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Title: Absolute intensities of the vacuum ultraviolet spectra in oxide etch plasma processing discharges

Abstract

In this paper, the authors report the absolute intensities of ultraviolet light between 4.9 eV and 24 eV ( 250 nm to 50 mn ) striking a silicon wafer in a number of oxide-etch processing discharges. The emphasis is on photons with energies greater than 8.8 eV, which have enough energy to damage SiO{sub 2}. These discharges were in an inductively-driven Gaseous Electronics Conference reference cell which had been modified to more closely resemble commercial etching tools. Comparisons of measurements made through a side port in the cell and through a hole in the wafer indicate that the VUV light in these discharges is strongly trapped. For the pure halocarbon gases examined in these experiments (C{sub 2}F{sub 6}, CHF{sub 3}, C{sub 4}F{sub 8}), the fluxes of VUV photons to the wafer varied from 1 x 10{sup 15} to 3 x 10{sup 15} photons/cm{sup 2} sec or equivalently from 1.5 to 5 mW/cm{sup 2}. These measurements imply that 0.1% to 0.3% of the rf source power to these discharges ends up hitting the wafer as VUV photons for the typical 20 mT, 200 W rf discharges. For typical ashing discharges containing pure oxygen, the VUV intensities are slightly higher--about 8 mW/cm{supmore » 2} . As argon or hydrogen diluents are added to the fluorocarbon gases, the VUV intensities increase dramatically, with a 10/10/10 mixture of Ar/C{sub 2}F{sub 6}/H{sub 2} yielding VUV fluxes on the wafer 26 mW/cm{sup 2} and pure argon discharges yielding 52 mW/cm{sup 2} . Adding an rf bias to the wafer had only a small effect on the VUV observed through a side-port of the GEC cell.« less

Authors:
; ; ; ;
Publication Date:
Research Org.:
Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
755585
Report Number(s):
SAND2000-1097J
TRN: AH200021%%350
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Journal Article
Journal Name:
Journal of Vacuum Science and Technology
Additional Journal Information:
Other Information: Submitted to Journal of Vacuum Science and Technology; PBD: 1 May 2000
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 42 ENGINEERING; MANUFACTURING; INTEGRATED CIRCUITS; PLASMA DIAGNOSTICS; FAR ULTRAVIOLET RADIATION; ULTRAVIOLET SPECTRA; ETCHING

Citation Formats

WOODWORTH,JOSEPH R., RILEY,MERLE E., AMATUCCI,VINCENT A., HAMILTON,THOMAS W., and ARAGON,BEN P. Absolute intensities of the vacuum ultraviolet spectra in oxide etch plasma processing discharges. United States: N. p., 2000. Web.
WOODWORTH,JOSEPH R., RILEY,MERLE E., AMATUCCI,VINCENT A., HAMILTON,THOMAS W., & ARAGON,BEN P. Absolute intensities of the vacuum ultraviolet spectra in oxide etch plasma processing discharges. United States.
WOODWORTH,JOSEPH R., RILEY,MERLE E., AMATUCCI,VINCENT A., HAMILTON,THOMAS W., and ARAGON,BEN P. Mon . "Absolute intensities of the vacuum ultraviolet spectra in oxide etch plasma processing discharges". United States. https://www.osti.gov/servlets/purl/755585.
@article{osti_755585,
title = {Absolute intensities of the vacuum ultraviolet spectra in oxide etch plasma processing discharges},
author = {WOODWORTH,JOSEPH R. and RILEY,MERLE E. and AMATUCCI,VINCENT A. and HAMILTON,THOMAS W. and ARAGON,BEN P.},
abstractNote = {In this paper, the authors report the absolute intensities of ultraviolet light between 4.9 eV and 24 eV ( 250 nm to 50 mn ) striking a silicon wafer in a number of oxide-etch processing discharges. The emphasis is on photons with energies greater than 8.8 eV, which have enough energy to damage SiO{sub 2}. These discharges were in an inductively-driven Gaseous Electronics Conference reference cell which had been modified to more closely resemble commercial etching tools. Comparisons of measurements made through a side port in the cell and through a hole in the wafer indicate that the VUV light in these discharges is strongly trapped. For the pure halocarbon gases examined in these experiments (C{sub 2}F{sub 6}, CHF{sub 3}, C{sub 4}F{sub 8}), the fluxes of VUV photons to the wafer varied from 1 x 10{sup 15} to 3 x 10{sup 15} photons/cm{sup 2} sec or equivalently from 1.5 to 5 mW/cm{sup 2}. These measurements imply that 0.1% to 0.3% of the rf source power to these discharges ends up hitting the wafer as VUV photons for the typical 20 mT, 200 W rf discharges. For typical ashing discharges containing pure oxygen, the VUV intensities are slightly higher--about 8 mW/cm{sup 2} . As argon or hydrogen diluents are added to the fluorocarbon gases, the VUV intensities increase dramatically, with a 10/10/10 mixture of Ar/C{sub 2}F{sub 6}/H{sub 2} yielding VUV fluxes on the wafer 26 mW/cm{sup 2} and pure argon discharges yielding 52 mW/cm{sup 2} . Adding an rf bias to the wafer had only a small effect on the VUV observed through a side-port of the GEC cell.},
doi = {},
journal = {Journal of Vacuum Science and Technology},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {5}
}