Aberration-corrected focused ion beam for time-of-flight secondary neutral mass spectrometry

Abstract

A chromatic and spherical aberration corrector with liquid Ga ion metal source was developed. The aberration corrector reduced the ion probe diameter to ~1.5 times smaller for the 69 Ga + beam in aberration correction mode compared with the corrector in non-aberration correction mode. The probe current at a given probe size is approximately two times larger in aberration correction mode than in non-aberration correction mode. The aberration-corrected focused ion beam yields higher lateral resolutions and higher sensitivities with lower acceleration voltage for the same acquisition time down to 10 nm with a current of 1 pA.

In Situ Helium Isotope Microimaging of Meteorites

“…The primary beam was pulsed to widths of 200–400 ns. The beam was corrected for spherical aberration by the aberration-correcting optics ,, and focused to 2 μm on the sample surface, which is defined by the 16–84% criterion using line scans . The angle of incidence of the primary beam on the sample was set to 55°, which was formed by the optical axis of the primary beam and the sample surface.…”

“…We developed a secondary neutral mass spectrometry technique using laser postionization and a focused ion beam to examine the micrometer- and nanometer-scale noble gas distributions. ,− The lateral resolution of the 4 He measurements was ∼3 μm and the detection limit was 3 × 10 18 cm –3 , which is close to the highest 4 He concentration observed in meteorites. If the 4 He distribution in meteorites is homogeneous, then the concentration is below the detection limit, and it is difficult to observe 4 He there.…”

Visualization of DNA Replication in Single Chromosome by Stable Isotope Labeling

“…Ion-induced SE images were obtained with gallium (Ga) focused ion beam current of 3 pA and an acceleration voltage of 20kV (Ebata et al, 2012). The secondary neutral mass spectrometer also enabled analysis with a high lateral resolution of up to 10 nm and high mass resolution of 10 6 for full width half maximum (Bajo et al, 2016(Bajo et al, , 2019Ebata et al, 2012;Nagata et al, 2019;Tonotani et al, 2016;Yurimoto et al, 2016). In this regard, the primary ion beam was focused to a diameter of 100 nm at a current of 400 pA with an acceleration voltage of 20 kV (Nagata et al, 2019).…”

“…The secondary neutral mass spectrometer also enabled analysis with a high lateral resolution of up to 10 nm and high mass resolution of 10 6 for full width half maximum (Bajo et al, 2016(Bajo et al, , 2019Ebata et al, 2012;Nagata et al, 2019;Tonotani et al, 2016;Yurimoto et al, 2016). In this regard, the primary ion beam was focused to a diameter of 100 nm at a current of 400 pA with an acceleration voltage of 20 kV (Nagata et al, 2019). The primary beam scanned a 19.2 × 33.7 µm 2 area at an incident angle of 35˚ from the sample surface to acquire a 300 × 300 pixel ion imaging.…”

Metal-assisted chemical etching of high throughput, high aspect ratio critical-angle transmission gratings with vertical and smooth sidewalls

“…Specifically, the diffraction efficiency can be as high as 50% and the bandwidth is very wide; the mass is very low; when used, it is basically perpendicular to the incident light and the required grating area is small; it has low requirements for grating flatness and alignment; it is insensitive to polarization; and by varying the geometrical dimensions of the grating and incident angle, X-rays can be blazed in higher diffraction orders to increase the spectral resolving power. Based on these advantages, the CAT grating has considerable potential application in many fields such as X-ray spectroscopic telescopes in astronomy, 4,5) plasma diagnosis in laser inertial confinement fusion, 6,7) X-ray phase contrast imaging, [8][9][10][11] ultraviolet filtration, 12,13) neutral mass spectroscopy, 14) and soft X-ray polarimetry instruments. 15) The geometry of CAT gratings is very demanding, and silicon is the only available fabrication material currently identified.…”