scholarly journals Graphene prepared on SiC by chemical vapor deposition process at low temperature

2019 ◽  
Vol 70 (4) ◽  
pp. 329-331
Author(s):  
Petr Machac

Abstract Graphene preparation by the method of chemical vapour deposition on SiC substrates is described. Despite very low growth temperature (1080 °C) and with use of methane atmosphere, carbon layers in the form of multi-layer graphene were prepared. Graphene quality was verified by means of available analytical methods: Raman spectroscopy, X-ray photoelectron spectroscopy, Van der Paw method.

2000 ◽  
Vol 611 ◽  
Author(s):  
Akira Izumi ◽  
Hidekazu Sato ◽  
Hideki Matsumura

ABSTRACTThis paper reports a procedure for low-temperature nitridation of silicon dioxide (SiO2) surfaces using species produced by catalytic decomposition of NH3 on heated tungsten in catalytic chemical vapor deposition (Cat-CVD) system. The surface of SiO2/Si(100) was nitrided at temperatures as low as 200°C. X-ray photoelectron spectroscopy measurements revealed that incorporated N atoms are bound to Si atoms and O atoms and located top-surface of SiO2.


2002 ◽  
Vol 749 ◽  
Author(s):  
Kouichi Takayama ◽  
Shigeo Ohshio ◽  
Hidetoshi Saitoh

ABSTRACTChemical-vapor-deposition of titanium tetra-isopropoxide (TTIP) under the atmosphere at low temperature has been conducted. The structure of the obtained films was assessed using Fourier transform infrared spectroscopy, X-ray diffractometry and Raman spectroscopy. These analyses indicated that amorphous TiOxHy films were obtained at gas temperatures in the range of 150–300 °C, and crystalline anatase-TiO2 film was formed at 350 °C. This distinction is accounted for by plausible chemical reactions as follows; the hydroxyl reaction of TTIP below 350 °C promotes the formation of the amorphous TiOxHy. As the temperature goes up to 350 °C, dehydrogenation of the TiOxHy films promotes to form crystalline TiO2. Also the obtained amorphous films were annealed for 10 min under the atmosphere in assessing the transformation proceeding in the solid state. The structural change is shown at 350 °C, indicating that the crystalline phase would be formed via dehydrogenation and polymerization on the surface of the amorphous phase under the atmosphere. The crystal size of the annealed films was evaluated in assessment for the transformation.


Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3363
Author(s):  
Chi Zhang ◽  
Majiaqi Wu ◽  
Pengchang Wang ◽  
Maoliang Jian ◽  
Jianhua Zhang ◽  
...  

In this paper, the environmental stability of silicon nitride (SiNx) films deposited at 80 °C by plasma-enhanced chemical vapor deposition was studied systematically. X-ray photoelectron spectroscopy and Fourier transform infrared reflection were used to analyze the element content and atomic bond structure of the amorphous SiNx films. Variation of mechanical and optical properties were also evaluated. It is found that SiNx deposited at low temperature is easily oxidized, especially at elevated temperature and moisture. The hardness and elastic modulus did not change significantly with the increase of oxidation. The changes of the surface morphology, transmittance, and fracture extensibility are negligible. Finally, it is determined that SiNx films deposited at low-temperature with proper processing parameters are suitable for thin-film encapsulation of flexible devices.


2020 ◽  
Vol 8 (6) ◽  
pp. 2061-2065

The presence of active catalyst during graphene growth by alcohol catalytic chemical vapour deposition is a compulsory. This study is aimed to validate the effect of annealing temperature for the formation of active cobalt oxide (Co3O4 ) film on the graphene growth by alcohol catalytic chemical vapour deposition technique. Active Co3O4 film was prepared on silicon wafers by sol-gel process, using cobalt acetate tetrahydrate as the precursor compound and absolute ethanol as the solvent. The active Co3O4 phase was achieved by annealing process at 450, 500, 550 and 600 °C. The graphene is grown from active Co3O4 film under 900 °C of chemical vapor deposition (CVD) processing temperature for 5 minutes. The obtained Co3O4 was characterized by x-ray diffraction and Raman spectroscopy. The as-grown graphene from active Co3O4 film annealed at 450 ⁰C was characterized by Raman spectroscopy and field emission scanning electron microscope (FESEM). The results demonstrate that spinel type cubic structure of Co3O4 could be produced at the varied annealing temperatures but the optimum XRD result was at 500 ⁰C annealing temperature. The presence of active Co3O4 phase was supported with the exhibited peaks of four Raman-active phonon modes in the Raman spectra. The quality of as-grown graphene determined from the ratio of 2D-band over G-band intensities is 1.010; an indication of few layers of graphene. Active Co3O4 film is able to produce good quality of graphene comparable with Ni and Cu catalysts. And graphene can be used in many devices, including electronic device, energy storage device, power device, and others.


