1,479 research outputs found
SIMS RSFs in silicon for positive secondary ions with O2+ 1keV at 63° incidence sputtering beam and Zalar rotation.
No full textThe RSFs depend on each SIMS instrument and are affected by the particular analytical conditions used to collect the data. In particular some artifacts occur by sputtering silicon with 1keV O2+ at 63° incidence. The surface topography evolves These artifacts have a big impact on the RFSs for any analyte elements in silicon because of a systematic count rates increase of all reference isotope matrix signals. 25 RSFs are here obtained on ion implanted reference materials following the ISO standard 18114:2003, with and without the Zalar rotation installed on the Cameca SC-ultra. These data are eventually compared with the corresponding RSFs published in the 80-90’s obtained by ims3f and 4f instruments
Boron Ultra Low Energy SIMS Depth Profiling Improved by Rotating Stage
No full textOptimization of oblique incidence ultra low energy O2+ SIMS analysis of ultra shallow boron distributions has been investigated varying the atmosphere in the analysis chamber (ultra high vacuum or oxygen flooding) and evaluating the effect of a rotating stage allowing a 20 rpm rotation during the analysis. The impact of the different analytical approaches to the ripple formation on the crater bottom has been investigated on a boron delta doped silicon sample by AFM analysis. The combined use of a 0.5 keV O2+ beam at 68° of incidence with oxygen flooding and stage rotation of 20 rpm gave a decay length of 2.0 nm/decade at 60 nm depth without any appreciable detection of variation of sputtering rate
D-SIMS and ToF-SIMS quantitative depth profiles comparison on ultra thin oxynitrides
No full textTo realise gate dielectrics in the present ULSI technology ultra thin oxynitrides are used. Nitrogen quantitative depth profiles are mandatory to characterise this material.
Depth resolution is the key analytical parameter to obtain useful ultra thin oxides characterisation. To improve this resolution very low primary ion impact energy is required. In the present paper, we compare quantitative depth profiles carried out by dynamic-SIMS and ToF-SIMS, respectively.
Dynamic-SIMS analyses have been performed using a Cameca 4-f and the new Cameca Sc-Ultra 300 instrument. Different impact energies and incidence angles were used in combination with MCs+ ion monitoring.
The D-SIMS profiles at keV and sub keV primary beam impact energies, are discussed and compared with ToF-SIMS data obtained using a IONTOF IV instrument
ToF-SIMS and AFM studies of low-k dielectric etching in fluorocarbon plasmas
No full textSurface modifications and etching mechanisms of several nanoporous low-k dielectrics (spin-on and PECVD) using fluorocarbon plasmas have been investigated by ToF-SIMS and AFM and compared with those of SiO2. The results show a fluoropolymer film growing on the materials using highly polymerizing discharges (C4F8). The fluoropolymers are converted into fluoroether-like compounds upon etching low-porosity dielectrics in ion-rich C4F8/90% Ar plasmas. These layers mitigate the influx of plasma species and inhibit the etching rate. No surface roughness develops for
these conditions, keeping the plasma/material interaction regime stationary. On the other hand, the surface coverage by fluoroethers is reduced when the porosity exceeds a given threshold. Consequently, direct plasma/dielectric interactions including ion bombardment take place, causing an increase of the etching rate, surface roughening and severe modifications of the pristine dielectric
Comparison between the SIMS and MEIS techniques for the characterization of ultra shallow arsenic implants
No full textSIMS and medium energy ion scattering (MEIS) have been applied to the characterization of ultra shallow distribution of arsenic in silicon obtained by ion implantation at 1 and 3 keV and successive annealing at low temperature (lower than 700 °C). In case of heavy elements in light matrices, the MEIS ultimate depth resolution and its ability to obtain quantitative results from first principles result in a good reference for SIMS depth profiling. The comparison of the results obtained by the two techniques allows to discriminate among different SIMS quantification processes in order to individuate the best in terms of accuracy in the initial transient width and at the SiO2–silicon interface: the simple normalization of 28Si75As- curve to the average of 28Si2- results in the best agreement between SIMS and MEIS in the surface region. Moreover SIMS profile of the 3 keV as implanted sample resulted 1.9 nm shallower than correspondent MEIS profiles whereas samples annealed at either 650 °C or 700 °C for 10 s show a good alignment of the As segregation peak at the SiO2/Si interface. The sample annealed at 550 °C for 200 s shows a reduced shift between SIMS and MEIS measured As peak: a possible effect of the residual amorphous layer on the sputtering rate is pointed out as responsible of these different shifts
Visualisation of amphetamine contamination in fingerprints using tof-sims technique
No full textTime-of-flight secondary ion mass spectrometry (TOF-SIMS) was applied to detect traces of amphetamine on fingerprints. In the present study, three different lift tapes and latent powder fingerprints were tested. The obtained results show that it is possible to identify traces of a drug as well as its distribution over the tested fingerprint after its transfer from the primary base onto an adhesive lifter (secondary base). Moreover, images obtained by the TOF-SIMS technique enable the observation of very small areas of the analysed fingerprint as well as the identification of micro-objects (residues of a contaminant) that were left on the fingerprint. The use of the black latent fingerprint powder did not interfere with the TOF-SIMS analysis, which makes it possible to effectively use this technique to study the traces of substances on the revealed fingerprints.ChemE/Advanced Soft Matte
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