Study of Micro/Nano Structuring and Mechanical Properties of KrF Excimer Laser Irradiated Al for Aerospace Industry and Surface Engineering Applications

Micro/nano structuring of KrF Excimer laser-irradiated Aluminum (Al) has been correlated with laser-produced structural and mechanical changes. The effect of non-reactive Argon (Ar) and reactive Oxygen (O2) environments on the surface, structural and mechanical characteristics of nano-second pulsed laser-ablated Aluminum (Al) has been revealed. KrF Excimer laser with pulse duration 20 ns, central wavelength of 248 nm and repetition rate of was utilized for this purpose. Exposure of targets has been carried out for 0.86, 1, 1.13 and 1.27 J.cm−2 laser fluences in non-reactive (Ar) and reactive (O2) ambient environments at a pressure of 100 torr. A variety of characteristics of the irradiated targets like the morphology of the surface, chemical composition, crystallinity and nano hardness were investigated by using Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Diffractometer (XRD), Raman spectroscopy and Nanohardness tester techniques, respectively. The nature (reactive or non-reactive) and pressure of gas played an important role in modification of materials. In this study, a strong correlation is observed between the surface structuring, chemical composition, residual stress variation and the variation in hardness of Al surface after ablation in both ambient (Ar, O2). In the case of reactive environment (O2), the interplay among the deposition of laser energy and species of plasma of ambient gas enhances chemical reactivity, which causes the formation of oxides of aluminum (AlO, Al2O3) with high mechanical strength. That makes it useful in the field of process and aerospace industry as well as in surface engineering.

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Surface hardening of SUS304 by irradiation with a KrF excimer laser in SiH4 gas ambient

Journal of Materials Research ◽

10.1557/jmr.1990.0265 ◽

1990 ◽

Vol 5 (2) ◽

pp. 265-270 ◽

Cited By ~ 4

Author(s):

Koji Sugioka ◽

Hideo Tashiro ◽

Koichi Toyoda ◽

Eiichi Tamura ◽

Keigo Nagasaka

Keyword(s):

Excimer Laser ◽

Surface Hardening ◽

Continuous Distribution ◽

Surface Hardness ◽

Laser Pulses ◽

High Concentration ◽

Laser Fluences ◽

High Adhesion ◽

Krf Excimer Laser ◽

Si Films

Surface hardening of SUS304 resulting from the process of doping and deposition of Si by irradiation of a KrF excimer laser beam in a SiH4 gas ambient is investigated, and variations of the surface hardness are examined for different numbers of laser pulses and the laser fluences. The hardening is due to Si incorporation in high concentration. The continuous distribution of Si atoms across the surface layer suggests that a very high adhesion strength of the deposited Si films can be formed. The specific process for surface modification is referred to as laser implant-deposition (LID).

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

10.1117/12.20605 ◽

1990 ◽

Author(s):

Hakaru Mizoguchi ◽

Akira Endo ◽

Jayden N. Jethwa ◽

Fritz P. Schaefer

Keyword(s):

Excimer Laser ◽

X Ray ◽

Krf Excimer Laser

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Computer Simulation of Pulsed Laser Ablation for YBaCuO Superconducting Films

MRS Proceedings ◽

10.1557/proc-191-109 ◽

1990 ◽

Vol 191 ◽

Cited By ~ 4

Author(s):

Toshiyuki Nakamiya ◽

Kenji Ebihara ◽

P. K. John ◽

B. Y. Tong

Keyword(s):

Thin Films ◽

Excimer Laser ◽

Laser Energy ◽

Pulsed Laser ◽

The Finite Element Method ◽

High Tc ◽

One Dimensional ◽

Incident Laser Energy ◽

Krf Excimer Laser ◽

Pulsed Laser Irradiation

ABSTRACTThe dynamics of melting and ablation of high Tc YBa2Cu3O7-x superconducting thin films flashed by a pulsed KrF excimer laser(λ=248nm) or a pulsed Nd-YAG laser (λ =1.06μ m) were studied numerically. The fundamental model during a pulsed laser irradiation was a one-dimensional heat conduction equation. The finite element method was applied to solve the equation including the temperature dependence of the thermal conductivity of YBaCuO thin films. In addition, the microstructure of YBa2Cu3O7-x bulk(l.5mm thick) flashed by a pulsed XeCl excimer laser (λ =308nm) was investigated by scanning electron microscopy (SEM) in order to estimate the threshold incident laser energy density for surface melting and ablation. The good agreements between the numerical calculations and the experimental results were obtained.

