Magnetic Sector Secondary Ion Mass Spectrometry on FIB-SEM Instruments for Nanoscale Chemical Imaging

Abstract

The structural, morphological, and chemical characterization of samples is of utmost importance for a large number of scientific fields. Furthermore, this characterization very often needs to be performed in three dimensions and at length scales down to the nanometer. Therefore, there is a stringent necessity to develop appropriate instrumentational solutions to fulfill these needs. Here we report on the deployment of magnetic sector secondary ion mass spectrometry (SIMS) on a type of instrument widely used for such nanoscale investigations, namely, focused ion beam (FIB)–scanning electron microscopy (SEM) instruments. First, we present the layout of the FIB-SEM-SIMS instrument and address its performance by using specific test samples. The achieved performance can be summarized as follows: an overall secondary ion beam transmission above 40%, a mass resolving power ( M /Δ M ) of more than 400, a detectable mass range from 1 to 400 amu, a lateral resolution in two-dimensional (2D) chemical imaging mode of 15 nm, and a depth resolution of ∼4 nm at 3.0 keV of beam landing energy. Second, we show results (depth profiling, 2D imaging, three-dimensional imaging) obtained in a wide range of areas, such as battery research, photovoltaics, multilayered samples, and life science applications. We hereby highlight the system’s versatile capability of conducting high-performance correlative studies in the fields of materials science and life sciences.

Toward Operando Structural, Chemical, and Electrochemical Analyses of Solid-State Batteries Using Correlative Secondary Ion Mass Spectrometry Imaging

“…This further underlines the necessity for direct chemical imaging. This need is fulfilled by nanoscale SIMS imaging, which allows chemical mapping with a lateral resolution of 15 nm and a depth resolution of ∼4 nm . The pre- and post-cycling ROIs do not represent the exact same location, as it is not possible to predict where degradations and potential Li-dendrites will emerge.…”

“…SIMS imaging was performed using a Thermo Fisher Scios DualBeam FIB-SEM equipped with an inhouse developed double-focusing magnetic sector SIMS system, which allows the detection of multiple masses in parallel. 17,19 The FIB consists of a gallium liquid metal ion source producing 69 Ga + primary ions. The secondary ions that were collected and imaged are: 7 Li + , 139 La + , and 155 LaO + .…”

“…Furthermore, a custom-made IGTS (developed together with Ferrovac AG see Supporting Information Figure S4) permits a contamination-free sample transfer from glove box to instrument and vice versa. The FIB-SEM instrument is equipped with an in-house-designed magnetic sector SIMS, and details about the FIB-SEM-SIMS instrument and its performance can be found elsewhere . The implementation of SIMS in the present operando study presents a huge advantage in terms of chemical analysis, allowing to detect and measure the distribution of low-Z elements such as H and Li. , Li often plays an important role in degradation mechanisms due to its high ionic mobility and capability to form dendrites, − and therefore, it is essential to observe the evolution of the Li distribution.…”

Thermal Recovery of the Electrochemically Degraded LiCoO2/Li7La3Zr2O12:Al,Ta Interface in an All-Solid-State Lithium Battery

“…The SIMS system is based on a double-focusing magnetic sector and allows parallel detection of multiple masses. Other details of the instrument can be found elsewhere …”

“…Other details of the instrument can be found elsewhere. 42 SIMS images are recorded with an accelerating energy of the primary ions of 30 keV and currents between 0.3 and 0.5 nA. The sample stage is biased to a potential of +500 V, resulting in a primary ion impact energy of 29.5 keV.…”