INCREASING OF THE SHARPNESS OF p–n JUNCTIONS BY LASER PULSES

NANO ◽  
2011 ◽  
Vol 06 (01) ◽  
pp. 31-40 ◽  
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Spatial Distribution ◽  
Laser Pulse ◽  
Annealing Time ◽  
Multilayer Structure ◽  
Surface Region ◽  
Laser Pulses ◽  
Dopant Distribution ◽  
Dopant Redistribution ◽  
Junction Rectifiers

Dopant redistribution in a multilayer structure during annealing by laser pulses for production of implanted-junction rectifiers has been analyzed. The analysis shows that heating the surface region of the multilayer structure leads to increasing of previously described effect of simultaneously increasing of sharpness of implanted-junction rectifier and homogeneity of dopant distribution in doped area. It was found that the theoretical spatial distribution of dopant agrees with the experimental one. Annealing time has been optimized for laser pulse annealing.

LOCAL DOPING AND OPTIMAL ANNEALING OF A MESH MULTILAYER STRUCTURE TO DECREASE THE SPATIAL DIMENSIONS OF INTEGRATED p–n-JUNCTIONS

NANO ◽  
2009 ◽  
Vol 04 (05) ◽  
pp. 303-323 ◽  
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Integrated Circuits ◽  
Annealing Time ◽  
Multilayer Structure ◽  
Paper Analysis ◽  
Bipolar Transistor ◽  
Multilayer Structures ◽  
Dopant Distribution ◽  
Spatial Dimensions ◽  
Dopant Redistribution ◽  
Junction Rectifiers

It has been recently shown that inhomogeneity of a multilayer structure and optimization of annealing time give us the possibility to decrease the depth of p–n-junctions, which were produced in the structures. The additional to the considered effect is increasing of homogeneity of dopant distribution in enriched by the dopant area of p–n-junction. In the present paper analysis of dopant redistribution in a multilayer structures during production a series of p–n-junctions, which was produced in the multilayer structures, has been done. We consider an approach to increase the sharpness of both diffused-junction and implanted-junction rectifiers, which comprise in a bipolar transistor or thyristor, and increasing of homogeneity of dopants distributions in enriched by the dopants areas of p–n-junctions. The approach gives us possibility to increase the degree of integration of p–n-junctions, which was produced as elements of integrated circuits. Optimization of annealing time for simultaneously increasing of the sharpness and homogeneity has been done.

INFLUENCE OF MECHANICAL STRESS IN A MULTILAYER STRUCTURE ON SPATIAL DISTRIBUTION OF DOPANTS IN IMPLANTED-JUNCTION AND DIFFUSION-JUNCTION RECTIFIERS

2010 ◽  
Vol 24 (09) ◽  
pp. 867-895 ◽  
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Diffusion Coefficient ◽  
Spatial Distribution ◽  
Mechanical Stress ◽  
Multilayer Structure ◽  
Spatial Dimensions ◽  
Dopant Redistribution ◽  
Additional Reduction ◽  
And Diffusion ◽  
Junction Rectifiers

The influence of mechanical stress in a multilayer structure on spatial distribution of dopants in implanted-junction and diffusion-junction rectifiers, which was produced in the structure has been analyzed. It is shown that the stress leads to additional reduction of spatial dimensions of the p–n junction in comparison with the reduction — a result of inhomogeneity — of the diffusion coefficient of dopant and other parameters of dopant redistribution (see, for example, Refs. 1–3).

OPTIMIZATION OF DIFFUSION PROCESS FOR PRODUCTION OF SYSTEMS OF DIFFUSED-JUNCTION RECTIFIERS

2010 ◽  
Vol 24 (29) ◽  
pp. 5793-5806
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Diffusion Process ◽  
Annealing Time ◽  
Diffusion Coefficients ◽  
Multilayer Structure ◽  
Bipolar Transistors ◽  
Dopant Distribution ◽  
The Difference ◽  
Junction Rectifiers

