Metal-induced crystallization of amorphous Si1-xGex by rapid thermal annealing

Metal-induced crystallization (MIC) of amorphous Si1-xGex (x=0.2 and 0.3) thin films on SiO2 by rapid thermal annealing (RTA) at 300-600 degreesC has been investigated. At low annealing temperature, Ni reacted with a-Si1-xGex films to form Ni germanosilicides. The crystallization temperature of a-Si0.7Ge0.3 and a-Si0.8Ge0.2 was lowered from 500 to 400 degreesC and 600 to 500 degreesC, respectively, with capping Ni. The Ni germanosilicide grains were observed to form in the annealed Ni/a-Si0.7Ge0.3 and Ni/a-Si0.8Ge0.2 samples after annealing at 500 degreesC. The formation of island structure containing a small amount of Ge at the bottom of polycrystalline Si(1-x)Gex films is attributed to the preferential reactions of Ni with Si to Ge. (C) 2004 Elsevier B.V. All rights reserved.