Atomistic Simulations of Effect of Coulombic Interactions on Carrier Fluctuations in Doped Silicon

2003 ◽  
Vol 765 ◽  
Author(s):  
Zudian Qin ◽  
Scott T. Dunham
Keyword(s):  
Electrical Potential ◽  
Standard Condition ◽  
Atomistic Simulations ◽  
Coulombic Interactions ◽  
Coulombic Repulsion ◽  
Lattice Monte Carlo ◽  
Kinetic Lattice Monte Carlo ◽  
Dopant Redistribution ◽  
Charged Defects ◽  
Quantum Perturbation Theory

AbstractCarrier distributions associated with point charges in silicon solved with quantum perturbation theory are used to determine Coulombic interactions between charged defects in the presence of carrier screening. The resulting interactions are used in kinetic lattice Monte Carlo (KLMC) simulations of point defect-mediated diffusion to study dopant redistribution and associated variations in carrier concentration. Over a broad range of doping concentrations and temperatures, Coulombic repulsion between like dopants leads to ordering, resulting in a more uniform electrical potential distribution and therefore reduced variations in device performance compared with random doping, the standard condition assumed in previous doping fluctuation analyses.

3D Atomistic Simulations of Submicron Device Fabrication

1997 ◽  
Vol 490 ◽  
Author(s):  
Marius M. Buneat ◽  
Scott T. Dunham
Keyword(s):  
Monte Carlo ◽  
Local Environment ◽  
Channel Length ◽  
Deep Submicron ◽  
Device Fabrication ◽  
Atomistic Simulations ◽  
Atomic Processes ◽  
Lattice Monte Carlo ◽  
Submicron Devices ◽  
Dopant Redistribution

ABSTRACTWe use the Lattice Monte Carlo method to simulate the coupled motion of vacancies, interstitials and dopants during the annealing of a 50nm channel length NMOS structure. The initial defect locations are taken from Monte Carlo ion implantation simulations. The resulting defects diffuse, recombine, pair and cluster, with rates of these atomic processes calculated based on the local environment. Dopant redistribution occurs via both displacement by vacancies as well as the formation and diffusion of mobile boron and arsenic interstitials. We use these simulations to demonstrate the potential of atomistic simulations for deep submicron devices and to explore the influence of atomistic processes on macroscopic behavior.

Understanding ion beam synthesis of nanostructures: Modeling and atomistic simulations

2000 ◽  
Vol 647 ◽  
Author(s):  
M. Strobel ◽  
K.-H. Heinig ◽  
W. Möller
Keyword(s):  
Ion Implantation ◽  
Ion Beam ◽  
Monte Carlo Model ◽  
Atomistic Simulations ◽  
Ion Energy ◽  
Lattice Monte Carlo ◽  
Supersaturated Solid Solutions ◽  
Ion Beam Synthesis ◽  
Thermodynamic Effects ◽  
Low Dimensional

AbstractIon implantation, specified by parameters like ion energy, ion fluence, ion flux and sub-strate temperature, has become a well-established tool to synthesize buried low-dimensional nanostructures. In general, in ion beam synthesis the evolution of nanostructures is determined by the competition between ballistic and thermodynamic effects. A kinetic 3D lattice Monte-Carlo model is introduced, which allows for a proper incorporation of collisional mixing and phase separation within supersaturated solid-solutions. It is shown, that for both the ballistically and thermodynamically dominated regimes, the Gibbs-Thomson relation is the key ingredient in understanding nanocluster evolution. Various aspects of precipitate evolution during implantation, formation of ordered arrays of nanophase domains by focused ion implantation and compound nanocluster synthesis are discussed.

scholarly journals Modeling Fermi Level Effects in Atomistic Simulations

2002 ◽  
Vol 717 ◽  
Author(s):  
Zudian Qin ◽  
Scott T. Dunham
Keyword(s):  
Fermi Level ◽  
Atomistic Simulations ◽  
Electron Hole ◽  
Lattice Monte Carlo ◽  
Coupled Diffusion ◽  
External Point ◽  
Work Variations ◽  
Dopant Atoms ◽  
Charged Point Defect ◽  
Charged Point

AbstractIn this work, variations in electron potential are incorporated into a Kinetic Lattice Monte Carlo (KLMC) simulator and applied to dopant diffusion in silicon. To account for the effect of dopants, the charge redistribution induced by an external point charge immersed in an electron (hole) sea is solved numerically using the quantum perturbation method. The local carrier concentrations are then determined by summing contributions from all ionized dopant atoms and charged point defects, from which the Fermi level of the system is derived by the Boltzmann equation. KLMC simulations with incorporated Fermi level effects are demonstrated for charged point defect concentration as a function of Fermi level, coupled diffusion phenomenon and field effect on doping fluctuations.

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