It has been recently shown that difference between diffusion coefficients of dopant in layers of a multilayer structure leads to increasing of sharpness of diffusion-junction rectifier (see, for example, E. L. Pankratov, Phys. Rev. B72(7), 075201 (2005); E. L. Pankratov and B. Spagnolo, Eur. Phys. J. B 46(1), 15 (2005).), which was formed in the multilayer structure after appropriate choosing of materials of layers. It has been also shown that the difference between the diffusion coefficients also leads to increasing of homogeneity of dopant distribution in doped area. In this paper, both the effects (together increasing of sharpness of p–n-junction and increasing of homogeneity of dopant distribution) have been used to produce a system of p–n-junctions (such as bipolar transistors). Annealing time has been optimized to increase simultaneously the sharpness and the homogeneity.

scholarly journals Investigation of propagation dynamics of material deformations caused by laser pulse action

2021 ◽  
Vol 2144 (1) ◽  
pp. 012008
Author(s):  
A F Banishev
Keyword(s):  
Spatial Distribution ◽  
Laser Pulse ◽  
Laser Pulses ◽  
Pulse Action ◽  
Mechanical Stresses ◽  
Powerful Laser ◽  
Phosphor Powder ◽  
Glow Intensity ◽  
Evolution Dynamics ◽  
Laser Pulse Action

Abstract The mechanoluminescent materials attract increasing attention of scientists due to their capability of visualizing the mechanical stresses and deformations experienced by them. The deformations of materials arising under the action of powerful laser pulses were studied. The composite mechanoluminescent materials based on the polymer and phosphor powder were used for visualization and registration of deformation evolution dynamics. The mechanoluminescent materials were deposited on the surface of the materials under study. It has been shown that the spatial distribution of glow intensity of the mechanoluminescent layer and the rate of its change make possible judging the value and rate of material deformation under laser pulses.

SYNCHRONIZATION OF IMPURITIES INFUSION FOR PRODUCTION OF A SEQUENCE OF DIFFUSED-JUNCTION RECTIFIERS

NANO ◽  
2009 ◽  
Vol 04 (03) ◽  
pp. 177-188
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Annealing Time ◽  
Dopant Distribution ◽  
Junction Rectifiers

An approach to increase both the sharpness of a series of diffused-junction rectifiers and to increase the homogeneity of dopant distribution in dopant-enriched areas has been considered. The conditions to obtain both the effects are determined. Annealing time has been optimized for increasing simultaneously the sharpness and the homogeneity. The dependence of the optimal annealing time on several parameters of the model have been analyzed.

DECREASING OF SPATIAL DIMENSION OF A SERIAL OF DIFFUSED-JUNCTION RECTIFIERS IN A MULTILAYER STRUCTURE IN ACCOUNT WITH NONLINEAR EFFECTS: OPTIMIZATION OF ANNEALING TIME

2009 ◽  
Vol 23 (22) ◽  
pp. 4637-4653
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Annealing Time ◽  
Multilayer Structure ◽  
Nonlinear Effects ◽  
Spatial Dimension ◽  
Bipolar Transistors ◽  
Impurity Distribution ◽  
Junction Rectifiers

It has been recently shown, that inhomogeneity of a multilayer structure (MS) leads to increase in sharpness of diffused-junction rectifier (see, for example, Refs. 1 and 2), which were formed in the MS. It has been also shown, that together with increasing of the sharpness homogeneity of impurity distribution in doped area increases. In this paper, both the effects (together increasing of sharpness of p–n-junction and increasing of homogeneity of impurity distribution) have been used for production of a system of a serial p–n-junctions (such as bipolar transistors). Annealing time has been optimized for increasing simultaneously the sharpness and the homogeneity.

REDISTRIBUTION OF A DOPANT DURING ANNEALING OF RADIATION DEFECTS IN A MULTILAYER STRUCTURE BY LASER SCANS FOR PRODUCTION OF AN IMPLANTED-JUNCTION RECTIFIER

2008 ◽  
Vol 07 (04n05) ◽  
pp. 187-197 ◽  
Author(s):  
E. L. PANKRATOV
Keyword(s):  
Diffusion Coefficient ◽  
Temperature Dependence ◽  
Multilayer Structure ◽  
Radiation Defects ◽  
Dopant Distribution ◽  
Dopant Redistribution

In this paper, we analyze dopant redistribution in a multilayer structure during laser scan annealing of radiation defects for the production of an implanted-junction rectifier, taking account of the temperature dependence of the diffusion coefficient. It is shown that inhomogeneity of the structure leads to increase in the sharpness of the implanted-junction rectifier and the homogeneity of the dopant distribution in the doped area. Some conditions on properties of the considered multilayer structure, which correspond to increase in the sharpness and the homogeneity, are determined.

