Excimer Laser Induced Modification of Teflon Surface into Silicon Carbide-Like

1991 ◽  
Vol 236 ◽  
Author(s):  
M. Okoshi ◽  
K. Toyoda ◽  
M. Murahara
Keyword(s):  
Silicon Carbide ◽  
Excimer Laser ◽  
Photochemical Reaction ◽  
Surface Region ◽  
Mixed Gas ◽  
Near Surface ◽  
Modification Process ◽  
Gas Atmosphere ◽  
Ft Ir ◽  
Arf Excimer Laser

AbstractA silicon carbide-like layer was produced in the near-surface region of teflon by irradiating with an ArF excimer laser in a SiH4 and B(CH3)3 mixed gas atmosphere. The pure photochemical reaction was employed in the modification process, and the defluorination of the surface was performed with boron atoms which were photodissociated from B(CH3)3. The CH3 radicals, also photodissociated, induced the dehydrogenation of SiH4 gas; which followed the production of SiHx radicals. The SiHx radicals and CH3 radicals which could not have induced the dehydrogenation of SiH4 were substituted for fluorine atoms of the surface. As a result, the surface was photomodified into silicon carbide. Chemical composition of the photomodified surface was inspected by the XPS and the ATR-FT-IR spectra measurement, and the bonding of the Si-CH3 radicals which traded off the reduction of the fluorine atoms was comfirmed. The Si/C composition ratio of the photomodified surface was 0.7.

Photochemical Modification of Fluorocarbon Resin Surface to Adhere with Epoxy Resin

1993 ◽  
Vol 334 ◽  
Author(s):  
M. Okoshi ◽  
T. Miyokawa ◽  
H. Kashiura ◽  
M. Murahara
Keyword(s):  
Tensile Test ◽  
Adhesive Strength ◽  
Photochemical Reaction ◽  
Water Solution ◽  
Surface Region ◽  
Oh Radicals ◽  
Near Surface ◽  
Modification Process ◽  
Arf Excimer Laser ◽  
Photochemical Modification

AbstractAn epoxy-compatible layer was produced in the near-surface region of a fluorocarbon resin by irradiating with an ArF excimer laser in a gaseous B(CH3)3 or a B(OH)3 water solution atmosphere. The pure photochemical reaction was employed in the modification process, the defluorination of the surface was performed with boron atoms which were photo-dissociated from B(CH3)3 or B(OH)3. The CH3 or OH radicals, also photo-dissociated, replaced the fluorine atoms of the surface. As a result, chemical bonding of the surface with the epoxy was performed. The adhesive strength was evaluated by the shearing tensile test, and the epoxy break value of 130 kgf/cm2 was sucessfully achieved.

Ablation effects and mechanism of sintered silicon carbide ceramics by an ArF excimer laser

2018 ◽  
Vol 16 (9) ◽  
pp. 091402
Author(s):  
Xin Guo Xin Guo ◽  
Jinbin Ding Jinbin Ding ◽  
Yi Zhou Yi Zhou ◽  
Yu Wang Yu Wang
Keyword(s):  
Silicon Carbide ◽  
Excimer Laser ◽  
Arf Excimer Laser ◽  
Carbide Ceramics ◽  
Silicon Carbide Ceramics ◽  
Sintered Silicon

Time-Resolved Reflectivity Measurements of Silicon And Germanium Using A Pulsed Excimer Laser

1985 ◽  
Vol 51 ◽  
Author(s):  
G. E. Jellison ◽  
D. H. Lowndes ◽  
D. N. Mashburn ◽  
R. F. Wood
Keyword(s):  
Excimer Laser ◽  
Surface Region ◽  
Finite Energy ◽  
Time Resolved ◽  
Model Calculations ◽  
Near Surface ◽  
Maximum Reflectivity ◽  
Liquid Phases ◽  
Silicon And Germanium ◽  
Melt Duration

ABSTRACTTime-resolved reflectivity measurements of silicon and germanium have been made during pulsed KrF excimer laser irradiation. The reflectivity was measured simultaneously at both 1152 and 632.8 nm wavelengths, and the energy density of each laser pulse was monitored. The melt duration and the time of the onset of melting were measured and compared with the results of melting model calculations. For energy densities just above the melting threshold, it was found that the melt duration was never less than 20 ns for Si and 25 ns for Ge, while the maximum reflectivity increased from the value of the hot solid to that of the liquid over a finite energy range. These results, along with a reinterpretation of earlier time-resolved ellipsometry measurements, indicate that, during the melt-in process, the near-surface region does not melt homogeneously, but rather consists of a mixture of solid and liquid phases. The reflectivity at the onset of melting and in the liquid phase have been measured at both 632.8 and 1152 nm, and are compared with the results found in the literature.

