Ni silicide layer formation using low-energy ion beams

In this paper, we report on an Si(1 1 1) surface irradiated with a mass-selected low-energy 58Ni− ion beam at 100 eV in order to form a Ni silicide layer. The Ni silicide phase formed at 230 °C in this study is Ni-rich Ni2Si, in contrast to Si-rich disilicide NiSi2, ordinarily formed when high-energy Ni ions or thermal Ni beams react with a heated Si substrate. In addition, this layer is formed epitaxially on Si even at a low substrate temperature of 230 °C, while conventional Ni-rich silicidation induces a polycrystalline Ni silicide layer. This suggests that the reaction of the silicide formation with energetic particles in a low energy region is different from that using higher or thermal energy particles.