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Title: Selective etching of SiO[sub 2] over polycrystalline silicon using CHF[sub 3] in an inductively coupled plasma reactor. [SiO[sub 2]; Si; fluorocarbons]

Abstract

Selective etching of SiO[sub 2] over polycrystalline silicon has been studied using CHF[sub 3] in an inductively coupled plasma reactor (ICP). Inductive powers between 200 and 1400 W, as well as pressures of 6, 10, and 20 mTorr were used in this study of the etch rate and selectivity behaviors for silicon dioxide, silicon, and passively deposited fluorocarbon films. Using [ital in situ] ellipsometry, the etch rates for all three of these materials were obtained for a self-bias voltage of [minus]85 V, as well as passive deposition rates of fluorocarbon films. X-ray photoelectron spectroscopy has been used to examine the composition of steady-state fluorocarbon films present on the surfaces of polycrystalline silicon, and silicon dioxide during etching at high and low inductive powers. The dependence of the silicon etching behavior is shown to be clearly linked to the fluorocarbon polymerization and etching behavior. Thus, the polymerization and etching behavior of the fluorocarbon is the overwhelming parameter that governs the etch selectivity process within the ICP. Selectivities of oxide to silicon are determined to increase with the inductive power, and are found to be the highest at the intermediate pressure of 10 mTorr. While the stoichiometry of the fluorocarbon films aremore » critical factors in determining the overall etch rate behavior, the fluorocarbon film thickness on the polycrystalline and crystalline silicon is the dominant factor in determining the SiO[sub 2] over silicon etch selectivity. The mechanisms involved in attaining high selectivity are dominated by a defluorination of the fluorocarbon steady-state film on polycrystalline silicon, while maintaining a high ion current to the wafer. [copyright] [ital 1999 American Vacuum Society.]« less

Authors:
; ; ; ; ;  [1]
  1. (Department of Physics, University at Albany, State University of New York, Albany, New York 12222 (United States))
Publication Date:
OSTI Identifier:
6377833
Alternate Identifier(s):
OSTI ID: 6377833
Resource Type:
Journal Article
Journal Name:
Journal of Vacuum Science and Technology, A
Additional Journal Information:
Journal Volume: 17:5; Journal ID: ISSN 0734-2101
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ELLIPSOMETRY; ETCHING; PHOTOELECTRON SPECTROSCOPY; PLASMA; POLYCRYSTALS; POLYMERIZATION; SILICON; SILICON COMPOUNDS; SILICON OXIDES; CHALCOGENIDES; CHEMICAL REACTIONS; CRYSTALS; ELECTRON SPECTROSCOPY; ELEMENTS; MEASURING METHODS; OXIDES; OXYGEN COMPOUNDS; SEMIMETALS; SPECTROSCOPY; SURFACE FINISHING 400201* -- Chemical & Physicochemical Properties; 700300 -- Plasma Physics & Fusion Research-- (1992-)

Citation Formats

Rueger, N.R., Doemling, M.F., Schaepkens, M., Beulens, J.J., Standaert, T.E., and Oehrlein, G.S. Selective etching of SiO[sub 2] over polycrystalline silicon using CHF[sub 3] in an inductively coupled plasma reactor. [SiO[sub 2]; Si; fluorocarbons]. United States: N. p., 1999. Web. doi:10.1116/1.581987.
Rueger, N.R., Doemling, M.F., Schaepkens, M., Beulens, J.J., Standaert, T.E., & Oehrlein, G.S. Selective etching of SiO[sub 2] over polycrystalline silicon using CHF[sub 3] in an inductively coupled plasma reactor. [SiO[sub 2]; Si; fluorocarbons]. United States. doi:10.1116/1.581987.
Rueger, N.R., Doemling, M.F., Schaepkens, M., Beulens, J.J., Standaert, T.E., and Oehrlein, G.S. Wed . "Selective etching of SiO[sub 2] over polycrystalline silicon using CHF[sub 3] in an inductively coupled plasma reactor. [SiO[sub 2]; Si; fluorocarbons]". United States. doi:10.1116/1.581987.
@article{osti_6377833,
title = {Selective etching of SiO[sub 2] over polycrystalline silicon using CHF[sub 3] in an inductively coupled plasma reactor. [SiO[sub 2]; Si; fluorocarbons]},
author = {Rueger, N.R. and Doemling, M.F. and Schaepkens, M. and Beulens, J.J. and Standaert, T.E. and Oehrlein, G.S.},
abstractNote = {Selective etching of SiO[sub 2] over polycrystalline silicon has been studied using CHF[sub 3] in an inductively coupled plasma reactor (ICP). Inductive powers between 200 and 1400 W, as well as pressures of 6, 10, and 20 mTorr were used in this study of the etch rate and selectivity behaviors for silicon dioxide, silicon, and passively deposited fluorocarbon films. Using [ital in situ] ellipsometry, the etch rates for all three of these materials were obtained for a self-bias voltage of [minus]85 V, as well as passive deposition rates of fluorocarbon films. X-ray photoelectron spectroscopy has been used to examine the composition of steady-state fluorocarbon films present on the surfaces of polycrystalline silicon, and silicon dioxide during etching at high and low inductive powers. The dependence of the silicon etching behavior is shown to be clearly linked to the fluorocarbon polymerization and etching behavior. Thus, the polymerization and etching behavior of the fluorocarbon is the overwhelming parameter that governs the etch selectivity process within the ICP. Selectivities of oxide to silicon are determined to increase with the inductive power, and are found to be the highest at the intermediate pressure of 10 mTorr. While the stoichiometry of the fluorocarbon films are critical factors in determining the overall etch rate behavior, the fluorocarbon film thickness on the polycrystalline and crystalline silicon is the dominant factor in determining the SiO[sub 2] over silicon etch selectivity. The mechanisms involved in attaining high selectivity are dominated by a defluorination of the fluorocarbon steady-state film on polycrystalline silicon, while maintaining a high ion current to the wafer. [copyright] [ital 1999 American Vacuum Society.]},
doi = {10.1116/1.581987},
journal = {Journal of Vacuum Science and Technology, A},
issn = {0734-2101},
number = ,
volume = 17:5,
place = {United States},
year = {1999},
month = {9}
}