Growth of Silicon Films Onto Fluororesin Surface by ArF Excimer Laser

1993 ◽  
Vol 334 ◽  
Author(s):  
T. Miyokawa ◽  
M. Okoshi ◽  
K. Toyoda ◽  
M. Murahara
Keyword(s):  
Surface Roughness ◽  
Surface Modification ◽  
Excimer Laser ◽  
High Density ◽  
Silicon Films ◽  
Chemical Compositions ◽  
Xps Analysis ◽  
Modification Process ◽  
Arf Excimer Laser ◽  
Mixed Gases

AbstractSilicon films were deposited on a fluororesin surface. The process was divided into two steps: surface modification process and silicon CVD onto the modified parts. In the modification process, SiH4 and B(CH3)3 mixed gases were used with ArF excimer laser. Fluorine atoms of the surface were pulled out by boron atoms which were photo—dissociated from B(CH3)3 and were replaced with silicon atoms released from SiH4. In the CVD process, SiH4 gas was used with high—density excited ArF excimer laser. Silicon films were deposited onto the nuclei by photodecomposition of SiH4.Chemical compositions of the modified layers and the deposited parts were inspected by XPS analysis. 1000 Å thickness of the deposited silicon films was confirmed by the surface roughness interference–meter.

Solid state interfacial reactions of Ti3Al with Si3N4 and SiC

1992 ◽  
Vol 7 (5) ◽  
pp. 1253-1265 ◽  
Author(s):  
T.C. Chou ◽  
A. Joshi
Keyword(s):  
Silicon Carbide ◽  
Solid State ◽  
Surface Region ◽  
Interfacial Reactions ◽  
Titanium Silicide ◽  
Reaction Products ◽  
Near Surface ◽  
Titanium Silicon Carbide ◽  
Titanium Silicon Nitride ◽  
Titanium Silicon

Solid state interfacial reactions of Ti3Al with Si3N4 and SiC have been studied via both bulk and thin film diffusion couples at temperatures of 1000 and 1200 °C. The nature of reactions of Ti3Al with Si3N4 and SiC was found to be similar. Only limited reactions were detected in samples reacted at 1000 °C. In the Ti3Al/Si3N4, layered reaction products consisting of mainly titanium silicide(s), titanium-silicon-aluminide, and titanium-silicon-nitride were formed; in the Ti3Al/SiC, the reaction product was primarily titanium-silicon-carbide. In both cases, silicon was enriched near the surface region, and aluminum was depleted from the reacted region. Reactions at 1200 °C resulted in a drastic change of the Si distribution profiles; the enrichment of Si in near surface regions was no longer observed, and the depletion of Al became more extensive. Titanium nitride and titanium-silicon-carbide were the major reaction products in the Ti3Al/Si3N4 and Ti3Al/SiC reactions, respectively. Mechanisms of driving the variation of Si, N, and C diffusion behavior (as a function of temperature) and the depletion of Al from the diffusion zone are suggested. It is proposed that reactions of Ti3Al with Si3N4 and SiC lead to in situ formation of a diffusion barrier, which limits the diffusion kinetics and further reaction. The thermodynamic driving force for the Ti3Al/Si3N4 reactions is discussed on the basis of Gibbs free energy.

Low Temperature Crystallization of Amorphous Silicon Films Using an Excimer Laser

1989 ◽  
Vol 149 ◽  
Author(s):  
S. E. Ready ◽  
J. B. Boyce ◽  
R. Z. Bachrach ◽  
R. I. Johnson ◽  
K. Winer ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Excimer Laser ◽  
Laser Energy ◽  
Amorphous Material ◽  
Surface Region ◽  
Silicon Films ◽  
Starting Material ◽  
Near Surface ◽  
Silicon Thin Films ◽  
Crystallite Sizes

ABSTRACTIn an effort to enhance the electrical properties of silicon thin films, we have performed recrystallization experiments on a variety of amorphous silicon films using an excimer laser. The intense, pulsed UV produced by the laser (308nm, using XeCl gas) is highly absorbed by the amorphous material and thus provides intense localized heating in the near surface region. Two types of starting films were studied: plasma CVD a-Si:H and LPCVD a-Si. The subsequent modification produces crystallites whose structure and electrical characteristics vary due to starting material and laser scan parameters. The treated films have been characterized using Raman, x-ray diffraction, TEM, SIMS and transport measurements. The results indicate that crystallites nucleate in the surface region. The degree of crystallization near the surface increases dramatically as a function of deposited laser energy density and less so as a function of laser shot density. The hall mobility of the highly crystallized samples exhibit an increase of 2 orders of magnitude over the amorphous starting material. In the PECVD material, the rapid diffusion of hydrogen causes voids to be formed at intermediate laser energy densities and removal of film at higher energy densities. The LPCVD material withstands the high laser energies to produce well crystallized films with crystallite sizes greater then 1000Å.

