close to stoichiometric atPL> 150 W. The deposition rate of TiNxfilms with a depositing area of 300 mm2was about 18-90 µm/h, which decreased with increasingPLandTpre.

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.

Preparation of c-Axis-Oriented Y2Ba4Cu7O15-δ Films by Laser CVD with Ultrasonically Nebulized Precursor

2012 ◽  
Vol 508 ◽  
pp. 207-210
Author(s):  
Akihiko Ito ◽  
Mitsutaka Sato ◽  
Takashi Goto
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Deposition Temperature ◽  
Single Phase ◽  
Chemical Vapor ◽  
Precursor Concentration ◽  
Laser Chemical Vapor Deposition ◽  
Axis Orientation ◽  
Liquid Precursor ◽  
Laser Cvd

C-Axis-Oriented Y2Ba4Cu7O15-δ (Y247) Films Were Prepared on Multilayer-Coated Hasterolly Tape Substrate by Laser Chemical Vapor Deposition with Ultrasonically Nebulized Liquid Precursor. At a Low Precursor Concentration of 0.01 mol l−1 and Deposition Temperature of 933 K, Single-Phase Y247 Film with Significant c-Axis Orientation Was Obtained. At a Precursor Concentration of 0.1 mol l−1 and Deposition Temperature 983 K, a-Axis-Oriented YBa2Cu3O7-δ (Y123) Was Codeposited with C-Axis Oriented Y247 Film.

Growth Promotion and Etching of Carbon Nanotubes by Carbon Dioxide in Chemical Vapor Deposition using Methane Gas

2007 ◽  
Vol 1057 ◽  
Author(s):  
Yoshiyuki Suda ◽  
Junichi Takayama ◽  
Takeshi Saito ◽  
Atsushi Okita ◽  
Junji Nakamura ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Flow Rate ◽  
Vapor Deposition ◽  
Gas Flow ◽  
Growth Promotion ◽  
Chemical Vapor ◽  
Gas Flow Rate ◽  
Preferential Growth ◽  
Ar Gas ◽  
Walled Cnts

ABSTRACTWe report the effect of CO2 addition to CO4 gas on carbon nanotube (CNT) growth by chemical vapor deposition. CO2 gas was introduced during the growth of CNTs on Fe0.05Mo0.025MgO0.925 and Ni0.05Mo0.025MgO0.925 catalysts by CO4 gas at a temperature of 800–850°C, and its concentration in a fraction of the gas flow rate was varied from 5×10−3 to 50%. In the experimental condition of the preferential growth of multi-walled CNTs, the carbon yield and the G/D ratio in the Raman spectra of the CNTs grown in 10%-CO2/CO4 were slightly higher than that grown in CO4 only. However, CNTs hardly grew when the CO2 concentration was more than 10%. We then prepared CO2 gas diluted with Ar gas (CO2/Ar) and varied its flow rate between 0 and 10 sccm. As the CO2/Ar gas flow rate was increased, the number of RBM peaks decreased even though the G/D ratio gradually decreased. The decrease in the RBM intensities of CNTs on the FeMoMgO catalyst was more significant than that of NiMoMgO.

Sign in / Sign up

Export Citation Format

Share Document