Use of permanent marker to deposit a protection layer against FIB damage in TEM specimen preparation

Abstract

SummaryPermanent marker deposition (PMD), which creates permanent writing on an object with a permanent marker, was investigated as a method to deposit a protection layer against focused ion beam damage. PMD is a simple, fast and cheap process. Further, PMD is excellent in filling in narrow and deep trenches, enabling damage-free observation of high aspect ratio structures with atomic resolution in transmission electron microscopy (TEM). The microstructure, composition, gap filling ability and planarization of the PMD layer were studied using dual beam focused ion beam, transmission electron microscopy, energy dispersive X-ray spectroscopy and electron energy loss spectroscopy. It was found that a PMD layer is basically an amorphous carbon structure, and that such a layer should be at least 65 nm thick to protect a surface against 30 keV focused ion beam damage. We suggest that such a PMD layer can be an excellent protection layer to maintain a pristine sample structure against focused ion beam damage during transmission electron microscopy specimen preparation.

In situ high-temperature TEM observation of material escape from a surface of CoFeNi/Cu/ZrAlO composite into the amorphous carbon layer

“…The black ink carbon layer was amorphous and appeared to be porous (Fig. 1c) [23]. The pores intersected and formed a connected network (Fig.…”

“…We used the following procedure to prepare the TEM specimens, which played a crucial role in the visualization of the described phenomena [22,23]. The TEM specimen was prepared on a molybdenum TEM grid using an FIB instrument (FEI Helios NanoLab DualBeam).…”

“…The TEM specimen was prepared on a molybdenum TEM grid using an FIB instrument (FEI Helios NanoLab DualBeam). The Ga ions used in the FIB process induce damage in the TEM specimen [22][23][24][25][26]. To prevent top surface damage caused by the ion beam, the area of interest was marked with black ink carbon (permanent marker) [23].…”

“…The Ga ions used in the FIB process induce damage in the TEM specimen [22][23][24][25][26]. To prevent top surface damage caused by the ion beam, the area of interest was marked with black ink carbon (permanent marker) [23]. Next, a carbon strip was coated with a thin Pt film (around 10 nm) in order to provide conductivity and protection to the carbon strip.…”

“…Next, a carbon strip was coated with a thin Pt film (around 10 nm) in order to provide conductivity and protection to the carbon strip. Finally, the W protective layer was deposited using FIB (FB-2100, Hitachi), during which the thin Pt film was subjected to high-energy ion bombardment to break the Pt film into nanosized fragments [22,23]. The layer structure on the TEM specimen after FIB processing before heating is shown in Fig.…”