Studies of Carbon Nitride Thin Films Synthesized by KrF Excimer Ablation of Graphite in Nitrogen Atmosphere

1998 ◽  
Vol 526 ◽  
Author(s):  
Z.M. Ren ◽  
Y.F. Lu ◽  
W.D. Song ◽  
D.S.H. Chan ◽  
T.S. Low ◽  
...  
Keyword(s):  
Thin Films ◽  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Nitrogen Pressure ◽  
Laser Wavelength ◽  
Nitrogen Atmosphere ◽  
Amorphous Semiconductor ◽  
X Ray ◽  
Krf Excimer Laser

AbstractCarbon nitride thin films were deposited on silicon wafers by pulsed KrF excimer laser (wavelength 248 nm, duration 23 ns) ablation of graphite in nitrogen atmosphere. Different fluences of the excimer laser and pressures of the nitrogen atmosphere were used in order to achieve a high nitrogen content in the deposited thin films. Fourier Transform Infra-red (FTIR) and X-ray photoelectron spectroscopy (XPS) were used to identify the binding structure and the content of the nitrogen species in the deposited thin films. The highest N/C ratio 0.42 was achieved at an excimer laser fluence of 0.8 Jcm -2with a repetition rate of 10 Hz under the nitrogen pressure of PN=100 mTorr. A high content of C=N double bond instead of C-N triple bond was indicated in the deposited thin films. Ellipsometry was used to analyze the optical properties of the deposited thin films. The carbon nitride thin films have amorphous-semiconductor-like characteristics with the optical band gap Eop, as high as 0.42 eV.

Studies of carbon nitride thin films synthesized by KrF excimer laser ablation of graphite in a nitrogen atmosphere

1998 ◽  
Vol 84 (5) ◽  
pp. 2909-2912 ◽  
Author(s):  
Y. F. Lu ◽  
Z. M. Ren ◽  
W. D. Song ◽  
D. S. H. Chan ◽  
T. S. Low ◽  
...  
Keyword(s):  
Thin Films ◽  
Laser Ablation ◽  
Excimer Laser ◽  
Carbon Nitride ◽  
Nitrogen Atmosphere ◽  
Excimer Laser Ablation ◽  
Krf Excimer Laser

Effect of Gaseous Medium Pressure on Plasmadynamic Synthesis Product in the C-N System with Melamine

2014 ◽  
Vol 1040 ◽  
pp. 813-818 ◽  
Author(s):  
I.I. Shanenkov ◽  
Artur A. Sivkov ◽  
А.Ya. Pak ◽  
Yu.L. Kolganova
Keyword(s):  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Gaseous Medium ◽  
Morphological Changes ◽  
Nitrogen Pressure ◽  
Synthesis Product ◽  
X Ray Diffraction ◽  
Capacitive Energy Storage ◽  
X Ray ◽  
Transmission Electron

The possibility of plasmodynamic synthesis in the carbon-nitrogen system when using melamine as a precursor is described in the paper. The system based on the capacitive energy storage, which allows simultaneously powering the two opposite-directed coaxial magnetoplasma accelerators, is developed. The effect of gaseous medium in the processing chamber of the system on the synthesis product is investigated by applying such techniques as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). It is demonstrated that an increase in nitrogen pressure results in the structural and morphological changes in the synthesized sample, which might be caused by the increased carbon nitride yield and a great number of the appearing C-N bonds.

Laser Induced Decomposition of Triethylgallium and Trimethylgallium Adsorbed on GaAs(100)

1988 ◽  
Vol 129 ◽  
Author(s):  
J. A. Mccaulley ◽  
V. R. Mccrary ◽  
V. M. Donnelly
Keyword(s):  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Electronic Excitation ◽  
Removal Rate ◽  
Laser Wavelength ◽  
High Fluence ◽  
X Ray ◽  
Two Photon ◽  
Induced Decomposition

ABSTRACTWe report X-ray photoelectron spectroscopy (XPS) studies of excimer laser stimulated decomposition of triethylgallium (TEGa) and trimethylgallium (TMGa) adsorbed on Gastabilized GaAs(100) surfaces in ultrahigh vacuum. TEGa and TMGa dissociatively chemisorb on GaAs at room temperature, whereupon irradiation by an excimer laser (at 193 or 351 nm) leads to further dissociation and desorption of carbon-containing species. The carbon removal rate (per laser pulse) decreases as carbon is removed suggesting multiple reaction sites, coverage dependent Arrhenius parameters, or second-order reactions. Based on the dependence of the rate on laser wavelength and fluence, we conclude that at low fluence, a two-photon electronic excitation of the adsorbate occurs, while at high fluence, laser induced pyrolysis dominates.

