Morphological and structural characterizations of CrSi2 nanometric films deposited by laser ablation

The structure and morphology of chromium disilicide (CrSi2) nanometric films grown on 〈1 0 0〉 silicon substrates both at room temperature (RT) and at 740 K by pulsed laser ablation are reported. A pure CrSi2 crystal target was ablated with a KrF excimer laser in vacuum (∼3 × 10−5 Pa). Morphological and structural properties of the deposited films were investigated using Rutherford backscattering spectrometry (RBS), grazing incidence X-ray diffraction (GID), X-ray reflectivity (XRR), scanning (SEM) and transmission electron microscopy (TEM). From RBS analysis, the films' thickness resulted of ∼40 nm. This value is in agreement with the value obtained from XRR and TEM analysis (∼42 and ∼38 nm, respectively). The films' composition, as inferred from Rutherford Universal Manipulation Program simulation of experimental spectra, is close to stoichiometric CrSi2. GID analysis showed that the film deposited at 740 K is composed only by the CrSi2 phase. The RT deposited sample is amorphous, while GID and TEM analyses evidenced that the film deposited at 740 K is poorly crystallised. The RT deposited film exhibited a metallic behaviour, while that one deposited at 740 K showed a semiconductor behaviour down to 227 K.