TiC and TaC deposition by pulsed laser ablation: a comparative approach

Titanium and tantalum monocarbides have been evaporated by means of doubled Nd-YAG laser and deposited on oriented silicon substrates. The gaseous phase and the deposited films have been characterised by mass spectrometry, optical imaging (ICCD camera) and electron microscopy analysis (SEM, TEM), X-ray diffraction, X-ray photoelectron spectroscopy (XPS), respectively. The major differences between the two systems, observed in the gas phase analysis concern the plume composition and morphology which are strictly related to the films characteristics. In fact, while in the case of TiC it is possible to identify several evaporation mechanisms as a function of the laser fluence leading to different film composition, the ablation of TaC can be interpreted mainly in terms of a single process. The steps of the film growth were also studied for both systems.