Experimental studies of ionization processes in sputtering of GaAs

doi:10.1016/0039-6028(95)00995-7

Surface Science

Volume 348, Issues 1–2, 1 March 1996, Pages 100-104

https://doi.org/10.1016/0039-6028(95)00995-7 Get rights and content

Abstract

Ionization processes in GaAs have been analyzed using primary ion beams (He⁺, Xe⁺) and primary neutral beams (He⁰, Xe⁰) with energies between 500 eV and 4 keV. The ionization probability of Ga⁺ has been found to be independent of bombarding conditions and equal to 0.04. The As⁺ and As⁻ ionization yields depend very strongly on the bombarding conditions, and are the same for both ion and neutral particle bombardments. The absolute ionization probability of As⁺ for Xe impact changes from 8 × 10⁻⁷ to 2 × 10⁻⁵ when the primary beam energy changes from 500 eV to 4 keV. Taking these experimental results into account, the most probable ionization process for As is suggested and discussed.

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Mass and energy distribution of positively and negatively charged small ${Ga}_{x} {As}_{y}$ cluster ions consisting of up to six atoms sputtered from a GaAs(100) surface after 150 keV Ar⁺ ion bombardment are reported. Positively charged ions contain a larger fraction of Ga atoms while negatively charged ions are rich in As. Measured energy distributions display a maximum at low kinetic energies of a few eV followed by a steep decrease with increasing energy which is more pronounced for larger ions.
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Experimental and simulated energy distributions of Ga⁺ and In⁺ secondary ions produced by 4 keV Ne⁺, Ar⁺ and Kr⁺ bombardment of the A^IIIB^V semiconductors (GaP, GaAs, GaSb, InP, InAs and InSb) are reported. The measurements were carried out for a wide range of initial energy (up to 1000 eV) in a small solid angle along the surface normal, without applying electric field to extract the ions into the mass-energy analyser. It is shown that the energy spectra are complex, with evident high-energy hump, whose relative intensity increases with the mass of the second component (P, As, Sb) of the compound. The Sigmund–Thompson distribution cannot fit reliably these data, and a satisfactory approximation of the measured spectra was obtained with a sum of two decaying exponential functions to describe the contribution of both, the isotropic linear collision cascades and the outward knock-on atoms. The experimental results are compared with simulations based on the MARLOWE computer code.
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Surface Science

Abstract

References (11)

Nucl. Instrum. Meth. Phys. Res. B

Surf. Sci.

Energy dependence of the yields of ion-induced sputtering of monatomic solids

J. Appl. Phys.

Appl. Phys. Lett.

Appl. Phys. Lett.

Spectrochim. Acta B

Cited by (9)

Mass and energy distribution of negatively and positively charged small cluster ions sputtered from GaAs(100) by 150 keV Ar<sup>+</sup> bombardment

Energy distributions of Ga<sup>+</sup> and In<sup>+</sup> secondary ions sputtered from A<sup>III</sup>B<sup>V</sup> compound semiconductors by noble gas ions: Mass-dependence of the high-energy yield on the second component (P, As, Sb) of the compounds

Recoil-ion fractions in collisions of keV Ar<sup>+</sup> and Kr<sup>+</sup> ions with clean and adsorbate covered GaAs(1 1 0) surfaces

Interaction of slow, very highly charged ions with surfaces

Production of energetic electrons in low-energy collision cascades in solids

Surface analysis by laser ionization