Determining the sp2/sp3 bonding concentrations of carbon films using X-ray absorption spectroscopy

2008 ◽  
Vol 86 (12) ◽  
pp. 1401-1407 ◽  
Author(s):  
T Hamilton ◽  
R G Wilks ◽  
M V Yablonskikh ◽  
Q Yang ◽  
M N Foursa ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Microwave Plasma ◽  
Nitrogen Concentration ◽  
Chemical Vapour ◽  
Carbon Films ◽  
Silicon Substrates ◽  
X Ray ◽  
Nitrogen Concentrations ◽  
Plasma Chemical Vapour Deposition ◽  
X Ray Absorption

The sp2 bonding concentrations of nitrogen-doped amorphous carbon samples and nanodiamond films were determined from their soft X-ray absorption spectra. The amorphous carbon (a-C) samples were deposited under atmospheres of varying nitrogen concentrations onto polytetrafluoroethylene (PTFE) polymer and silicon substrates. The nanodiamond films were synthesized on silicon substrates in a CH4/H2 gas mixture by microwave plasma chemical vapour deposition. The sp2 bonding concentrations in the a-C films (deposited on PTFE substrates) increase from 74% to 93% as nitrogen doping increases, with a step-like increase in sp2 fraction when nitrogen concentrations in the films exceed 27%. The a-C films on silicon substrates display the same trend of increasing sp2 concentration as a function of greater nitrogen concentration. Nanodiamond deposition conditions, such as bias voltage and methane concentration, affect the purity of the film. Our analysis reveals sp2 bonding concentrations in these samples ranging from a few percent to 11%.PACS Nos.: 78.70.Dm, 61.10.Ht, 61.46.+w, 81.05.Uw

scholarly journals Effect of nitrogen on physical and optical properties of carbon films prepared by microwave plasma CVD for photovoltaic solar cells

2012 ◽  
Vol 10 (10) ◽  
pp. 77-79
Author(s):  
Sunil Adhikary
Keyword(s):  
Amorphous Carbon ◽  
Vapour Deposition ◽  
Microwave Plasma ◽  
Chemical Vapour ◽  
Carbon Films ◽  
Scientific World ◽  
Microwave Plasma Cvd ◽  
Plasma Chemical Vapour Deposition ◽  
Photovoltaic Solar Cells ◽  
Quartz Substrates

Nitrogen doped amorphous carbon thin films were deposited on silicon and quartz substrates by microwave surface-wave plasma chemical vapour deposition (MW SWP CVD) to investigate effect of nitrogen on properties of the carbon films. Deposition rate of the films found in the range of 5-7.5 nm/min. Optical band gap of the films decreased from 3.3 eV to 2.3 eV corresponding to the increase of nitrogen flow rates from 0 to 10 sccm. RMS roughness of the undoped and Ndoped films was found to be 0.5 nm and 0.55 nm respectively suggesting that the amorphous carbon films deposited by MW SWP CVD are smooth. Scientific World, Vol. 10, No. 10, July 2012 p77-79 DOI: http://dx.doi.org/10.3126/sw.v10i10.6867

Reduced interface state densities for remote microwave plasma silicon nitride

1992 ◽  
Vol 70 (10-11) ◽  
pp. 795-798 ◽  
Author(s):  
D. Landheer ◽  
J. A. Bardwell ◽  
I. Sproule ◽  
J. Scott-Thomas ◽  
W. Kwok ◽  
...  
Keyword(s):  
Microwave Plasma ◽  
Field Effect Transistors ◽  
Chemical Vapour ◽  
Depth Profiling ◽  
Interface State ◽  
State Density ◽  
Fixed Charge ◽  
Silicon Substrates ◽  
Plasma Chemical Vapour Deposition ◽  
State Densities

