Prakt. Met. Sonderband 46 (2014) 31 
Another possibility not shown here is to prepare a thin lamella across the film on substrate 
by repeating the process shown in Fig. 2 from the other side as well, as demonstrated 
ation of a material cross- recently elsewhere [25]. Such lamellas, where the film of interest is on top of the prepared 
al etching, since corners lamella, can serve as pre-form for shaping bending beams in the FIB to measure stresses 
"|B, such cross-sections in the thin films, an example of which is shown below. 
beam ion milling, large 
ar to the material surface 
in Fig. 2, the sample is 2.2.3 MASK-STRUCTURED MICROSAMPLES 
Oo sputter a cross-section 
icture and film/substrate Finally, once a free-standing lamella was created by either electrochemical etching or 
broad beam ion slicing (Fig. 4a), in the next step the sample can be rotated by 90° and a 
protecting stencil mask put in place on top (b), after which another ion milling process is 
performed (c), similar to what was suggested in [26]. This then allows the FIB-less creation 
of micro-samples (Fig. 4d). 
a) Ar be- 
film on substrate. 
n milling. However, when 
to prepare free standing 
on substrates this can in 
strate [24]. However, the 
kind of film/substrate as 
area of interest) with the 
rge free-standing lamella Fig. 4: Preparation of micro-tensile samples using stencil masks during broad ion beam 
uring (c, d). For very thin sputtering of a previously thinned lamella. 
ge of the film. 
Notably, this approach is limited to somewhat larger samples sizes in the upper 
micrometer regime. Nonetheless, this is a very exciting range that is typically only 
accessible by lithographic techniques, as it is too small for conventional machining, and 
too large or very ineffective for FIB machining. Given the limited flexibility of lithographic 
processes with respect to the used materials, we think that this mask supported broad 
beam ion milling approach, which can be applied to literally any kind of material that 
tolerates vacuum and low energy Ar ion impact, is definitely a very valuable sample 
fabrication strategy. 
2.3 FOCUSSED ION BEAM MILLING 
In the following paragraphs, we will detail the steps to prepare miniaturized samples with 
well defined geometries [19, 27-30], and in particular without the taper, which is typical for 
many of these micro-samples [31]. Needles or lamellas, fabricated in the previous steps. 
will serve as pre-forms. 
hat can subsequently be