In situ measurement of surface potential developed on MgO thin film surface under ion irradiation using ion scattering spectroscopy

Journal Article · Sun Nov 15 00:00:00 EST 2009 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3259428· OSTI ID:21361943

Nagatomi, T; Kuwayama, T; Takai, Y ^[1]; Yoshino, K ^[1]; Morita, Y; Kitagawa, M ^[2]; Nishitani, M ^[3]

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1. Department of Materials and Life Science, Graduate School of Engineering, Osaka University, Suita, Osaka 565-0871 (Japan)
2. Panasonic AVC Networks Company, Panasonic Corporation, Ibaraki, Osaka 567-0026 (Japan)
3. Panasonic Corporation, Moriguchi, Osaka 570-8501 (Japan)

The application of ion scattering spectroscopy (ISS) to the in situ measurement of the surface potential developed on an insulator surface under positive ion irradiation was investigated. The ISS spectra measured for a MgO film of 600 nm thickness on a Si substrate by the irradiation of 950 eV He{sup +} ions revealed that the surface is positively charged by approximately 180 V. For accurate measurement of the surface potential, a correction to take into account the angular deflection of primary ions induced by the high surface potential is required. The dependence of the surface potential on the sample temperature revealed that no charging is induced above 700 deg. C, indicating that accumulated charges can be removed by heating to 700 deg. C. From the measurement of the ion-induced secondary electron yield using a collector electrode located in front of the sample surface, the surface potential and ion-induced secondary electron yield were found to be strongly affected by the experimental setup. Secondary electrons produced by the impact of slow positive secondary ions, the maximum energy of which corresponds to the surface potential, play an important role when the bias voltage applied to the collector electrode is positively high for the present experimental setup. The surface potential developed on the surface of MgO films of 600 and 200 nm thickness was measured in situ, revealing that the amount of accumulated charges and the time required to attain the steady state of charging are slightly dependent on the beam current of primary ions and strongly dependent on the thickness of the MgO film. The present results confirmed that the application of ISS has high potential for investigating charging phenomena and the secondary electron emission from insulator surfaces under positive ion irradiation.

• OSTI ID: 21361943
• Journal Information: Journal of Applied Physics, Vol. 106, Issue 10; Other Information: DOI: 10.1063/1.3259428; (c) 2009 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
BEAM CURRENTS
CATIONS
ELECTRIC POTENTIAL
ELECTRODES
ELECTRON EMISSION
ELECTRONS
EV RANGE 100-1000
HEATING
HELIUM IONS
ION BEAMS
IRRADIATION
MAGNESIUM OXIDES
SCATTERING
SPECTRA
SPECTROSCOPY
STEADY-STATE CONDITIONS
SUBSTRATES
SURFACE POTENTIAL
THIN FILMS
ALKALINE EARTH METAL COMPOUNDS
BEAMS
CHALCOGENIDES
CHARGED PARTICLES
CURRENTS
ELEMENTARY PARTICLES
EMISSION
ENERGY RANGE
EV RANGE
FERMIONS
FILMS
IONS
LEPTONS
MAGNESIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POTENTIALS