scholarly journals Orderly Perforation of Polyester Films by Excimer Laser

2015 ◽  
Author(s):  
Wenqi Li ◽  
Erol Sancaktar
Keyword(s):  
Excimer Laser ◽  
Laser Energy ◽  
Laser Pulses ◽  
High Laser Fluence ◽  
High Laser ◽  
Area Increase ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser ◽  
Different Thickness ◽  
Pet Films

The effects of 248 nm KrF excimer laser irradiation on combinations of different thickness PET films and different stainless steel mask mesh opening sizes were considered as a possible method to achieve different size perforations on different thickness PET films, in order to provide an effective and controllable perforation technology. Therefore, ablation behavior of PET films has been investigated for different laser energy fluence and number of laser pulses. Morphology of irradiated samples was observed by optical microscopy, and atomic forced microscopy to study topography and microstructures after laser ablation. An attempt has been made of correlate these findings with the orientation, strength and mechanical properties of the polymer. The experimental results reveal that the percentage of perforation and the average perforated area increase with increasing number of pulses for all film thicknesses. The affected area, defined as the perforated area plus the heat affected zone (a black-char-region around the perforated area) decrease with increasing number of pulses. Due to the heat conducted from the steel mash wire, especially at cell corners, the perforation process seems to start initially at the cell corners. High laser fluence seems to lead to surface depressions due to thermal shock and surface stress waves along the process directions confirmed by tensile testing and x-ray analyses. The presence and the geometry of surface depressions were confirmed by atomic forced microscopy.

Poly-Resistor Thin Film Formation by Excimer Laser Micromachine

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.

scholarly journals Improving Optical and Electrical Properties of GaN Epitaxial Wafers and Enhancing Luminescent Properties of GaN-Based Light-Emitting-Diode with Excimer Laser Irradiation

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1935
Author(s):  
Yijian Jiang ◽  
Haoqi Tan ◽  
Yan Zhao
Keyword(s):  
Electrical Properties ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Laser Energy ◽  
Hole Concentration ◽  
Light Output ◽  
Annealing Treatment ◽  
Optical And Electrical Properties ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser

The effect of KrF excimer laser irradiation on the optical and electrical properties of epitaxial wafers with a p-GaN surface were investigated at different laser energy densities and pulse numbers. The laser-irradiated samples were annealed in oxygen. The laser irradiation-induced changes in optical and electrical properties of GaN epitaxial wafers were examined using PL, I–V, XPS, SIMS, and Hall effect measurements. Experimental results show that under an appropriate laser-irradiated condition, optical and electrical properties of the samples were improved to different degrees. The samples which were annealed after laser irradiation have better electrical properties such as the hole concentration and sheet resistance than those without annealing. We hypothesize that the pulsed KrF excimer laser irradiation dissociates the Mg–H complexes and annealing treatment allows the hydrogen to diffuse out more completely under the oxygen atmosphere at a proper temperature, by which the crystalline symmetry of GaN is improved. Under appropriate laser conditions and O2-activated annealing, the light output of the laser-irradiated GaN-based LED sample is about 1.44 times that of a conventional LED at 20 mA. It is found that the wall-plug efficiency is 10% higher at 20 mA and the reverse leakage current is 80% lower at 5 V.

Influence of Environment on Excimer Laser Irradiation of Metals

1986 ◽  
Vol 74 ◽  
Author(s):  
Julian P. Partridge ◽  
Joseph Pellegrino ◽  
Craig Murphy ◽  
Peter R. Strutt
Keyword(s):  
Excimer Laser ◽  
Dense Plasma ◽  
Laser Pulses ◽  
Plasma Pressure ◽  
Pressure Fields ◽  
Wave Patterns ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser ◽  
Rapidly Solidified ◽  
Good Agreement

AbstractIrradiation of metals in gaseous and liquid nitrogen by KrF excimer laser pulses shows the way in which vapor or plasma pressure fields determine the nature of the rapidly solidified surface topography. Wave patterns formed on aluminum by irradiation in N2 gas arise from recoil pressure differences produced by highly localised differential surface evaporation. The solidification time, calculated from the observed ripple wavelength, is in good agreement with that deduced from a heat flow calculation. For irradiation in liquid N2, the homogeneous pressure within the center of the dense plasma zone results in a smooth surface. Beyond this region the progressively diminishing pressure induces surface ripples, fragmentation and droplet formation. Intriguingly, immersion of Ni, Ti, Zn, and Al in liquid N2 (to a depth of 2 to 4 mm) considerably increases the area and depth of irradiation-modified regions.

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

1990 ◽  
Vol 5 (2) ◽  
pp. 265-270 ◽  
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).

Computer Simulation of Pulsed Laser Ablation for YBaCuO Superconducting Films

1990 ◽  
Vol 191 ◽  
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.

Etch Performance of KRF Excimer Laser Micromachining Characterization on Silicon Material

2015 ◽  
Vol 780 ◽  
pp. 29-32 ◽  
Author(s):  
M.Z. Zainol ◽  
Yufridin Wahab ◽  
H. Fazmir ◽  
A.F.M. Anuar ◽  
S. Johari ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Etch Rate ◽  
Three Dimensional ◽  
Laser Pulses ◽  
Laser Micromachining ◽  
Rate Change ◽  
Performance Parameters ◽  
Laser Parameters ◽  
Characterization Study ◽  
Krf Excimer Laser

Excimer laser micromachining enables us to overcome the conventional lithography-based microfabrication limitations and simplify the process of creating three dimensional (3D) microstructures.The objective of this study is to investigate the relation between the number of laser pulses, number of laser passes through the channel of ablation site and their etch performance. Parameters such as frequency, fluence and velocity were retained as constants. In this paper, we present a parametric characterization study on silicon using KrF excimer laser micromachining. From the result, the etch rate change were recorded as the two major laser parameters (Number of laser pulses and number of laser passes) were varied. Both parameters were showing declination profile however from comparing both graphs, it showed that etch rate dropped more steeply when varied number of laser passes rather than number of pulses.

scholarly journals Formation of Varistor Layer at the Surface of SrTiO3-Based Ceramics by KrF Excimer Laser Irradiation.

1999 ◽  
Vol 107 (1252) ◽  
pp. 1229-1231 ◽  
Author(s):  
Jong-Won YOON ◽  
Katsuki HIGAKI ◽  
Masaru MIYAYAMA ◽  
Tetsuichi KUDO
Keyword(s):  
Laser Irradiation ◽  
Excimer Laser ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser
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