Investigation of FIB assisted CoSi2 nanowire growth

The ion beam synthesis process of CoSi2 by writing stoichiometric ion implantation and subsequent annealing has been studied. For this a Focused Ion Beam (FIB), equipped with a Co36Nd64 alloy liquid metal ion source, was applied. Si(1 0 0) and (1 1 1) wafers were implanted with 60 keV Co2+ ions in the dose range of 2 × 1016–2 × 1017 cm−2. The implantation parameters, like pixel dwell time, relaxation time, dose rate as well as the pixel overlapping factor were investigated. During subsequent annealing CoSi2 nanostructures with dimensions down to 10 nm have been achieved. To investigate the silicide formation more in detail the annealing process was done in situ in a transmission electron microscope (TEM) on a pre-dimpled and FIB implanted samples of a Si(1 1 1). The formation of the cobalt silicide nano-crystals was monitored by plane-view TEM imaging during a 30 min heat treatment at 600 °C in vacuum.