Computer Modelling of Laser Annealing

1981 ◽  
Vol 4 ◽  
Author(s):  
P. Baeri
Keyword(s):  
Energy Density ◽  
Heat Flow ◽  
Laser Pulse ◽  
Substrate Temperature ◽  
Pulse Duration ◽  
Laser Annealing ◽  
Computer Modelling ◽  
Main Emphasis ◽  
Solid Liquid Interface ◽  
Solid Liquid

ABSTRACTHeat flow calculations, based on the main assumption that the energy of the incident pulse is instantaneously and locally converted into heat, are used to review the results of laser pulse annealing and impurities behaviour in ion implanted semiconductors. The crystallization behaviour of amorphous layers, the velocity of the solid-liquid interface and impurity redistribution are detailed with the main emphasis on the relevance of the parameters (laser wavelen gth, pulse duration and energy density, substrate temperature, etc.) that can be experimentally controlled. Comparison with the latest experimental results is also given.

Transient Conductance Measurements During Pulsed Laser Annealing

1981 ◽  
Vol 4 ◽  
Author(s):  
M. O. Thompson ◽  
G. J. Galvin ◽  
J. W. Mayer ◽  
R. B. Hammond ◽  
N. Paulter ◽  
...  
Keyword(s):  
Single Crystal ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Interface Velocity ◽  
Laser Pulses ◽  
Molten Layer ◽  
Pulsed Laser Annealing ◽  
Complete Melting ◽  
Solid Liquid Interface ◽  
Solid Liquid

ABSTRACTMeasurements were made of the conductance of single crystal Au-doped Si and silicon-on-sapphire (SOS) during irradiation with 30 nsec ruby laser pulses. After the decay of the photoconductive response, the sample conductance is determined primarily by the thickness and conductivity of the molten layer. For the single crystal Au-doped Si, the solid-liquid interface velocity during recrystallization was determined from the current transient to be 2.5 m/sec for energy densities between 1.9 and 2.6 J/cm2, in close agreement with numerical simulations based on a thermal model of heat flow. SOS samples showed a strongly reduced photoconductive response, allowing the melt front to be observed also. For complete melting of a 0.4 μm Si layer, the regrowth velocity was 2.4 m/sec.

Electrophysical and photoelectrical properties of epitaxial films of Hg1−xCdxTe (x ≈ 0.2) after laser treatment

1992 ◽  
Vol 70 (5) ◽  
pp. 357-360 ◽  
Author(s):  
M. Kuźma ◽  
C. Abeynayake ◽  
E. M. Sheregii ◽  
Y. O. Ugrin ◽  
I. S. Virt
Keyword(s):  
Energy Density ◽  
Laser Pulse ◽  
Laser Treatment ◽  
Cluster Model ◽  
Spectral Dependence ◽  
Laser Annealing ◽  
Epitaxial Films ◽  
Photoelectrical Properties ◽  
Before And After ◽  
Nonequilibrium Carriers

Changes in the electrophysical and photoelectrical properties of epitaxial films of Hg1−xCdxTe (x ≈ 0.2) due to laser annealing are studied. Experimental fits for the dependence of the resistance of the film to the energy density of the laser pulse, to the time, as well as to the temperature are obtained before and after laser annealing. Further, changes in the lifetime of minority nonequilibrium carriers of charge and the spectral dependence of the photoconductivity because of laser annealing are shown. Experimental results are interpreted on the basis of the two cluster model for electro- and photoconductivity.

Light Absorption Effects on the Nd Laser Annealing of Ion Implanted Silicon

1981 ◽  
Vol 4 ◽  
Author(s):  
P. Baeri ◽  
A.E. Bapbarino ◽  
S.U. Campisano ◽  
M.G. Grimaldi ◽  
G. Foti ◽  
...  
Keyword(s):  
Energy Density ◽  
Heat Flow ◽  
Low Temperature ◽  
Laser Annealing ◽  
Amorphous Material ◽  
Amorphous Layer ◽  
Absorbed Energy ◽  
Pre Treatment ◽  
Crystallization Onset ◽  
Ion Implanted

ABSTRACTThe crystallization onset and the annealing thresholds have been nmeasured as a function of the absorbed energy density in ion implanted amorphous silicon irradiated with nanosecond Nd pulse. Thin amorphous layers (∼500 Å) require higher thresholds ccapared with thick (∼4000 Å) amorphous layers. This result can be explained in terms of balance between absorbed energy and heat flow. For a given thickness of the amorphous layer the thresholds depend on the absorption coefficient of the amorphous material. This last parameter has been varied frcm 104 to 102 CM−1 by low temperature (T<400°C) pre-treatment of the ion implanted sample. The observed drastic variations of both crystallizazion and annealing thresholds agree well with nunerical evaluation of heat flow.

