DocumentCode :
1140952
Title :
Plasma molding over surface topography: Simulation of ion flow, and energy and angular distributions over steps in RF high-density plasmas
Author :
Kim, Doosik ; Economou, Demetre J.
Author_Institution :
Dept. of Chem. Eng., Univ. of Houston, TX, USA
Volume :
30
Issue :
5
fYear :
2002
fDate :
10/1/2002 12:00:00 AM
Firstpage :
2048
Lastpage :
2058
Abstract :
A two-dimensional fluid/Monte Carlo (MC) simulation model was developed to study plasma "molding" over surface topography. The radio frequency (RF) sheath potential evolution, ion density, and flux profiles over the surface were predicted with a self-consistent fluid simulation. The trajectories of ions and energetic neutrals (resulting by ion neutralization on surfaces or charge exchange collisions in the gas phase) were then followed with a MC simulation. In this paper, ion flow, energy and angular distributions of ions, and energetic neutrals bombarding an otherwise planar surface with a step are reported. The step height was comparable to the sheath thickness for the RF high-density plasma considered. As one approaches the step sidewall, the ion flux decreases, the ion energy distribution narrows, and the ion impact angle increases drastically. The ion impact angle at the foot of the step scales with the ratio of sheath thickness to step height. The energetic neutral flux is found to be comparable to the ion flux on the horizontal surface near the step sidewall. Simulation results are in good agreement with experimental data on ion flux and ion energy and angular distributions near the step.
Keywords :
Monte Carlo methods; ion-surface impact; plasma density; plasma flow; plasma sheaths; plasma simulation; plasma-beam interactions; surface topography; RF high-density plasmas; angular distributions; energetic neutral bombardment; energetic neutral flux; energetic neutral trajectories; energy distributions; flux profiles; ion density; ion energy; ion energy distribution; ion flow; ion flux; ion impact angle; ion neutralization; ion trajectories; planar surface; plasma molding; radio frequency sheath potential evolution; self-consistent fluid simulation; sheath over steps; sheath thickness; step height; step sidewall; surface topography; two-dimensional fluid/Monte Carlo simulation model; Etching; Plasma applications; Plasma density; Plasma immersion ion implantation; Plasma materials processing; Plasma sheaths; Plasma simulation; Plasma sources; Radio frequency; Surface topography;
fLanguage :
English
Journal_Title :
Plasma Science, IEEE Transactions on
Publisher :
ieee
ISSN :
0093-3813
Type :
jour
DOI :
10.1109/TPS.2002.805326
Filename :
1178023
Link To Document :
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