Metal-induced crystallization of amorphous Si 1− xGe x by rapid thermal annealing

Abstract

Metal-induced crystallization (MIC) of amorphous Si 1− x Ge x ( x=0.2 and 0.3) thin films on SiO 2 by rapid thermal annealing (RTA) at 300–600 °C has been investigated. At low annealing temperature, Ni reacted with a-Si 1− x Ge x films to form Ni germanosilicides. The crystallization temperature of a-Si 0.7Ge 0.3 and a-Si 0.8Ge 0.2 was lowered from 500 to 400 °C and 600 to 500 °C, respectively, with capping Ni. The Ni germanosilicide grains were observed to form in the annealed Ni/a-Si 0.7Ge 0.3 and Ni/a-Si 0.8Ge 0.2 samples after annealing at 500 °C. The formation of island structure containing a small amount of Ge at the bottom of polycrystalline Si 1− x Ge x films is attributed to the preferential reactions of Ni with Si to Ge.