Influence of the annealing schemes on the formation and stability of Ni(Pt)Si thin films: partial, laser, total, and unique anneal
Résumé
In this study, the impact of various annealing schemes on the formation and agglomeration mechanisms of ultra-thin Ni(Pt)Si films is investigated. To this end, 11±1 nm-thick Ni(Pt)Si films are grown on 300 mm Si(100) wafers using various classical rapid thermal annealing procedures as well as laser annealing. The obtained silicide films are then submitted to an additional annealing, between 500 °C and 800 °C, to evaluate their stability at high temperature. The correlation between the as-grown Ni(Pt)Si layer properties and their capability to withstand agglomeration is analysed via a complementary approach of several techniques (Rs, ellipsometry, TEM-EDX, SEM, and EBSD). Texture comparisons for ultra-thin films give deeper insights into the role of the NiSi(010) and NiSi(013) orientations in the agglomeration phenomenon. Depending on the annealing schemes used during the formation of the silicide, there is a strong correlation between the initial microstructure of Ni(Pt)Si films and the subsequent degradation. Indeed, cross-analyses of these different key parameters indicates that the presence of small Ni(Pt)Si grains (40 nm) obtained after laser anneal, and a high ratio of Ni(Pt)Si grains oriented towards the (013) direction appear to be more efficient in delaying the agglomeration to higher temperatures.