High spatial resolution imaging of helium isotope by TOF‐SNMS

Abstract

Laser ionization mass nanoscope is a time-of-flight sputtered neutral mass spectrometer associated with laser post-ionization by tunneling effect. A spherical and chromatic aberration corrector is installed in the primary ion column. The lateral spatial resolving power of He imaging of solid surface has been evaluated by scanning image using a probe diameter of 90 nm from crater edge slope of a He ion-implanted Si substrate. Helium distribution from the scanning image is quantitatively equivalent with depth profiling analysis from surface of the same substrate, indicating that spatial resolving power of 20 nm for depth resolution has been achieved on the He scanning image through use of oblique incident effect of the primary beam.

Mass Spectrometry Imaging: A Review of Emerging Advancements and Future Insights

“…55 Numerous other notable advancements have also been made to improve spatial resolution recently. 56–59 …”

Electronic data acquisition and operational control system for time‐of‐flight sputtered neutral mass spectrometer

“…The NI PXI‐7952R is an NI FlexRIO field‐programmable gate array (FPGA) module, and the NI PXIe‐6581 is a 200 MHz digital adapter module for the FPGA (hereafter 7952R‐6581). The timing controls for the TOF‐MS and the primary ion beam pulse of LIMAS are applied by the 7952R‐6581 . Therefore, the 7952R‐6581 produces the timing patterns required by LIMAS under full adaptation.…”

Evaluation of multi‐turn time‐of‐flight mass spectrum of laser ionization mass nanoscope

“…The basic instrumental configuration, operation sequence, and preliminary performance of LIMAS have been described in other studies . The development of the timing control of operation is described in other studies in this issue . The femtosecond laser system has been replaced for obtaining stronger fields for tunneling ionization of inert elements such as He.…”

“…The length of one cycle is 1.308 m. The timing of extraction into MULTUM II and release into the detector (i.e. the number of multi‐turn cycles) of the ion sequence can be controlled using the on‐off control of an incident sector electrode voltage and an exit sector electrode voltage …”