scholarly journals Production of ion beams in high-power laser–plasma interactions and their applications

2004 ◽  
Vol 22 (1) ◽  
pp. 19-24 ◽  
Author(s):  
F. PEGORARO ◽  
S. ATZENI ◽  
M. BORGHESI ◽  
S. BULANOV ◽  
T. ESIRKEPOV ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Medical Physics ◽  
Ion Beam ◽  
Laser Pulses ◽  
Ion Beams ◽  
Laser Plasma Interactions ◽  
Physical Mechanisms ◽  
Short Laser Pulses ◽  
Laser Pulse Intensity ◽  
Target Design

Energetic ion beams are produced during the interaction of ultrahigh-intensity, short laser pulses with plasmas. These laser-produced ion beams have important applications ranging from the fast ignition of thermonuclear targets to proton imaging, deep proton lithography, medical physics, and injectors for conventional accelerators. Although the basic physical mechanisms of ion beam generation in the plasma produced by the laser pulse interaction with the target are common to all these applications, each application requires a specific optimization of the ion beam properties, that is, an appropriate choice of the target design and of the laser pulse intensity, shape, and duration.

scholarly journals Electron Symmetry Breaking during Attosecond Charge Migration Induced by Laser Pulses: Point Group Analyses for Quantum Dynamics

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 205
Author(s):  
Dietrich Haase ◽  
Gunter Hermann ◽  
Jörn Manz ◽  
Vincent Pohl ◽  
Jean Christophe Tremblay
Keyword(s):  
Laser Pulse ◽  
Symmetry Breaking ◽  
Electric Fields ◽  
Quantum Dynamics ◽  
Point Group ◽  
Laser Pulses ◽  
Charge Migration ◽  
Laser Control ◽  
The One ◽  
Superposition States

Quantum simulations of the electron dynamics of oriented benzene and Mg-porphyrin driven by short (<10 fs) laser pulses yield electron symmetry breaking during attosecond charge migration. Nuclear motions are negligible on this time domain, i.e., the point group symmetries G = D6h and D4h of the nuclear scaffolds are conserved. At the same time, the symmetries of the one-electron densities are broken, however, to specific subgroups of G for the excited superposition states. These subgroups depend on the polarization and on the electric fields of the laser pulses. They can be determined either by inspection of the symmetry elements of the one-electron density which represents charge migration after the laser pulse, or by a new and more efficient group-theoretical approach. The results agree perfectly with each other. They suggest laser control of symmetry breaking. The choice of the target subgroup is restricted, however, by a new theorem, i.e., it must contain the symmetry group of the time-dependent electronic Hamiltonian of the oriented molecule interacting with the laser pulse(s). This theorem can also be applied to confirm or to falsify complementary suggestions of electron symmetry breaking by laser pulses.

scholarly journals Cylindrically and non-cylindrically symmetric expansion dynamics of tin microdroplets after ultrashort laser pulse impact

2021 ◽  
Vol 127 (2) ◽  
Author(s):  
Tiago de Faria Pinto ◽  
Jan Mathijssen ◽  
Randy Meijer ◽  
Hao Zhang ◽  
Alex Bayerle ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Droplet Deformation ◽  
Cylindrically Symmetric ◽  
Linearly Polarized ◽  
Particle Hydrodynamics ◽  
Deformation Dynamics ◽  
Smoothed Particle ◽  
Asymmetric Shock

AbstractIn this work, the expansion dynamics of liquid tin micro-droplets irradiated by femtosecond laser pulses were investigated. The effects of laser pulse duration, energy, and polarization on ablation, cavitation, and spallation dynamics were studied using laser pulse durations ranging from 220 fs to 10 ps, with energies ranging from 1 to 5 mJ, for micro-droplets with an initial radius of 15 and 23 $$\upmu$$ μ m. Using linearly polarized laser pulses, cylindrically asymmetric shock waves were produced, leading to novel non-symmetric target shapes, the asymmetry of which was studied as a function of laser pulse parameters and droplet size. A good qualitative agreement was obtained between smoothed-particle hydrodynamics simulations and high-resolution stroboscopic experimental data of the droplet deformation dynamics.

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