Pulsed KrF laser annealing of Ni/Si0.76Ge0.24 films

Abstract

Pulsed KrF laser annealing can suppress the island structure formation and Ge segregation associated with the interfacial reactions of Ni/Si0.76Ge0.24. For the Ni/Si0.76Ge0.24 films annealed at an energy density of 0.1–0.3 J/cm2 nickel germanosilicide associated with the amorphous overlayer was formed, while at energy densities above 0.4 J/cm2 cellular structures of Ge-deficient Si1−xGex islands surrounded by Ni(Si1−xGex)2 due to the constitutional supercooling occurred. For the continuous Ni(Si1−xGex) films grown at 200 °C, subsequent laser annealing at a higher energy density of 0.6–1.0 J/cm2 caused transformation into homogeneous Ni(Si0.76Ge0.24)2 films without island structure and Ge deficiency which readily appeared on furnace annealing at temperatures above 400 °C. At energy densities above 1.6 J/cm2 the same cellular structures as described above were also noted.