Monte Carlo Simulations of Ionized Impurities Profile in a Semiconductor in External Parabolic Potential
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Date
2020-08-08
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Addis Ababa University
Abstract
In this thesis we have investigated impurities profiles in a semiconductor layers,
using Monte Carlo simulation technique in an external parabolic potential. By ignoring
impurity - impurity Coulomb’s interaction, first we considered impurities
diffusion in the presence of external parabolic potential that has minimum at the
center of the semiconductor at a different temperatures. The model was modified
and included the impurity impurity Coulomb’s interaction. Using Arrhenius type
equation, we have performed Monte Carlo simulation to predict impurities profile
for different amplitudes of external parabolic potential, temperatures and impurities
density per sites. When we approximated the non - linear potential as one
dimensional parabola which has a minimum at the mid point of the semiconductor
layer, the impurity is accumulated in the central region. Our results show that
the external potential has influenced the diffusion towards the center even though
an internal potential has opposite effect. Moreover the impurity distribution has a
Gaussian profiles that becomes sharper when the amplitude of external parabolic
potential is increased. Our simulation results were compared with the pervious related
works. The variation of the gaussian width within a temperature and dopant
density per site were also observed that as the temperature increases the plots becomes
broaden. Similarly, as the dopant density per site at the initial increases the
impurities per site around the center of the graph becomes higher and broaden.
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Keywords
Monte Carlo Simulations, Ionized Impurities Profile, Semiconductor, External Parabolic Potential