Precipitation of carbon in zeolites using photochemical reaction excited by an ArF excimer laser

1998 ◽  
Author(s):  
Yuka Yamada ◽  
Shigeru Takeyama ◽  
Takaaki Orii ◽  
Takehito Yoshida
Keyword(s):  
Excimer Laser ◽  
Photochemical Reaction ◽  
Arf Excimer Laser

Carbon Film Synthesis on the Water by Excimer Laser Irradiation

1998 ◽  
Vol 555 ◽  
Author(s):  
H. Hidai ◽  
H. Tokura
Keyword(s):  
Raman Spectrum ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Carbon Film ◽  
Carbon Films ◽  
Elementary Analysis ◽  
Excimer Laser Irradiation ◽  
Ft Ir ◽  
Arf Excimer Laser ◽  
Film Synthesis

AbstractWater was used as a substrate and carbon films were obtained from methane gas on the water by ArF excimer laser. The film was analyzed by a SEM, elementary analysis, Raman spectrum and FT-IR. Moreover synthesized position of the film was studied.

scholarly journals Laser Mixing of Titanium on Silicon Carbide

1989 ◽  
Vol 157 ◽  
Author(s):  
T. R. Jervis ◽  
J-P. Hirvonen ◽  
M. Nastasi ◽  
M. R. Cohen
Keyword(s):  
Silicon Carbide ◽  
Excimer Laser ◽  
Laser Processing ◽  
Surface Region ◽  
Substrate Material ◽  
Laser Surface ◽  
X Ray Diffraction ◽  
Mixing Conditions ◽  
Surface Processing ◽  
X Ray

ABSTRACTWe have used excimer laser surface processing to melt and mix single Ti layers into the surface of polycrystalline SiC substrates. The mixing of Ti into the surface is very rapid and efficient. Examination of Rutherford backscattering (RBS) data for different mixing conditions shows the formation of a preferred composition at the Ti-substrate interface which propagates from the interface with further mixing. Reconstruction of the RBS spectrum indicates that the composition of the layer is Ti45C37Si18. X-ray diffraction demonstrates the formation of Ti suicides and carbides in the surface region. Profiling of C in both mixed and uncoated samples by 6 MeV He+ scattering demonstrates that laser processing of the SiC does not cause major changes in the stoichiometry of the substrate material.

High Selective Etching of SiO2/Si by ArF Excimer Laser

1993 ◽  
Vol 334 ◽  
Author(s):  
K. Kitamura ◽  
M. Murahara
Keyword(s):  
Laser Beam ◽  
Excimer Laser ◽  
Wavelength Region ◽  
Chemical Behavior ◽  
Mixed Gas ◽  
Reaction Cell ◽  
Si Substrates ◽  
Excimer Laser Irradiation ◽  
Arf Excimer Laser ◽  
Uv Absorption Spectrum

AbstractDry etching of SiO2 insulation layer has been required in the Si semiconductor manufacturing process. The etching of SiO2/Si is chemically carried out by using HF solution. We successfully demonstrated a new method for exclusive etching of SiO2 using the nitrosyle fluoride (NFO) gas which was produced from the mixed gas of NF3 and O2 with an ArF excimer laser irradiation.SiO2 and Si substrates were placed side by side in a reaction cell which was filled with 3% O2 gas in NF3 at the gas pressure of 380 Torr. ArF excimer laser beam was irradiated parallel to the substrates. The laser fluence was kept at lOOmJ/cm2. As soon as the mixed gas of NF3 and O2 was irradiated with the ArF laser beam, an intermediate product of NFO was produced. The chemical behavior of NFO was confirmed from the UV absorption spectrum with absorption in the 310 to 330nm wavelength region. In the presence of SiO2, the absorption of NFO diminished. The absorption of NO2, instead of NFO, appeared at 350nm. This indicates that the oxygen atoms of SiO2 were pulled out by NFO.The etching reactions continued for 3 minutes after irradiation when the SiO2 and Si substrates were kept in an atmosphere of the reactant gases. As a result, not the Si but SiO2 substrate was etched with the depth of 2000Å.

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