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Title: Dynamics of collisionless rf plasma sheaths

Abstract

The behavior of rf plasma sheaths has been the subject of much scientific study and also is technologically important for plasma etching and deposition in the manufacture of integrated circuits. This paper presents a semianalytic model of rf sheaths and describes an experiment that tested the model. An approximation to the first integral of the Poisson equation allows solving for the response of plasma sheaths to an imposed rf bias voltage. This approximation enables the plasma sheaths to be included within an electrical model of the plasma and external rf circuit components, and affords a prediction of the ion energy distributions impacting the electrodes, which are in contact with the plasma. The model is a significant advance beyond previous sheath models because it has no restriction on the ratio of the rf period to the ion transit time across the sheath. The model is applicable to those high-density, low-pressure plasmas in which the Debye length is a small fraction of the ion mean-free path, which itself is a small fraction of the plasma dimension. The experimental test of the model was conducted by comparing the predicted and measured rf potential, current, and power at the sheath adjacent to a capacitivelymore » coupled, rf-biased electrode in a plasma reactor with argon discharges sustained by an inductively coupled plasma source. The comparisons included both linear and nonlinear components of the rf electrical parameters. Results of the experiment were in substantial agreement with model predictions. {copyright} {ital 1997 American Institute of Physics.}« less

Authors:
;  [1]
  1. Sandia National Laboratories, Box 5800, Albuquerque, New Mexico 87185-1423 (United States)
Publication Date:
Research Org.:
Sandia National Laboratory
OSTI Identifier:
542559
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 82; Journal Issue: 8; Other Information: PBD: Oct 1997
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION; PLASMA SHEATH; DYNAMICS; PLASMA DIAGNOSTICS; ETCHING; POISSON EQUATION; DEBYE LENGTH; ARGON; PLASMA DENSITY

Citation Formats

Miller, P A, and Riley, M E. Dynamics of collisionless rf plasma sheaths. United States: N. p., 1997. Web. doi:10.1063/1.365732.
Miller, P A, & Riley, M E. Dynamics of collisionless rf plasma sheaths. United States. doi:10.1063/1.365732.
Miller, P A, and Riley, M E. Wed . "Dynamics of collisionless rf plasma sheaths". United States. doi:10.1063/1.365732.
@article{osti_542559,
title = {Dynamics of collisionless rf plasma sheaths},
author = {Miller, P A and Riley, M E},
abstractNote = {The behavior of rf plasma sheaths has been the subject of much scientific study and also is technologically important for plasma etching and deposition in the manufacture of integrated circuits. This paper presents a semianalytic model of rf sheaths and describes an experiment that tested the model. An approximation to the first integral of the Poisson equation allows solving for the response of plasma sheaths to an imposed rf bias voltage. This approximation enables the plasma sheaths to be included within an electrical model of the plasma and external rf circuit components, and affords a prediction of the ion energy distributions impacting the electrodes, which are in contact with the plasma. The model is a significant advance beyond previous sheath models because it has no restriction on the ratio of the rf period to the ion transit time across the sheath. The model is applicable to those high-density, low-pressure plasmas in which the Debye length is a small fraction of the ion mean-free path, which itself is a small fraction of the plasma dimension. The experimental test of the model was conducted by comparing the predicted and measured rf potential, current, and power at the sheath adjacent to a capacitively coupled, rf-biased electrode in a plasma reactor with argon discharges sustained by an inductively coupled plasma source. The comparisons included both linear and nonlinear components of the rf electrical parameters. Results of the experiment were in substantial agreement with model predictions. {copyright} {ital 1997 American Institute of Physics.}},
doi = {10.1063/1.365732},
journal = {Journal of Applied Physics},
number = 8,
volume = 82,
place = {United States},
year = {1997},
month = {10}
}