Characterization of high-pressure capacitively coupled hydrogen plasmas

Journal Article · Thu Nov 01 00:00:00 EDT 2007 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2809345· OSTI ID:21064425

Nunomura, S; Kondo, M ^[1]

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1. Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568 (Japan)

Capacitively coupled very-high-frequency hydrogen plasmas have been systematically diagnosed in a wide range of a gas pressure from 5 mTorr to 10 Torr. The plasma parameters, ion species, and ion energy distributions (IEDs) are measured using a Langmuir probe, optical emission spectroscopy, and energy filtered mass spectrometer. The measurement results show that the ion species in a hydrogen plasma is determined from ionization channels and subsequent ion-molecule reactions. The ions are dominated by H{sub 2}{sup +} at a less-collisional condition of < or approx. 20 mTorr, whereas those are dominated by H{sub 3}{sup +} at a collisional condition of > or approx. 20 mTorr. The IED is determined by both the sheath potential drop and ion-neutral collisions in the plasma sheath. The IED is broadened for a collisional sheath at > or approx. 0.3 Torr and the ion bombardment energy is lowered. For high-pressure discharge operated at {approx_equal}10 Torr, plasmas are characterized by a low electron temperature of {approx_equal}0.8 eV and a low ion bombardment energy of < or approx. 15 eV.

• OSTI ID: 21064425
• Journal Information: Journal of Applied Physics, Vol. 102, Issue 9; Other Information: DOI: 10.1063/1.2809345; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ELECTRIC DISCHARGES
ELECTRON TEMPERATURE
EMISSION SPECTROSCOPY
ENERGY SPECTRA
EV RANGE 01-10
EV RANGE 10-100
HYDROGEN
HYDROGEN IONS 2 PLUS
HYDROGEN IONS 3 PLUS
ION BEAMS
ION TEMPERATURE
ION-MOLECULE COLLISIONS
IONIZATION
LANGMUIR PROBE
MASS SPECTROMETERS
MASS SPECTROSCOPY
PLASMA
PLASMA PRESSURE
PLASMA SHEATH
PRESSURE RANGE PA