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

Applied Physics Letters ◽

10.1063/1.110253 ◽

1993 ◽

Vol 63 (22) ◽

pp. 3046-3048 ◽

Cited By ~ 15

Author(s):

I. C. E. Turcu ◽

I. N. Ross ◽

G. J. Tallents

Keyword(s):

Excimer Laser ◽

Laser Pulses ◽

X Ray ◽

Krf Excimer Laser

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Poly-Resistor Thin Film Formation by Excimer Laser Micromachine

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.780.17 ◽

2015 ◽

Vol 780 ◽

pp. 17-21

Author(s):

A.F.M. Anuar ◽

Yufridin Wahab ◽

M.Z. Zainol ◽

H. Fazmir ◽

M. Najmi ◽

...

Keyword(s):

Thin Film ◽

Excimer Laser ◽

Laser Energy ◽

Film Formation ◽

Chemical Vapor ◽

Laser Pulses ◽

Beam Size ◽

Silicon Thin Film ◽

Pressure Chemical ◽

Krf Excimer Laser

A simple theoretical model and resistor fabrication for calculating the resistance of a polycrystalline silicon thin film is presented. The resistance value for poly-resistor is perfomed in terms of polysilicon thickness and its total area. The KrF excimer laser micromachine is used in assisting the resistor formation for a low pressure chemical vapor deposition (LPCVD) based polysilicon. Laser micromachine with three main parameters is used to aid the fabrication of the poly-resistor; namely as the pulse rate (i.e. number of laser pulses per second), laser beam size and laser energy. These parameters have been investigated to create the isolation between materials and also to achieve the desired poly-resistor shape. Preliminary results show that the 35 um beam size and 15 mJ of energy level is the most effective parameter to produce the pattern. Poly-resistor formation with 12 and 21 number of squares shows the total average resistance of 303.52 Ω and 210.14 Ω respectively. The laser micromachine process also significantly reduce the total time and number of process steps that are required for resistor fabrication.

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

MRS Proceedings ◽

10.1557/proc-236-429 ◽

1991 ◽

Vol 236 ◽

Cited By ~ 4

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.

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

MRS Proceedings ◽

10.1557/proc-235-843 ◽

1991 ◽

Vol 235 ◽

Cited By ~ 3

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.

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

MRS Proceedings ◽

10.1557/proc-526-343 ◽

1998 ◽

Vol 526 ◽

Cited By ~ 5

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.

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X-ray photoelectron spectroscopic study of KrF excimer laser nitrided InP surface

Journal of Applied Physics ◽

10.1063/1.1412837 ◽

2001 ◽

Vol 90 (12) ◽

pp. 5851-5855 ◽

Cited By ~ 6

Author(s):

Toshimitsu Akane ◽

Koji Sugioka ◽

Katsumi Midorikawa ◽

Jan J. Dubowski ◽

Naoko Aoki ◽

...

Keyword(s):

Spectroscopic Study ◽

Excimer Laser ◽

X Ray ◽

Krf Excimer Laser ◽

Inp Surface

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Effect of Laser Fluence on the Properties of Sm1-XNd X NiO3 Thin Films Deposited by KrF Laser Ablation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.227.72 ◽

2011 ◽

Vol 227 ◽

pp. 72-75

Author(s):

Slimane Lafane ◽

Tahar Kerdja ◽

Samira Abdelli-Messaci ◽

Smail Malek ◽

Malik Maaza

Keyword(s):

Thin Films ◽

Laser Fluence ◽

Room Temperature ◽

Silicon Substrates ◽

X Ray ◽

Substrate Distance ◽

Laser Fluences ◽

Krf Excimer Laser ◽

Rotating Target ◽

Scanning Electron

In this contribution we study the effect of the laser fluence on the stoichiometry, morphology and density of Sm1-xNdxNiO3 thin films. The latter were grown by a KrF excimer laser (λ = 248 nm, τ = 25 ns) ablation of a rotating target onto unheated (100) silicon substrates for 9000 pulses at different laser fluences into vacuum. The target used was a mixture of samarium, neodymium and nickel oxides. The relative ratio of neodymium (x = 0.45) is set to have a transition temperature close to room temperature (TMI = 310 K). The target-substrate distance was maintained at 4 cm. The composition and the morphology of the deposited layers were analysed by energy dispersion X-ray spectroscopy (EDX) and scanning electron microscope (SEM) respectively. It was found that films properties depend strongly on the laser fluence. The EDX measurements revealed that the laser fluence must be higher than 1 Jcm-2 for a congruent evaporation. However, even at this condition, the films were deficiency in oxygen. The morphology study showed that the films surface was widely contaminated by droplets for fluences superior to 2 Jcm-2. Also, it was found that by increasing laser fluence the films density increases and reach a plateau at 1.3 Jcm-2. According to all those elements, the laser fluence was set to be in the range of 1.3 – 2 Jcm-2.

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