Effects of Irradiation by Low Energy Nitrogen Ions on Carbon Nitride Thin Films

2002 ◽  
Vol 750 ◽  
Author(s):  
Yuka Nasu ◽  
Masami Aono ◽  
Shinichiro Aizawa ◽  
Nobuaki Kitazawa ◽  
Yoshihisa Watanabe
Keyword(s):  
Thin Films ◽  
Nitrogen Content ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Chemical Vapor ◽  
Low Energy ◽  
Carbon Filament ◽  
X Ray ◽  
Nitrogen Ions

ABSTRACTCarbon nitride (CNx) thin films have been prepared by hot carbon filament chemical vapor deposition, and the nitrogen content in the films is approximately 0.05. The CNx films have been irradiated by 0.1 keV nitrogen ions to increase the nitrogen content after deposition. The nitrogen content in the CNx films was obtained with X-ray photoelectron spectroscopy. Scanning electron microscopy was employed to study microstructures of the films. The experimental results show that nitrogen ions are chemically combined with the CNx films and as a result the nitrogen content increases up to approximately 0.30. Furthermore, it is found that nitrogen ions change the film microstructures and sputter the surfaces of CNx films.

STUDY OF COLORATION ON EXCIMER LASER TREATED TITANIUM SURFACES

2008 ◽  
Vol 15 (05) ◽  
pp. 675-679 ◽  
Author(s):  
H. X. QIAN ◽  
WEI ZHOU ◽  
H. Y. ZHENG
Keyword(s):  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
Morphological Difference ◽  
Surface Oxidation ◽  
Laser Pulses ◽  
Compositional Variation ◽  
X Ray ◽  
Chemical States ◽  
Titanium Surfaces ◽  
Krf Excimer Laser

Surface oxidation of Ti was carried out using KrF excimer laser in the presence of O 2. Different colors were obtained by varying the number of laser pulses at the fixed laser fluence. X-ray photoelectron spectroscopy shows that the outmost surface is composed of TiO 2 and the inner layer consists of TiO and Ti 2 O 3 as well as TiO 2. Fractions of titanium chemical states stabilized at 33% TiO , 63% TiO 2, and 2% Ti 2 O 3 with increasing number of laser pulses. The surface roughness tends to increase with number of laser pulses. It is suggested that compositional variation and morphological difference contribute to the laser-induced surface coloration.

KrF Excimer Laser Ablation of Human Enamel

2008 ◽  
Vol 587-588 ◽  
pp. 42-46 ◽  
Author(s):  
M. Sivakumar ◽  
Vitor Oliveira ◽  
Rui Vilar ◽  
A.M. Botelho do Rego
Keyword(s):  
Laser Treatment ◽  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Structural Water ◽  
X Ray ◽  
Human Enamel ◽  
Excimer Laser Radiation ◽  
Krf Excimer Laser ◽  
Dental Applications

Laser treatment is a promising technique for dental applications such as caries prevention, dental hypersensitivity reduction and improvement of bond strength of restoration materials. In this study the morphological, structural and chemical changes of enamel surface due to treatment with KrF excimer laser radiation were evaluated using scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. For radiation fluences near 1 J/cm², laser processing originates a relatively porous surface due to preferential removal of material in the enamel prism sheaths. Increasing the fluence leads to a relatively flat surface with clear evidence of surface melting. The X-ray diffractograms of both treated and untreated enamel are similar and correspond to hydroxyapatite. The only modification due to the laser treatment is a slight shift of the peaks, probably, due to a loss of the structural water of hydroxyapatite. X-ray photoelectron spectroscopy confirmed that organic matter is removed from the irradiated surface but no significant changes in the mineral phase occur.

Raman and X-ray photoelectron spectroscopy study of carbon nitride thin films

1999 ◽  
Vol 151 (3-4) ◽  
pp. 233-238 ◽  
Author(s):  
P Petrov ◽  
D.B Dimitrov ◽  
D Papadimitriou ◽  
G Beshkov ◽  
V Krastev ◽  
...  
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Carbon Nitride ◽  
Spectroscopy Study ◽  
X Ray

Analysis of X-Ray Photoelectron Spectroscopy of Polymethyl Methacrylate Etched by a KrF Excimer Laser

2005 ◽  
Vol 22 (6) ◽  
pp. 1526-1529 ◽  
Author(s):  
Zhu Xiao-Li ◽  
Liu Shi-Bing ◽  
Chen Tao ◽  
Jiang Yi-Jian ◽  
Zuo Tie-Chuan
Keyword(s):  
Polymethyl Methacrylate ◽  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Krf Excimer Laser
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