Synthesizing Nanocrystalline Carbon Thin Films by Hot Filament Chemical Vapor Deposition and Controlling Their Microstructure

2002 ◽  
Vol 17 (7) ◽  
pp. 1820-1833 ◽  
Author(s):  
S. Gupta ◽  
B. R. Weiner ◽  
G. Morell

Nanocrystalline carbon (n-C) thin films were deposited on Mo substrates using methane (CH4) and hydrogen (H2) by the hot-filament chemical vapor deposition (HFCVD) technique. Process parameters relevant to the secondary nucleation rate were systematically varied (0.3–2.0% methane concentrations, 700–900 °C deposition temperatures, and continuous forward and reverse bias during growth) to study the corresponding variations in film microstructure. Standard nondestructive complementary characterization tools such as scanning electron microscopy, x-ray diffraction, atomic force microscopy, Raman spectroscopy, and x-ray photoelectron spectroscopy were utilized to obtain a coherent and comprehensive picture of the microstructure of these films. Through these studies we obtained an integral picture of the material grown and learned how to control key material properties such as surface morphology (faceted versus evenly smooth), grain size (microcrystalline versus nanocrystalline), surface roughness (from rough 150 rms to smooth 70 rms), and bonding configuration (sp3 C versus sp2 C), which result in physical properties relevant for several technological applications. These findings also indicate that there exist fundamental differences between HFCVD and microwave CVD (MWCVD) for methane concentrations above 1%, whereas some similarities are drawn among films grown by ion-beam assisted deposition, HFCVD assisted by low-energy particle bombardment, and MWCVD using noble gas in replacement of traditionally used hydrogen.

2006 ◽  
Vol 321-323 ◽  
pp. 1687-1690 ◽  
Author(s):  
Hee Joon Kim ◽  
Dong Young Jang ◽  
Prem Kumar Shishodia ◽  
Akira Yoshida

In the paper, zinc oxide (ZnO) thin films are deposited by plasma enhanced chemical vapor deposition (PECVD) at different substrate temperatures. The ZnO films are characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The analysis results indicate that highly crystalline films with high orientation can be obtained at a substrate temperature of 300 oC with 50 ml/min flow rate from Diethylzinc (DEZ). Furthermore, the investigation of optical property shows that ZnO films are transparent, and the peak transmittance in the visible region is as high as 85%.


PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0259216
Author(s):  
Satoru Yoshimura ◽  
Satoshi Sugimoto ◽  
Takae Takeuchi ◽  
Kensuke Murai ◽  
Masato Kiuchi

We proposed an experimental methodology for producing films on substrates with an ion beam induced chemical vapor deposition (IBICVD) method using hexamethyldisilazane (HMDS) as a source material. In this study, both HMDS and ion beam were simultaneously injected onto a Si substrate. We selected Ar+ and N+ as the ion beam. The energy of the ion beam was 101 eV. Temperature of the Si substrate was set at 540 °C. After the experiments, films were found to be deposited on the substrates. The films were then analyzed by Fourier transform infrared (FTIR) spectroscopy, stylus profilometer, X-ray diffraction, atomic force microscopy, and X-ray photoelectron spectroscopy (XPS). The FTIR and XPS results showed that silicon carbide films containing small amount of nitrogen were formed when Ar+ ions were injected in conjunction with HMDS. On the other hand, in the cases of N+ ion beam irradiation, silicon nitride films involving small amount of carbon were formed. It was noted that no film deposition was observed when HMDS alone was supplied to the substrates without any ion beam injections.


2011 ◽  
Vol 1313 ◽  
Author(s):  
Lamartine Meda

ABSTRACTLithium phosphorus oxynitride (Lipon) thin films have been deposited by a plasmaenhanced metalorganic chemical vapor deposition (PE-MOCVD) method using triethyl phosphate [(CH2CH3)3PO4] and lithium tert-butoxide [(LiOC(CH3)3] precursors. Growth rates were between 100 and 415 Å/min, and thicknesses ranged from 1 to 2.5 μm. X-ray powder diffraction showed that the films were amorphous, and X-ray photoelectron spectroscopy revealed approximately 6.9 at.% carbon in the films. The ionic conductivity of Lipon was measured using electrochemical impedance spectroscopy (EIS) and approximately 1.02 μS/cm was obtained, which is consistent with the ionic conductivity of Lipon deposited by radio frequency magnetron sputtering of Li3PO4 targets. An all-solid-state thin-film lithium microbattery such as Li/Lipon/LiCoO2/Au/substrate was successfully fabricated with Lipon deposited by PE-MOCVD. The battery has a capacity of ca. 22 μAh/cm2μm.


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.


2004 ◽  
Vol 822 ◽  
Author(s):  
Davide Barreca ◽  
Elza Bontempi ◽  
Laura E. Depero ◽  
Cinzia Maragno ◽  
Eugenio Tondello

AbstractNanocrystalline SnO2 thin films were synthesized by Chemical Vapor Deposition on Si(100) and Al2O3 substrates using bis(diethylamino)dimethylstannane(IV) [(CH3)2Sn(N(C2H5)2)2] as precursor. Film growth was performed at 400-500°C in an O2(H2O)+N2 atmosphere, with the aim of studying the effects of the synthesis conditions on the coating properties. The sample chemical composition and surface morphology were analyzed by X-ray Photoelectron Spectroscopy (XPS) and Atomic Force Microscopy (AFM), while their structural features were investigated by Glancing Incidence X-ray Diffraction (GIXRD) and X-ray Reflectivity (XRR). In this paper, the attention is focused on the interplay between film nanostructure and morphology, with particular regard to the influence of the growth surface.


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.


1994 ◽  
Vol 344 ◽  
Author(s):  
Prasad N. Gadgil

AbstractA three member ring compound propylene sulfide, C3H6S is employed as a sulfur source for the Metalorganic Chemical Vapor Deposition (MOCVD) of stoichiometric thin films of iron pyrite (FeS2). Iron pentacarbonyl Fe(CO)5, a liquid, was precursor for iron. Propylene sulfide, (PS) a liquid ( b. p. = 72–75 °C, v. p. ∼ 87 torr @ 20°C ) decomposes cleanly and quantitatively as S2 and C3H6 (propylene) above 250°C. Deposition of thin films of pyrite and their analysis by X-ray diffraction and Mossbauer and X-ray Photoelectron spectroscopy is described. Liquid state, long term stability, clean and low temperature generation of active S2 species in vapor phase and gaseous by product C3H6 which can be burned to CO2 and H2O are the key advantages offered by propylene sulfide as a sulfur source.


Sign in / Sign up

Export Citation Format

Share Document