Solid phase growth of NiSi in polycrystalline Si on SiO2 with Cl plasma containing NiCl

Abstract

Nickel silicidation of polycrystalline Si (poly Si) on SiO2 is possible by treating a poly Si surface with a Cl plasma containing NiCl. This process allows the fabrication of NiSi film with a uniform concentration profile on SiO2. The nickel silicide growth depends on the plasma power and the substrate temperature. A TEM observation indicates the presence of Si layer on the growing surface, which suggests that the surface segregation of Si might play an important role in the solid phase growth of NiSi. RBS measurements evidence that the average Ni concentration increases with the plasma treatment time, which suggests the Ni condensation by Ni deposition and selective Si etching on the growing surface. Based on the experimental results, we discuss the growth mechanism of nickel silicide prepared through the Cl plasma containing NiCl.