FIB preparation and TEM analytics on AlSi1 bond pads

The method of Focused Ion Beam (FIB) for a TEM target preparation is a very efficient technique for an examination regarding the formation of interconnects in bond pads of a very low extension (25 mu m AlSi1 wire on a Cu/Ni/Au metallized area of a printed circuit board) and allows to precisely remove a lamella from the sample range of interest. The in-situ lift-out process successfully permits to prepare thinner foils (abt. 40 nm) as compared to the ex-situ lift-out process, on which EFTEM mappings and HRTM examinations become possible in the interface area between the bonding wire and the metallized layer. Along with the application of the FIB as a scanning ion microscope, such examinations provide new findings on the microstructure of bond pads and the construction of the interface and will expand a comprehension of the way interconnects build up during wire bonding.