Focused Ion Beam Etching

The past decade has seen the growing development of focused ion beams for the preparation of semiconductor specimens for TEM evaluation for example, as compiled by Anderson and Walck [415], in an introductory book on the techniques and practice by Giannuzzi and Stevie [416], and in a paper describing the relation between ion beams and material interactions and FIB specimen preparation [417]. Only recently has the method been used in other materials sciences, such as metallurgy, and very little has been published on polymers. It is worthwhile to explore work done in this exciting area, especially in conjunction with TEM, AFM, and SEM imaging. 

isotactic PP 1% permanganate/in mixture of 10 4 1 sulfuric acid, 85% ortho-phosphoric acid, and water, for IS min at 60°C or 1-2 h at room temperature 

Cellulose acetate Acetone at -50°C, then cold ethanol 

HIPS 100 ml sulfuric acid, 30 ml phosphoric acid, 30 ml water, 5g chromic acid 

ABS-rubber phase slower on SAN matrix Sulfuric, chromic acids and water for 5 min at 70 C 

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Nagase, T., Gamo, K., Kubota, T., and S. Mashiko. 2006. Direct fabrication of nano-gap electrodes by focused ion beam etching. Thin Solid Films 499 279-284. 

Chelnokov A, Wang K, Rowson S, Garoche P, Lourtioz J-M (2000) Near-inlrared Yablonovite-like photonic crystals by focused-ion-beam etching of macroporous silicon. Appl Phys Lett 77 2943 Chen X, Steinhart M, Hess C, Gosele U (2006) Ordered arrays of mesoporous microrods Ifom recyclable macroporous silicon templates. Adv Mater 18 2153-2156... 

Wang K, Chelnokov A, Rowson S, Lourtioz J-M (2003) Extremely high-aspect-ratio patterns in macroporous substrate by focused-ion-beam etching the realization of three-dimensional lattices. Appl Phys A Mater Sci Proc 76 1013... 

Ultramicrotomy is sometimes also used to produce thin samples of solid materials, such as metals [13] which are, however, preferentially prepared by chemical- or ion-etching (see [1]) and focused ion beam (FIB) teclmiques [14]. 

High aspect ratio SFM probes can be also made by a focused-ion-beam (FIB) technique [209-211]. Microtips were reproducibly grown up to 1.0 pm in length and 0.1 pm in diameter. A tip radius as low as 5 nm could be achieved and was found to degrade only slightly after extensive SFM imaging. Conventional tips can be modified by etching techniques so that a sharper probe apex is provided [212]. 

However, to evaluate the properties and size constraints of only the ferroelectric capacitor and its materials there are easier approaches in terms of manufacturing. So typically stand-alone capacitors are manufactured on continuous or structured bottom electrodes with structured top electrodes. A powerful tool is fib (focused ion beam) where a beam of highly accelerated ions is used to etch or even deposit materials. Stand-alone sub-micron ferroelectric capacitors are shown in Figure 17.3, which have been etched from a continuous thin film structure of... 

In a variation of the nanosphere hthography approach Lee et al. [138] used reactive ion etching to reduce the size of polystyrene spheres before evaporation of Ag onto the structure. Removal of the spheres then produces a nanohole array (Figure 6.11) similar to that fabricated by focused ion beam mihing. For benzenethiol Lee et al. obtained enhancement factors of up to 8 x 10 for these nanohole structures. 

S. Chattopadhyay and P. W. Bohn, Direct-write patterning of microstructured porous silicon arrays by focused-ion-beam Pt deposition and metal-assisted electroless etching, J. Appl. Phys. 96, 6888-6894 (2004). 

Figure 3.5 Ion beam etching apparatus a triode. In an ton beam apparatus the beam diameter is approximately 8 cm. The substrates are mounted on a moveable holder allowing etching of the larger substrate areas. The coils focus the ion beam and densify the ion flux. 

Kometani, R., Morita, T., Watanabe, K. et al. 2003. Nozzle-nanostructure fabrication on glass capillary by focused-ion-beam chemical vapor deposition and etching. Japanese Journal of Applied Physics 42 4107-4110. 

Sadoh, T., Eguchi, H., Kenjo, A., and M. Miyao. 2003. Etching characteristics of SiOj irradiated with focused ion beam. Nuclear Instruments and Methods in Physics Research B 206 478-481. 

To make 2 nm diameter SiN nanopores, a layer of nitride film is first deposited on top of a silicon wafer, and the sUicon wafer is then etched from the backside with KOH to leave a small region of freestanding SiN membrane. Either an electron beam hthography or ion milling step will create a nanopore of tens of nanometers. Further exposure of the nanopore to focused ion beam will gradually shrink the pore to 1—2 nm in diameter. 

SEM combined with focused ion beams (FIB), usually gallium ion beams, are used in order to obtain the cross sectional images near the sample surface. The sample surfaces can be etched in a nanoscale by spattering the surface atoms with... 

Deposition on stub + drying of specimen freeze-fracture chemical etching focused ion beam... 

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