Nickel silicide formation using multiple-pulsed laser annealing

Abstract

The effect of multiple-pulsed laser irradiation on Ni silicide formation in Ni(Ti) /Si system was

studied. A layered structure consisting of both crystalline NiSi2 and Ni-rich Ni–Si amorphous phases

with a protective TiOx overlayer was formed after five-pulsed laser annealing at 0.4 J cm−2.

Different solidification velocities caused by a variation in the atomic concentration across the melt

have led to the formation of this layered structure. On the other hand, by increasing the number of

laser pulses, a continuous layer of polycrystalline NiSi was obtained after a 20-pulsed laser annealing at 0.3 J cm−2 laser fluence. Its formation is attributed to a better elemental mixing which

occurred during subsequent pulses. Enhancement of surface absorption and remelting of the phases

formed is proposed as the mechanism governing the continuous NiSi layer formation.