High-resolution transmission electron microscopy of silicide formation and morphology development of Ni/Si and Ni/Si1−xGex

Abstract

Nickel-silicide phase formation in the Ni/Si and Ni/Si1−xGex (x=0.20) systems and its correlation with variations in sheet resistance have been studied using high-resolution transmission electron microscopy (HRTEM) and related techniques. Following a 500°C anneal, uniform and low-resistivity NiSi and NiSi1−xGex (x<0.20) crystalline films were formed in the respective systems. Annealed at 900°C, NiSi2, in the form of pyramidal or trapezoidal islands, is found to replace the NiSi in the Ni/Si system. After a 700°C anneal, threading dislocations were observed for the first time in the Ni/Si1−xGex system to serve as heterogeneous nucleation sites for rapid lateral NiSi1−xGex growth.