Excimer Laser Direct Write Aluminum on Aluminum Nitride

1995 ◽  
Vol 390 ◽  
Author(s):  
Hua Li ◽  
Janet K. Lumpp
Keyword(s):  
Aluminum Nitride ◽  
Excimer Laser ◽  
Laser Energy ◽  
Laser Exposure ◽  
Direct Write ◽  
Electron Microscopies ◽  
Scan Speed ◽  
Krf Excimer Laser ◽  
Induced Decomposition ◽  
Made In

ABSTRACTFabrication of metal lines on aluminum nitride (AIN) ceramic is important for application of AIN as a microcircuit board. An Al line can be made directly from AIN by excimer laser exposure. All lines in this paper were written by pulsed KrF excimer laser (248 nm) in air and vacuum at different scan speeds with a constant laser energy. The morphology of the Al lines was observed by optical and scanning electron microscopies. The lines become more metallic when the scan speed decreases. Consequently the resistance, measured by the four-point probe technique, decreased to a minimum value in the scan speed range of 400 μm/s to 900 μm/s for the samples made in air. The resistance of Al lines written in air is greater than that in vacuum because of oxidation. The samples made in air with scan speed lower than 400 μm/s were heavily oxidized. SAXPS spectra showed a strong oxidation state and that the excimer laser exposure depletes nitrogen from AMN. The Al lines produced by laser-induced decomposition of AMN board are being evaluated as catalysts for laser assisted CVD and conventional electroless plating. The oxidation layer on the surface of Al lines may effect the adhesion between the Al lines and the deposited or plated metal.

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.

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.

Recent Progress in Excimer Laser Lithography

1987 ◽  
Vol 101 ◽  
Author(s):  
I. Higashikawa ◽  
M. Nonaka ◽  
T. Sato ◽  
M. Nakase ◽  
S. Ito ◽  
...  
Keyword(s):  
Excimer Laser ◽  
Diffraction Method ◽  
Pulse Frequency ◽  
Field Size ◽  
Laser Exposure ◽  
Projection Lens ◽  
Laser Lithography ◽  
Alignment System ◽  
Space Pattern ◽  
Krf Excimer Laser

ABSTRACTA KrF excimer laser exposure method has been developed for laboratory use, which employs 10 to 1 achromatic projection lens of 0.37 NA and 5x5 mm field size , and a TTL alignment system using the double diffraction method, which was realized by the use,of the achromatic lens. Novolak type mid-UV resists, such as AZ-5214 and PR-1024, were best suited for use in 248 nm exposure, considering the sensitivity and etching resistance from a practical viewpoint, and an additional post exposure baking process also improved the resist profile. The dependences of the exposure characteristics on the energy density per pulse and pulse frequency of these resists were not observed in the region of the practical exposure conditions. An alignment precision of x±30-= 0.2 μm was achieved for the alignment mark consisting of poly Si pattern. Thus, a 0.3 μm line and space pattern was realized by using tri-level resist process and a 0.2 μm gate pattern was successfully fabricated on the coplanar pattern with a 0.4 μm step.

Excimer Laser-Induced Decomposition of Aluminum Nitride

1991 ◽  
Vol 236 ◽  
Author(s):  
H. Esrom ◽  
J-Y Zhang ◽  
A.J. Pedraza
Keyword(s):  
Aluminum Nitride ◽  
Excimer Laser ◽  
Photoelectron Spectroscopy ◽  
Laser Energy ◽  
Liquid Aluminum ◽  
Aluminum Film ◽  
Hole Drilling ◽  
Addition Line ◽  
Substrate Roughness ◽  
Direct Laser

AbstractA thin film of aluminum, detected by x-ray photoelectron spectroscopy, is left at the surface of aluminum nitride (AIN) substrates exposed to a high intensity excimer laser beam of UV radiation. Due to the presence of this film, there is a decrease in the surface resistivity of the substrate with increasing number of laser pulses. In addition, line profilometry shows a decrease of the surface roughness with the number of pulses.The thermal decomposition of AIN is assumed to take place in two stages. In the first, liquid aluminum is produced together with the evolution of gaseous nitrogen, and in the second, aluminum evaporates. Using a computer model to simulate the laser heating cycle, it is shown that the thickness of the aluminum film saturates at a given laser energy density. The saturation thickness is a strong function of the substrate absorption and reflectivity and, therefore, of the laser light frequency. The influence of the substrate roughness on the electrical resistivity of the aluminum film is discussed.The application of this process to direct laser writing in high density hybrid circuits is illustrated. During hole drilling by excimer laser, a thin aluminum film is continuously produced at the hole walls. This process can also be employed for substrate planarization.

Deposition of aluminum nitride thin film on Si(111) by KrF excimer laser and its characterizations

2008 ◽  
Vol 254 (8) ◽  
pp. 2211-2215 ◽  
Author(s):  
Ming Chang Shih ◽  
Chi Wei Liang ◽  
Ping Ju Chaing
Keyword(s):  
Thin Film ◽  
Aluminum Nitride ◽  
Excimer Laser ◽  
Krf Excimer Laser

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

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3671
Author(s):  
Umm-i-Kalsoom Umm-i-Kalsoom ◽  
Nisar Ali ◽  
Shazia Bashir ◽  
Ali Mohammad Alshehri ◽  
Narjis Begum
Keyword(s):  
Chemical Composition ◽  
Excimer Laser ◽  
Surface Engineering ◽  
Laser Energy ◽  
Chemical Reactivity ◽  
Aerospace Industry ◽  
Central Wavelength ◽  
X Ray ◽  
Laser Fluences ◽  
Krf Excimer Laser

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.

Realization of practical attenuated phase-shift mask with high-transmission KrF excimer laser exposure

1999 ◽  
Author(s):  
Nobuhito Toyama ◽  
Hiroyuki Miyashita ◽  
Yasutaka Morikawa ◽  
Hiroshi Fujita ◽  
Kazuya Iwase ◽  
...  
Keyword(s):  
Phase Shift ◽  
Excimer Laser ◽  
Laser Exposure ◽  
High Transmission ◽  
Krf Excimer Laser ◽  
Phase Shift Mask

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.

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.

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