MSS niche analysis on substrates: PFIB and advanced imaging method

Preparing cross-sectional substrates by Ga FIBs is time-consuming due to their lateral size.
Some drawbacks, such as curtain effects and re-deposition, might cause severe problems for further SEM analysis.
With the help of MSS new-generation PFIB and the advanced imaging method, clean cross-sectional substrates with less curtain effects can be prepared in a reasonable time frame and most importantly, the inner fine structures of substrates can be clearly observed and investigated.
One of examples is shown in these images.
a is a cross-sectional image of the substrate prepared by normal PFIB recipes (the sample is dismounted from a old PC in MSS), where severe curtain effects can be clearly seen, as marked by the red arrows.
With the help of MSS optimized PFIB recipe, curtain effects can be drastically improved as shown in b.
The task is how to resolve the boundaries between neighboring layers which cannot be easily obtained by normal imaging methods.
To achieve such purpose, advanced imaging method, energy-filter SEM (FESEM), is then utilized and the result is shown in c.
d is a further zoom-in image at the location marked by the green dotted rectangle in c.

These images with different magnifications demonstrate another case of how to combine MSS optimized PFIB recipe and the advanced imaging method, FESEM, to improve the curtain effects and resolve the detailed fine structures of the substrate.
Zoom-in locations are marked by the green dotted rectangles, respectively.
The red arrows indicate two neighboring layers can be clearly resolved by the advanced imaging method.