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Focused ion beam (FIB) techniques have been used for the preparation of high quality TEM and SEM specimens [1] because of some advantages:
i) FIB allows for rapid production of site specific (within 50 nm) TEM specimens.
ii) FIB has a lower preferential sputtering rate than any other conventional TEM sampling method [2].
However, this technology also has some drawbacks, which we want to minimize:
i) The use of high energy Ga+1 ions for milling leads to the formation of damaged, amorphous layers, and formation of voids in some materials (e.g. germanium) [13, 14] at the faces of the sample. These amorphous layers are produced by direct damage of the ion beam irradiation and redeposition of sputtered materials. The formation of these layers and their minimization have been investigated by many researchers [3 - 12].
ii) The curtain effect.
Table 4503 summarizes the advantages and disadvantages of FIB technique for TEM specimen preparations.
Table 4503. Advantages and disadvantages of FIB technique for TEM specimen preparations.
| Advantages |
Disadvantages |
• Site-specific
• Multiple specimens from a small area
• Time-efficient (Typically 1 nm/min for Si at 1 keV, 150 pA, 30° tilt, 10 μm x 20 μm area)
• Samples can be applied to HRTEM, HAADF, tomography, holography, and microanalysis
• Beam strength is adjustable |
• Amorphous contamination
• Ga implantation
• Physical and electrical properties can be affected |
[1] Langford RM. 2006. Focused ion beams techniques for nanomaterials characterization. Microsc Res Tech 69:538–549.
[2] Kamino T, Yaguchi T, Kuroda Y, Ohnishi T, Ishitani T, Miyahara Y, Horita Z. 2004. Evaluation of TEM samples of an Mg-Al alloy prepared using FIB milling at the operating voltages of 10 kV and 40 kV. J Electron Microsc 53:459–463.
[3] Cairney JM, Munroe PR. 2003. Redeposition effects in transmission electron microscope specimens of FeAl-WC composites prepared using a focused ion beam. Micron 34:97–107.
[4] Hata S, Sosiati H, Kuwano N, Itakura M, Nakano T, Umakoshi Y. 2006. Removing focused ion beam damages on trasmission electron microscopy by using a plasma cleaner. J Electron Microsc 55:23–26.
[5] Kamino T, Yaguchi T, Kuroda Y, Ohnishi T, Ishitani T, Miyahara Y, Horita Z. 2004. Evaluation of TEM samples of an Mg-Al alloy prepared using FIB milling at the operating voltages of 10 kV and 40 kV. J Electron Microsc 53:459–463.
[6] Kato NI. 2004. Reducing focused ion beam damage to transmission electron microscopy samples. J Electron Microsc 53:451–458.
[7] Ko D-S, Park YM, Kim S-D, Kim Y-W. 2007. Effective removal of Ga residue from focused ion beam using a plasma cleaner. Ultramicroscopy 107:368–373.
[8] Reiner JC, Nellen P, Sennhauser U. 2004. Gallium artefacts on FIBmilled silicon samples. Microelectron Reliability 44:1583–1588.
[9] Rubanov S, Munroe PR. 2004. FIB-induced damage in silicon. J Microsc 214:213–221.
[10] Wang Z, Kato T, Hirayama T, Kato N, Sasaki K, Saka H. 2005. Surface damage induced by focused-ion-beam milling in a Si/Si p-n junction cross-sectional specimen. Appl Surf Sci 241:80–86.
[11] Yabuuchi Y, Tametou S, Okano T, Inazato S, Sadayama S, Yamamoto Y, Iwasaki K, Sugiyama Y. 2004. A study of the damage on FIB-prepared TEM samples of AlxGa1-xAs. J Electron Microsc 53:471–477.
[12] Yu J, Liu J, Zhang J, Wu J. 2006. TEM investigation of FIB induced damages in preparation of metal material TEM specimens by FIB. Mater Lett 60:206–209.
[13] Romano L, Impellizzeri G, Tomasello M V, Giannazzo F,
Spinella C and Grimaldi M G 2010 J. Appl. Phys.
107 084314
[14]Kolíbal M, Matlocha T, Vystavěl T,
and Šikola T, Low energy focused ion beam milling of silicon and germanium nanostructures, Nanotechnology, 22 (2011) 105304
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