Analysis by using X-ray photoelectron spectroscopy for polymethyl methacrylate and polytetrafluoroethylene etched by KrF excimer laser

2007 ◽  
Vol 253 (6) ◽  
pp. 3122-3126 ◽  
Author(s):  
X.L. Zhu ◽  
S.B. Liu ◽  
B.Y. Man ◽  
C.Q. Xie ◽  
D.P. Chen ◽  
...  
Keyword(s):  
Polymethyl Methacrylate ◽  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Krf Excimer Laser

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

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.

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.

10 x 10 cm2 aperture x-ray preionized discharge-pumped KrF excimer laser

1990 ◽  
Author(s):  
Hakaru Mizoguchi ◽  
Akira Endo ◽  
Jayden N. Jethwa ◽  
Fritz P. Schaefer
Keyword(s):  
Excimer Laser ◽  
X Ray ◽  
Krf Excimer Laser

Efficient keV x‐ray emission from plasmas generated with 4 ps KrF excimer laser pulses

1993 ◽  
Vol 63 (22) ◽  
pp. 3046-3048 ◽  
Author(s):  
I. C. E. Turcu ◽  
I. N. Ross ◽  
G. J. Tallents
Keyword(s):  
Excimer Laser ◽  
Laser Pulses ◽  
X Ray ◽  
Krf Excimer Laser

Effects of Processing Parameters on KrF Excimer Laser Ablation Deposited ZrO2 Films

1991 ◽  
Vol 236 ◽  
Author(s):  
Gary A. Smith ◽  
Li-Chyong Chen ◽  
Mei-Chen Chuang
Keyword(s):  
Laser Ablation ◽  
Substrate Temperature ◽  
Excimer Laser ◽  
Deposition Rate ◽  
Oxygen Pressure ◽  
Pressure Dependence ◽  
Laser Fluence ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Krf Excimer Laser

AbstractSystematic experiments have been carried out to characterize the yttria containing zirconia thin films on sapphire substrates by 248nm KrF excimer laser ablation. The deposition rate as a function of laser fluence and O2 pressure at room temperature was measured with a quartz crystal microbalance. The results show different threshold fluences for deposition in vacuum vs. oxygen. While the deposition rate increases with increasing fluence at a given oxygen pressure, the rate eventually saturates at a higher laser fluence. At a given fluence, the oxygen pressure dependence of the deposition rate shows a radical reduction when the O2 pressure increases from 10 mTorr to 1 Torr. Rutherford backscattering spectrometry (RBS) and x-ray photoelectron spectroscopy were used to obtain stoichiometric information. A very strong pressure dependence of the O/Zr ratio was observed. While the trend of increasing O/Zr and Zr/Y ratio with increasing O2 pressure is apparent, the correlations between O/Zr as well as Zr/Y ratio and other processing conditions are less obvious. RBS results indicate an increasing roughness at the interface between the ZrO2 film and the sapphire substrate as the oxygen pressure exceeds 50 mTorr. The structural information obtained from x-ray diffraction patterns indicates broadening of peak width with increasing laser fluence as well as decreasing substrate temperature. For the film deposited at a lower substrate temperature, a strong (002) texture was observed.

Effects of Processing Parameters on KrF Excimer Laser Ablation Deposited ZrO2 Films

1991 ◽  
Vol 235 ◽  
Author(s):  
Gary A. Smith ◽  
Li-Chyong Chen ◽  
Mei-Chen Chuang
Keyword(s):  
Laser Ablation ◽  
Substrate Temperature ◽  
Excimer Laser ◽  
Deposition Rate ◽  
Oxygen Pressure ◽  
Pressure Dependence ◽  
Laser Fluence ◽  
X Ray ◽  
Excimer Laser Ablation ◽  
Krf Excimer Laser

ABSTRACTSystematic experiments have been carried out to characterize the yttria containing zirconia thin films on sapphire substrates by 248nm KrF excimer laser ablation. The deposition rate as a function of laser fluence and O2 pressure at room temperature was measured with a quartz crystal microbalance. The results show different threshold fluences for deposition in vacuum vs. oxygen. While the deposition rate increases with increasing fluence at a given oxygen pressure, the rate eventually saturates at a higher laser fluence. At a given fluence, the oxygen pressure dependence of the deposition rate shows a radical reduction when the O2 pressure increases from 10 mTorr to 1 Torr. Rutherford backscattering spectrometry (RBS) and x-ray photoelectron spectroscopy were used to obtain stoichiometric information. A very strong pressure dependence of the O/Zr ratio was observed. While the trend of increasing O/Zr and Zr/Y ratio with increasing O2 pressure is apparent, the correlations between O/Zr as well as Zr/Y ratio and other processing conditions are less obvious. RBS results indicate an increasing roughness at the interface between the ZrO2 film and the sapphire substrate as the oxygen pressure exceeds 50 mTorr. The structural information obtained from x-ray diffraction patterns indicates broadening of peak width with increasing laser fluence as well as decreasing substrate temperature. For the film deposited at a lower substrate temperature, a strong (002) texture was observed.

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.

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