Simultaneous detection of positive and negative secondary ions

Abstract

A secondary ion mass spectrometer (SIMS) instrument is described that is configured with two SIMSdetectors that are both low-field extraction, quadrupole-based filters. Secondary ions are generated by sputtering with a liquid-metal ion gallium source and column of the type that is common on two-beam electron microscopes. The gallium ion beam, or focused ion beam achieves sub-100 nm focus with a continuous current of up to 300 pA. Positive secondary ions are detected by one SIMSdetector, and simultaneously, negative secondary ions are detected by the second SIMSdetector. The SIMSdetectors are independently controlled for recording mass spectra, concentration depth profiles, and secondary ion images. Examples of simultaneous positive and negative SIMS are included that demonstrate the advantage of this facility for surface analysis and depth profiling. The SIMS secondary ion collection has been modeled using the ray tracing program simion (“simion”, Scientific Instrument Services, Inc., Ringoes, NJ, 08551-1054, see http://www.simion.com) in order to understand the interaction of the secondary ions of opposite polarities in the extraction volume for the purpose of optimizing secondary ion collection

Structure, Chemistry, and Charge Transfer Resistance of the Interface between Li7La3Zr2O12 Electrolyte and LiCoO2 Cathode

“…Typical positive and negative SIMS mass spectra were obtained before depth profiling in order to check on the correct peak positions on the mass/charge scale of the secondary ions of interest for each detector used during the depth profiles.Both polarity SIMS ions are detected simultaneously during the depth profiles. 94 The FEI SIMS detector is set up for negative ion detection and HIDEN SIMS detector set up for positive ion detection. Typical positive and negative SIMS mass spectra were obtained before depth profiling in order to check on the correct peak positions on the mass/charge scale of the secondary ions of interest for each detector used during the depth profiles.…”

“…Both polarity SIMS ions are detected simultaneously during the depth profiles. 93 The FEI SIMS detector is set up for negative ion detection and HIDEN SIMS detector set up for positive ion detection. Typical positive and negative SIMS mass spectra were obtained before depth profiling to check on the correct peak positions on the mass/charge scale of the secondary ions of interest for each detector used during the depth profiles.…”

“…Typical positive and negative SIMS mass spectra were obtained before depth profiling to check on the correct peak positions on the mass/charge scale of the secondary ions of interest for each detector used during the depth profiles. Both polarity SIMS ions are detected simultaneously during the depth profiles . The FEI SIMS detector is set up for negative ion detection and HIDEN SIMS detector set up for positive ion detection.…”

Garnet Electrolytes for Solid State Batteries: Visualization of Moisture-Induced Chemical Degradation and Revealing Its Impact on the Li-Ion Dynamics

“…The FIB-SIMS instrument used in this study has the advantage of selected area analysis by high resolution secondary electron and ion imaging of the sample, large depth probing to several micrometres and simultaneous dual-polarity secondary ion detection 28 . By using small analysis crater sizes (7 μm by 7 μm) in the FIB-SIMS instrument we are thus able to select areas within the larger grains of Ga0.15-LLZO.…”

“…Simultaneous negative and positive secondary ions were detected in dynamic SIMS mode (> 10 14 particles cm -2 incident on the sample) using both FEI and Hiden EQS quadrupole detectors. The FIB-SIMS instrument is equipped with detectors for secondary electrons, positive ions and negative ions to allow an asynchronous semi-simultaneous signal acquisition 28 . The crater depth was calibrated from the SEM image recorded with the sample tilted at 45°.…”