Surface modification of GaAs(110) by low-energy ion irradiation

Journal Article · Wed Nov 15 04:00:00 EST 1995 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.52.14086· OSTI ID:130716

Gnaser, H; Heinz, B; Bock, W; Oechsner, H ^[1]

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1. Fachbereich Physik and Institut fuer Oberflaechen- und Schichtanalytik, Universitaet Kaiserslautern, D-67663 Kaiserslautern (Germany)

The GaAs(110) surface was exposed to normal-incidence Ar{sup +} ion bombardment at energies ranging from 200 eV to 3 keV. The structural, electronic, and compositional modifications induced were monitored by low-energy electron diffraction, electron energy-loss spectroscopy (EELS), and by Auger-electron spectroscopy for different flux densities, accumulated fluences, and specimen temperatures. The fluences necessary for the amorphization of the near-surface region at room temperature amount to some 1{times}10{sup 15} Ar{sup +}/cm{sup 2} and increase both with decreasing flux density and with decreasing impact energy, the latter effect being very pronounced below 1 keV. The alterations of the electronic states as inferred from EELS exhibit a similar fluence dependence but are less sensitive to the bombardment energy. Prolonged ion irradiation causes an As depletion of the surface which saturates at fluences {ge}1{times}10{sup 16} Ar{sup +}/cm{sup 2}, again dependent on the impact energy and flux density. The steady-state Ga/As surface concentration ratio ({ital c}{sub Ga}/{ital c}{sub As}){sub {infinity}} is 1.25 (relative to the bulk composition) at 200 eV and {ital increases} to {similar_to}1.45 at 3 keV. These surface composition changes are {ital reduced} for ion bombardment at elevated specimen temperatures and almost no variations are observed with the sample held at 730 K.

• OSTI ID: 130716
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 19 Vol. 52; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
AMBIENT TEMPERATURE
AMORPHOUS STATE
ARGON IONS
AUGER ELECTRON SPECTROSCOPY
ELECTRON DIFFRACTION
ELECTRON SPECTROSCOPY
ENERGY-LOSS SPECTROSCOPY
EPITAXY
EV RANGE 100-1000
GALLIUM ARSENIDES
ION BEAMS
IRRADIATION
KEV RANGE 01-10
RADIATION EFFECTS
RADIATION FLUX
STOICHIOMETRY
SURFACE IONIZATION
SURFACE PROPERTIES
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0400-1000 K