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Title: Laser-induced fluorescence and Langmuir probe determination of Cl{sub 2}{sup +} and Cl{sup +} absolute densities in transformer-coupled chlorine plasmas

Abstract

Laser induced fluorescence detection of Cl{sub 2}{sup +} has been used to track their relative concentration in a high-density inductively (transformer) coupled (TCP) 10 mTorr chlorine plasma as a function of the 13.56 MHz radio frequency (rf) power. This relative Cl{sub 2}{sup +} number density was compared to the total absolute positive ion density (n{sub i}{sup +}=n{sub Cl}{sup +}+n{sub Cl{sub 2}{sup +}}) obtained with a Langmuir probe. Both n{sub Cl{sub 2}{sup +}} and n{sub i}{sup +} doubled with increasing rf power from 8 to {approximately}55 W in the capacitively coupled (dim) mode. Above the transition from a capacitively to inductively coupled (bright-mode) plasma at {approximately}85{plus_minus}35 W, n{sub Cl{sub 2}{sup +}} decayed with rf power while n{sub i}{sup +} continued to increase. Consequently, Cl{sub 2}{sup +} is the dominant ion in dim-mode operation and Cl{sup +} is the dominant ion in bright-mode operation, at n{sub i}{sup +}{ge}6{times}10{sup 10} cm{sup {minus}3}. With the plasma operating in the reaction ion etch (RIE) mode (the stage powered at 14.56 MHz, and no TCP power) n{sub Cl{sub 2}{sup +}} tracked n{sub i}{sup +} over the entire range of powers (2{endash}150 W). Thus, Cl{sub 2}{sup +} is the dominant ion during capacitively coupled RIE operation. {copyright}more » {ital 1999 American Institute of Physics.}« less

Authors:
; ; ;  [1];  [2]
  1. Bell Laboratories, Lucent Technologies, Murray Hill, New Jersey 07974 (United States)
  2. Department of Applied Physics, Columbia Radiation Laboratory, Columbia University, New York, New York 10027 (United States)
Publication Date:
OSTI Identifier:
321949
Resource Type:
Journal Article
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 74; Journal Issue: 12; Other Information: PBD: Mar 1999
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; CHLORINE; PLASMA DENSITY; PLASMA DIAGNOSTICS; LANGEVIN EQUATION; CHLORINE IONS; FLUORESCENCE; ETCHING; MICROELECTRONICS; ION DENSITY

Citation Formats

Malyshev, M V, Fuller, N C, Bogart, K H, Donnelly, V M, and Herman, I P. Laser-induced fluorescence and Langmuir probe determination of Cl{sub 2}{sup +} and Cl{sup +} absolute densities in transformer-coupled chlorine plasmas. United States: N. p., 1999. Web. doi:10.1063/1.123648.
Malyshev, M V, Fuller, N C, Bogart, K H, Donnelly, V M, & Herman, I P. Laser-induced fluorescence and Langmuir probe determination of Cl{sub 2}{sup +} and Cl{sup +} absolute densities in transformer-coupled chlorine plasmas. United States. doi:10.1063/1.123648.
Malyshev, M V, Fuller, N C, Bogart, K H, Donnelly, V M, and Herman, I P. Mon . "Laser-induced fluorescence and Langmuir probe determination of Cl{sub 2}{sup +} and Cl{sup +} absolute densities in transformer-coupled chlorine plasmas". United States. doi:10.1063/1.123648.
@article{osti_321949,
title = {Laser-induced fluorescence and Langmuir probe determination of Cl{sub 2}{sup +} and Cl{sup +} absolute densities in transformer-coupled chlorine plasmas},
author = {Malyshev, M V and Fuller, N C and Bogart, K H and Donnelly, V M and Herman, I P},
abstractNote = {Laser induced fluorescence detection of Cl{sub 2}{sup +} has been used to track their relative concentration in a high-density inductively (transformer) coupled (TCP) 10 mTorr chlorine plasma as a function of the 13.56 MHz radio frequency (rf) power. This relative Cl{sub 2}{sup +} number density was compared to the total absolute positive ion density (n{sub i}{sup +}=n{sub Cl}{sup +}+n{sub Cl{sub 2}{sup +}}) obtained with a Langmuir probe. Both n{sub Cl{sub 2}{sup +}} and n{sub i}{sup +} doubled with increasing rf power from 8 to {approximately}55 W in the capacitively coupled (dim) mode. Above the transition from a capacitively to inductively coupled (bright-mode) plasma at {approximately}85{plus_minus}35 W, n{sub Cl{sub 2}{sup +}} decayed with rf power while n{sub i}{sup +} continued to increase. Consequently, Cl{sub 2}{sup +} is the dominant ion in dim-mode operation and Cl{sup +} is the dominant ion in bright-mode operation, at n{sub i}{sup +}{ge}6{times}10{sup 10} cm{sup {minus}3}. With the plasma operating in the reaction ion etch (RIE) mode (the stage powered at 14.56 MHz, and no TCP power) n{sub Cl{sub 2}{sup +}} tracked n{sub i}{sup +} over the entire range of powers (2{endash}150 W). Thus, Cl{sub 2}{sup +} is the dominant ion during capacitively coupled RIE operation. {copyright} {ital 1999 American Institute of Physics.}},
doi = {10.1063/1.123648},
journal = {Applied Physics Letters},
number = 12,
volume = 74,
place = {United States},
year = {1999},
month = {3}
}