Structural and trap properties of polycrystalline semiconducting FeSi2 thin films

The structural and trap properties of polycrystalline beta-FeSi2 thin films , grown by rapid thermal or conventional furnace annealing on (100) Si subs trates of high resistivity, were investigated by transmission electron micr oscopy and low-frequency noise measurements performed at room temperature w ith the current I as a parameter. The power spectral density of the current fluctuations shows a 1/f' (with gamma > 1) behaviour and is proportional t o I-beta (with beta < 2). Based on an analytical model for the spectral cur rent density, the trap density at the Fermi level has been determined using the experimental data of Hall measurements. The structural properties and the trap density of the beta-FeSi2 thin films are discussed in terms of the annealing method and the annealing conditions.