E-H mode transition in low-pressure inductively coupled nitrogen-argon and oxygen-argon plasmas

Journal Article · Wed Jun 01 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3587156· OSTI ID:21538395

Lee, Young Wook; Lee, Hye Lan; Chung, T H ^[1]

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1. Department of Physics, Dong-A University, Busan 604-714 (Korea, Republic of)

This work investigates the characteristics of the E-H mode transition in low-pressure inductively coupled N{sub 2}-Ar and O{sub 2}-Ar discharges using rf-compensated Langmuir probe measurements and optical emission spectroscopy (OES). As the ICP power increases, the emission intensities from plasma species, the electron density, the electron temperature, and the plasma potential exhibit sudden changes. The Ar content in the gas mixture and total gas pressure have been varied in an attempt to fully characterize the plasma parameters. With these control parameters varying, the changes of the transition threshold power and the electron energy distribution function (EEDF) are explored. In N{sub 2}-Ar and O{sub 2}-Ar discharges at low-pressures of several millitorr, the transition thresholds are observed to decrease with Ar content and pressure. It is observed that in N{sub 2}-Ar plasmas during the transition, the shape of the EEDF changes from an unusual distribution with a flat hole near the electron energy of 3 eV in the E mode to a Maxwellian distribution in the H mode. However, in O{sub 2} -Ar plasmas, the EEDFs in the E mode at low Ar contents show roughly bi-Maxwellian distributions, while the EEDFs in the H mode are observed to be nearly Maxwellian. In the E and H modes of O{sub 2}-Ar discharges, the dissociation fraction of O{sub 2} molecules is estimated using optical emission actinometry. During the E-H mode transition, the dissociation fraction of molecules is also enhanced.

• OSTI ID: 21538395
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 11 Vol. 109; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ARGON
CONFINEMENT
DEUTERIUM
DEW POINT
DISSOCIATION
ELECTRIC DISCHARGES
ELECTRIC POTENTIAL
ELECTRIC PROBES
ELECTRON DENSITY
ELECTRON TEMPERATURE
ELEMENTS
EMISSION SPECTROSCOPY
ENERGY SPECTRA
FLUIDS
GASES
H-MODE PLASMA CONFINEMENT
HUMIDITY
HYDROGEN ISOTOPES
INSTABILITY
ION TEMPERATURE
ISOTOPES
LANGMUIR PROBE
LIGHT NUCLEI
MAGNETIC CONFINEMENT
MOISTURE
NITROGEN
NONMETALS
NUCLEI
ODD-ODD NUCLEI
OXYGEN
PHYSICAL PROPERTIES
PLASMA
PLASMA CONFINEMENT
PLASMA DENSITY
PLASMA INSTABILITY
PLASMA POTENTIAL
PROBES
RARE GASES
SPECTRA
SPECTROSCOPY
STABLE ISOTOPES
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE