Correlative Microscopy Using TEM and SIMS: Parallel Ion Electron Spectrometry (PIES) for High-Resolution, High-Sensitivity Elemental Mapping for Applications in Materials Science and Biology

Abstract

The capability to simultaneously obtain high spatial resolution and high chemical sensitivity is of paramount importance to gain deeper understanding in physical and biological sciences. The Transmission Electron Microscopy (TEM) offers superior spatial resolution, but, the traditional analytical capabilities associated with electron microscopy such as the Energy Dispersive Spectroscopy (EDS) or Electron Energy-Loss Spectroscopy (EELS) are unfortunately inadequate for characterizing samples containing trace elements (at best 0.1 at. %) or for mapping isotopic distributions [1,2]. On the other hand, Secondary Ion Mass Spectrometry (SIMS) provides extraordinary chemical sensitivity (down to ppm or even ppb) and high dynamic range, but, offers poor lateral resolution [3]. An ex-situ combination of TEM and SIMS in an attempt to overcome the limitations of the techniques taken individually is prone to sample modifications and other artefacts [4]. To overcome the intrinsic instrumental limitations, we have made an in-situ combination to complement the high-sensitivity of SIMS with the exceptional spatial resolution offered by TEM, by developing the correlative TEM-SIMS technique.