2016 ◽  
Vol 18 (32) ◽  
pp. 22160-22167 ◽  
Author(s):  
K. Ganesan ◽  
Subrata Ghosh ◽  
Nanda Gopala Krishna ◽  
S. Ilango ◽  
M. Kamruddin ◽  
...  

Defects in planar and vertically oriented nanographitic structures (NGSs) synthesized by plasma enhanced chemical vapor deposition (PECVD) have been investigated using Raman and X-ray photoelectron spectroscopy.


Nanomaterials ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 109
Author(s):  
Sandra Rodríguez-Villanueva ◽  
Frank Mendoza ◽  
Alvaro A. Instan ◽  
Ram S. Katiyar ◽  
Brad R. Weiner ◽  
...  

We report the first direct synthesis of graphene on SiO2/Si by hot-filament chemical vapor deposition. Graphene deposition was conducted at low pressures (35 Torr) with a mixture of methane/hydrogen and a substrate temperature of 970 °C followed by spontaneous cooling to room temperature. A thin copper-strip was deposited in the middle of the SiO2/Si substrate as catalytic material. Raman spectroscopy mapping and atomic force microscopy measurements indicate the growth of few-layers of graphene over the entire SiO2/Si substrate, far beyond the thin copper-strip, while X-ray photoelectron spectroscopy and energy-dispersive X-ray spectroscopy showed negligible amounts of copper next to the initially deposited strip. The scale of the graphene nanocrystal was estimated by Raman spectroscopy and scanning electron microscopy.


1994 ◽  
Vol 338 ◽  
Author(s):  
Y. Tao ◽  
D. Landheer ◽  
J.-M. Baribeau ◽  
J. E. Hulse ◽  
D.-X. Xu ◽  
...  

ABSTRACTThe effect of power on the properties of SiO2 films produced by direct plasma-enhanced chemical vapor deposition using nitrous oxide and silane with high helium dilution has been investigated. As the power increases the p-etch rate decreases while the frequency of the Si-O-Si stretching vibration measured by Fourier transform infra-red spectroscopy increases. However the refractive index of the films measured by ellipsometry is almost constant as is the electron density measured by low-angle x-ray reflection, indicating that the structural changes of the film with power do not relate to bulk density changes. The x-ray and ellipsometry measurements indicate the existence of a transitional layer with monolayer dimensions at the Si/SiO2 interface.


2001 ◽  
Vol 16 (6) ◽  
pp. 1838-1849 ◽  
Author(s):  
Kanchana Vydianathan ◽  
Guillermo Nuesca ◽  
Gregory Peterson ◽  
Eric T. Eisenbraun ◽  
Alain E. Kaloyeros ◽  
...  

A chemical vapor deposition process has been developed for titanium dioxide (TiOx) for applications as capacitor dielectric in sub-quarter-micron dynamic random-access memory devices, and as gate insulators in emerging generations of etal-oxide-semiconductor transistors. Studies using the β-diketonate source precursor (2,2,6,6-tetramethyl-3,5-heptanedionato) titanium were carried out to examine the underlying mechanisms that control film nucleation and growth kinetics and to establish the effects of key process parameters on film purity, composition, texture, morphology, and electrical properties. Resulting film properties were thoroughly analyzed by x-ray diffraction, x-ray photoelectron spectroscopy, Rutherford backscattering spectrometry, scanning electron microscopy (SEM), focused-ion-beam SEM, and capacitance–voltage (C–V) measurements. The study resulted in the identification of an optimized process for the deposition of an anatase–rutile TiOx film with a dielectric constant approximately 85 at 1 MHz for a 330-nm thickness, and a leakage current below 2 × 10−8 A/cm2 for bias voltage values up to 3.5 V.


2016 ◽  
Vol 721 ◽  
pp. 258-262 ◽  
Author(s):  
Tatiana Larionova ◽  
Tatiana Koltsova ◽  
Mariya Kozlova ◽  
Vladimir Levitskii ◽  
Ilya Eliseyev ◽  
...  

Graphene grown by chemical vapor deposition on copper and the one transferred to Si/SiO2 substrate were subjected to Ar ion treatment. A combination of X-ray photoelectron spectroscopy and Raman spectroscopy were used for characterization. According to XPS data sample on Si/SiO2 appears less susceptible to sputtering under bombardment. However, the defect concentrations introduced to the transferred graphene reach up the value two orders of magnitude higher than that in as grown graphene on Cu. We attribute this difference to the influence of the non-compensated charge formed on the insulating SiO2 layer under bombardment.


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