Investigation of Electronic Excitation Crystallization Enhancement in Amorphous Gesb Films Upon Ultrashort Laser Pulse Irradiation

1995 ◽  
Vol 397 ◽  
Author(s):  
J. Solis ◽  
C.N. Afonso ◽  
S.C.W. Hyde ◽  
N.P. Barry ◽  
P.M.W. French
Keyword(s):  
Energy Density ◽  
Laser Pulse ◽  
Pulse Duration ◽  
Ultrashort Laser Pulse ◽  
Electronic Excitation ◽  
Pulse Length ◽  
Experimental Resolution ◽  
Flow Through ◽  
Ultrashort Laser ◽  
Induced Crystallization

ABSTRACTPulsed laser induced crystallization of amorphous GeSb films has been studied as a function of the laser pulse duration. The energy density crystallization threshold has been determined for pulses in the range from 400 fs to 8 ns. The threshold is observed to increase substantially for pulse durations in the ns range due to the existence of heat flow through the substrate while the pulse is still being absorbed. The energy density crystallization threshold remains constant within the experimental resolution as the pulse duration is decreased down to 800 fs. For the shortest pulse length used, (400 fs), a decrease in the threshold is observed, suggesting the possible existence of electronic excitation enhanced crystallization.

Velocity and Orientation Dependence of Solute Trapping In Si

1980 ◽  
Vol 1 ◽  
Author(s):  
P. Baeri ◽  
G. Foti ◽  
J. M. Poate ◽  
S. U. Campisano ◽  
E. Rimini ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Substrate Temperature ◽  
Laser Irradiation ◽  
Pulse Duration ◽  
Crystal Orientation ◽  
Interface Velocity ◽  
Orientation Dependence ◽  
Laser Pulse Duration ◽  
Solid Interface ◽  
Interfacial Segregation

ABSTRACTThe segregation phenomena of In, Ga and Bi in Si have been investigated as a function of the liquid-solid interface velocity following laser irradiation. The crystallization velocity has been changed within the range 0.8–5 m/s by varying either the substrate temperature during irradiation or the laser pulse duration. The measured interfacial segregation coefficients depend critically on the velocity and on the crystal orientation of the solidifying plane.

Stable liquid-solid interface of lithium metal anode enabled by micro-region meshing

Nanoscale ◽  
2021 ◽  
Author(s):  
Jianzong Man ◽  
Kun Liu ◽  
Yehong Du ◽  
Xinyu Wang ◽  
Song Li ◽  
...  
Keyword(s):  
Energy Density ◽  
Lithium Ion ◽  
High Energy ◽  
High Energy Density ◽  
Lithium Metal ◽  
Metal Anode ◽  
Battery Lifetime ◽  
Lithium Metal Anode ◽  
Solid Liquid Interface ◽  
Solid Liquid

Although lithium metal is regarded as the most promising anode for high energy density lithium ion batteries, the unstable solid-liquid interface during cycling severely shortens the battery lifetime. The Li...

Creation of a pn heterojunction in Hg1−xCdxTe (x ≈ 0.2) by laser annealing

1995 ◽  
Vol 73 (3-4) ◽  
pp. 174-176
Author(s):  
E. Sheregii ◽  
M. Kuźma ◽  
C. Abeynayake ◽  
M. Pociask
Keyword(s):  
Energy Density ◽  
Laser Treatment ◽  
Solid Solutions ◽  
Nd:Yag Laser ◽  
Laser Annealing ◽  
Computer Modelling ◽  
Mass Transportation ◽  
X Ray ◽  
Current Voltage ◽  
Current Voltage Characteristics

A highly photosensitive diode area was created in solid solutions of Hg1−xCdxTe (x ≈ m 0.2) (MCT) without melting its surface. The idea of the possible formation of pn heterojunctions, which was indicated by computer modelling of the mass transportation processes under laser treatment of the MCT, was experimentally realized. MCT samples were irradiated with an Nd:YAG laser having an energy density of 0.7 J cm−2. The presence of a heterojunction on a surface not far below the upper surface has been verified by photovoltaic measurements and X-ray microanalysis as well as by current–voltage characteristics.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

Laser pulse duration effects in Xe2+ ions induced by multiphoton absorption at 0.53 μm

1983 ◽  
Vol 44 (11) ◽  
pp. 1247-1255 ◽  
Author(s):  
A. L'Huillier ◽  
L.A. Lompre ◽  
G. Mainfray ◽  
C. Manus
Keyword(s):  
Laser Pulse ◽  
Pulse Duration ◽  
Laser Pulse Duration ◽  
Multiphoton Absorption
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