Imaging G‐SIMS: a novel bismuth‐manganese source emitter

Abstract

G-SIMS (gentle-SIMS) is a powerful method that considerably simplifies complex static secondary ion mass spectrometry (SSIMS) analysis of organics at surfaces. G-SIMS uses two primary ion beams that generate high and low fragmentation conditions at the surface. This allows an extrapolation to equivalent experimental conditions with very low fragmentation. Consequently, the spectra are less complex, contain more structural information and are simpler to interpret. In general, G-SIMS spectra more closely resemble electron ionisation mass spectra than SSIMS spectra. A barrier for the wider uptake of G-SIMS is the requirement for two ion beams producing suitably different fragmentation conditions and the need for their spatial registration (spatial alignment) at the surface, which is especially important for heterogeneous samples. The most popular source is the liquid metal ion source (LMIS), which is now sold with almost every new time-of-flight (TOF)-SIMS instrument. Here, we have developed a novel bismuth-manganese emitter (the 'G-tip') for the popular LMISs. This simplifies the alignment and gives excellent G-SIMS imaging and spectroscopy without significantly compromising the bismuth cluster ion beam performance.

Time of flight secondary ion mass spectrometric determination of molecular weight distributions of low polydispersity poly(dimethyl siloxane) with polyatomic primary ions

“…Their work resulted in the development of an algorithm to reduce the number of fragment peaks in a SIMS spectrum (G-SIMS) and helps elucidate the characteristic molecular peak. This algorithm requires the acquisition of two mass spectra with different primary ion sources, however, cluster ions are not appropriate for this analysis due to differences in their sputtering mechanism [19,24]. The current work attempts to elucidate differences of monatomic and polyatomic primary ions for the study of high mass molecular weight distributions.…”

Surface Analysis of Organic Materials with Polyatomic Primary Ion Sources

“…Nowadays, the G-SIMS process can be integrated into the software and hardware of certain instrument designs. 180 An example representing the utility of G-SIMS for analysis of polymers is shown in Figure 4.16, which shows the representative positive ion SIMS spectrum ( Fig. 4.16a) and the corresponding G-SIMS spectrum (Fig.…”

G‐SIMS: relative effectiveness of different monatomic primary ion source combinations

“…2 have been generated. This is the same as the data in Gilmore and Seah1 but with the data for Mn and Bi7 added, together with error bars for each point from the original repeatability data.…”

“…If the sample is not very homogeneous and the beam positions are not well aligned, the measured G‐SIMS spectrum becomes less repeatable and less reliable. Recent developments of a binary Mn‐Bi emitter have overcome this alignment problem so that the two beams align within their spatial resolution 7. This new source provides added data to that originally published1 for the values of β for polystyrene.…”