Interfacial reactions of Ni on Si0.76Ge0.24 and Si by pulsed laser annealing

Abstract

Pulsed KrF laser annealing and vacuum annealing on the interfacial reactions of Ni/Si0.76Ge0.24 and Ni/Si were studied. For the Ni/ Si0.76Ge0.24 films annealed at temperatures above 300 degrees C, some Ge-rich Si1-xGex grains were formed between the Ge-deficient Ni germanosilicide grains, resulting in the island structure. For Ni/Si films homogeneous epitaxial NiSi2 films could be grown even at 600 degrees C. Ni silicide (germanosilicide) associated with the amorphous overlayer was generally formed at lower energy densities for Ni/Si, NiSi/Si, Ni/Si0.76Ge0.24 and Ni(Si1-xGex) /Si0.76Ge0.24 systems, respectively. At higher energy densities constitutional supercooling occurred. The energy densities at which constitutional supercooling appeared were higher for NiSi and Ni(Si1-xGex) than for Ni. For the continuous Ni(Si1-xGex) films grown at 200 degrees C in a vacuum furnace, subsequent laser annealing at an energy density of 0.6-1.0 J cm(-2) have shown to render homogeneous Ni(Si0.76Ge0.24)(2) and Si0.76Ge0.24 films without the island structure and Ge segregation. (C) 1998 Elsevier Science S.A. All rights reserved.