Auger-electron emission induced by Ar/sup +/ impact on silicides

Journal Article · Thu Dec 15 04:00:00 EST 1988 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.38.13282· OSTI ID:6551230

Valeri, S; Tonini, R; Ottaviani, G

Impact of ions of several kilo-electron-volts (keV) with solids produces inner-shell excitations. The consequent decay results in the emission of Auger electrons whose spectra differ considerably from electrons or x-ray-excited spectra. Si (L/sub 23/-derived) Auger emission, induced by Ar/sup +/ bombardment in pure Si and silicides of different metals (Cr,Ni,Pt) and stoichiometry (from NiSi/sub 2/ to Ni/sub 3/Si), has been studied by varying both the energy of the primary ions (in the 1--5-keV range) and the takeoff angle (from grazing to normal geometry). We separated the background of inelastic scattered electrons from the Auger electrons, and in a further step the contributions to the spectra coming from deexcitation inside and outside the solid. The portion of the Auger emission which originates from sputtered atoms (''atomic spectrum'') was found to depend on the target composition and takeoff angle, being larger in metal-rich silicides and at grazing geometry. The parents of ''atomic'' Auger electrons were found to be mainly neutral and excited sputtered atoms in Si and Si-rich silicides, while in metal-rich silicides there is a dominant contribution from sputtered ions. These results have been discussed in terms of the inner-shell ionization mechanism and the in-depth distribution of exciting collisions. The ''atomic'' spectral shape dependencies on ion energy and takeoff angle have been interpreted in terms of the Doppler shift imparted to the Auger-electron velocity by an anisotropic jet of high-energy parent atoms.

• Research Organization: Dipartimento di Fisica Universita di Modena, via Campi 213/A, I-41100 Modena, Italy
• OSTI ID: 6551230
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:18; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

656003* -- Condensed Matter Physics-- Interactions between Beams & Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ARGON IONS
AUGER EFFECT
CHARGED PARTICLES
CHROMIUM COMPOUNDS
CHROMIUM SILICIDES
COLLISIONS
ELECTRON SPECTRA
ELEMENTS
EMISSION
ENERGY RANGE
INCIDENCE ANGLE
ION COLLISIONS
IONS
KEV RANGE
KEV RANGE 01-10
NICKEL COMPOUNDS
NICKEL SILICIDES
PLATINUM COMPOUNDS
PLATINUM SILICIDES
SECONDARY EMISSION
SEMIMETALS
SILICIDES
SILICON
SILICON COMPOUNDS
SPECTRA
TRANSITION ELEMENT COMPOUNDS