Formation of nickel silicides in the Ni/Si3N4/Si system during rapid thermal annealing

Abstract

Effect of rapid thermal annealing (RTA) at 800, 1000, and 1200 °C on the Ni/Si3N4/Si system has been studied employing electron microscopy, Auger electron spectroscopy, and x-ray diffraction analysis. Formation of NiSi or NiSi2 silicides on the Ni/Si3N4 interface and of NiSi2 silicide on the Si3N4/Si interface was observed after RTA. This was a result of the diffusion of Si into deposited 250-nm-thick Ni layer and the diffusion of Ni through 140-nm-thick amorphous Si3N4 layer into the Si substrate. The diffusion coefficient of Ni in amorphous Si3N4 was estimated to be D≂103 exp(−3.2 eV/kT), cm2/s.