ERDA with 2600 keV 4He incident ions and
dE-E telescope for detection of H and D at a recoil angle of 30°. Both cross-sections are non-Rutherford.
Dots: Experimental data; Lines: SIMNRA simulation.
Multiple and plural scattering
500 keV 4He backscattered from 100 nm Au on Si,
scattering angle 165°. The background below the low energy edge of
Au is due to plural large angle scattering, which is approximated in
the dual scattering approximation by SIMNRA. The single scattering
approximation, which is normaly used, fits the experimental data
poorly. From [Eckstein99].
Surface roughness
1.5 MeV 4He backscattered from a rough
Ni-film on carbon, scattering angle 165°. Mean Ni-film thickness
240 nm, FWHM of roughness 23 nm. Dots: Experimental data;
Dashed line: SIMNRA simulation assuming a smooth Ni film; Solid line: SIMNRA simulation assuming a rough Ni film.
From [Mayer02].
2.0 MeV 4He backscattered from a rough
oxidised Al-film on carbon, scattering angle 165°. The initial film
was strongly eroded by plasma exposure, and some Ni was deposited.
Dots: Experimental data; Solid line: SIMNRA simulation with a mean
film thickness of 184 nm and a roughness FWHM of 176 nm. Such extreme
roughnesses cannot be described by smooth layers or diffusion profiles.
From [Mayer02].
2.5 MeV protons backscattered from a 3.5 µm thick tungsten film
on a rough carbon substrate, scattering angle 165°. The mean
roughness of the carbon substrate was 8.2 µm.
Dots: Experimental data; Dashed line: SIMNRA simulation assuming a smooth substrate;
Solid line: SIMNRA simulation assuming a rough substrate.
From [Mayer02].
Structured layers
Backscattering of 1500 keV 4He ions from a silicon grating on
top of a tantalum interlayer on top of silicon substrate.
Top: Focused ion beam cross-section through the sample structure.
Middle: Schematic representation of
the measurement geometry parallel to the silicon grating structure, scattering angle 165°. Bottom: Experimental spectrum (black dots) and simulation
(red line) with SIMNRA 7. From [Langhuth11], [Mayer16a].
Porous layers
Top: Scanning electron micrograph of a porous V2O5 layer.
Bottom: Backscattering spectrum of the porous V2O5 layer on silicon substrate using 1500 keV 4He
ions at a scattering angle of 165°. Dots: Experimental data; Solid line: Computer simulation with SIMNRA 7 assuming a porous layer with 40% pore fraction
and a pore diameter of 31 nm; Dashed line: Computer simulation assuming a dense layer. From [Mayer14].
Pile-up simulation
Backscattering spectrum of 2 MeV 4He on bulk gold with pile-up, measured
with a Canberra DSP 9660, PUR on, 6% dead time.
Dots: Experimental data; Dashed line: SIMNRA simulation without pile-up; Solid line: SIMNRA simulation with pile-up.
