Generation mechanism and in situ growth behavior of α-iron nanocrystals by electron beam induced deposition

The nanofabrication of iron-containing deposits with a precursor of Fe(CO)₅ and the growth of Α-Fe nanocrystals by Electron Beam Induced Deposition was investigated. The nanocryatals were formed by irradiation of a position-fixed focused electron beam for 1200s. The results show that Fe(CO)₅ molecules decomposed and debonded under electron beam formed target deposits contains amorphous Fe, C, and O. The Fe(CO)₅ bond dissociation energy is 6eV and the threshold energy to dissociate C-O bond is 12 eV. The secondary electrons (SE) with 50 eV energy are generated by inelastic scattering of incident primary electrons (PE). The SE can dissociate the gas molecules to deposit the Fe, C, and O molecules in the target, which develops the target deposits into a tip structure. The growth rate of Fe nanocrystals shows that its size is linearly dependent on the irradiation time and their growth speed is 0.08 nm/s.