The interface state density and fixed charge density of films of a-Si3N4:H deposited on silicon substrates by remote microwave plasma chemical vapour deposition have been studied as a function of deposition and annealing temperature. Interface state densities (Dit as low as 9 × 1010 cm−2 eV−1 have been obtained for films deposited at 215 °C and annealed for 15 min at 500 °C. The films exhibited positive fixed charge levels (QN/q)> 1013 cm−2, increasing slightly with deposition temperature and decreasing slightly with annealing at temperatures from 500 to 700 °C. Fourier transform infrared spectroscopy and Auger depth profiling were used to study the impurities in the films and at the interface. Metal–insulator–silicon field effect transistors made with these films showed room temperature effective channel hole mobilities of 37 cm2 V−1 s−1.

scholarly journals Hydrogen quantification in hydrogenated amorphous carbon films by infrared, Raman, and x-ray absorption near edge spectroscopies

2009 ◽  
Vol 105 (9) ◽  
pp. 093510 ◽  
Author(s):  
J. G. Buijnsters ◽  
R. Gago ◽  
I. Jiménez ◽  
M. Camero ◽  
F. Agulló-Rueda ◽  
...  
Keyword(s):  
Amorphous Carbon ◽  
Carbon Films ◽  
Amorphous Carbon Films ◽  
X Ray ◽  
Hydrogenated Amorphous Carbon ◽  
X Ray Absorption ◽  
Hydrogenated Amorphous

Selective Growth of Diamond Films On Mirror-Polished Silicon Substrates

1993 ◽  
Vol 334 ◽  
Author(s):  
M.Y. Mao ◽  
S.S. Tan ◽  
X.K. Zhang ◽  
W.Y. Wang
Keyword(s):  
Vapour Deposition ◽  
Microwave Plasma ◽  
Chemical Vapour ◽  
Polycrystalline Diamond ◽  
Nucleation Density ◽  
Silicon Substrates ◽  
Plasma Chemical ◽  
Diamond Nucleation ◽  
Plasma Chemical Vapour Deposition ◽  
Surface Particle

AbstractPolycrystalline diamond thin films have been selectively grown on mirror-polished silicon substrates using bias-enhanced microwave plasma chemical vapour deposition (MPCVD) to increase diamond nucleation density. A slight etching of Si02 mask was employed after the nucleation treatment to remove the diamond nuclei on the mask. Perfect diamond patterns with smooth surface (particle size <0.5µm) and sharp boundaries were obtained. The diamond film gears with 400µm in diameter and 5µm in thickness were first fabricated by this technique.

Ultrananocrystalline Diamond / Amorphous Carbon Composite Films – Deposition, Characterization and Applications

2010 ◽  
Vol 159 ◽  
pp. 49-55
Author(s):  
Cyril Popov ◽  
Wilhelm Kulisch ◽  
Christo Petkov ◽  
Johann Peter Reithmaier
Keyword(s):  
Amorphous Carbon ◽  
Vapour Deposition ◽  
Microwave Plasma ◽  
Composite Films ◽  
Chemical Vapour ◽  
Polycrystalline Diamond ◽  
Carbon Composite ◽  
Bonding Structure ◽  
Ultrananocrystalline Diamond ◽  
Plasma Chemical Vapour Deposition

UNCD/a-C composite films have been deposited by microwave plasma chemical vapour deposition from methane/nitrogen mixtures with 17% CH4 in the temperature range 500-770°C on various substrates such as monocrystalline silicon wafers, polycrystalline diamond, c-BN, TiN, GaAs, and other materials of technological interest. The resulting films have been thoroughly characterized with respect to their morphology, crystallinity, composition, and bonding structure. It was found that they are composed of diamond nanocrystallites (3-5 nm in diameter) surrounded by 1-1.5 nm amorphous carbon grain boundary material; the ratio of the volume fractions of crystalline and amorphous phase is close to unity. The investigations of the application-relevant properties of the UNCD/a-C films revealed that they are attractive for a number of mechanical, tribological, structural, and biomedical applications.

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