Enhancing silicide formation in Ni/Si(111) by Ag-Si particles at the interface

Abstract

Compound formation at a metal/semiconductor interface plays crucial roles in the properties of many material systems. Applications of Ni silicides span numerous areas and have the potential to be used as new functionalities. However, the magnetic properties of ultrathin Ni layers on silicon surfaces and related chemical compositions at the interface are not fully understood and the influence of Ag additives on the reactivity of Ni/Si(111) remain unclear. We report herein on the fact that the dominant species produced at the interface is NiSi, which is produced by the spontaneous formation of strong bonds between Ni and Si atoms. Assuming that a Ni layer is formed over a NiSi layer with the total coverage as a constraint, we established a chemical shift-related concentration model that, in effect, represents a practical method for determining the amount of ultrathin Ni silicides that are produced at the buried interface. The formation of Ag-Si particles provide a viable strategy for enhancing silicide formation via a specific interaction transfer mechanism, even at room temperature. The mechanism is related to differences in the enthalpies of formation ΔH Ag-Si , ΔH Ni-Ag , and ΔH Ni-Si , for these phases and provides insights into strategies for producing ultrathin silicides at a buried interface.

Electronic Properties and Structure of Silicene on Cu and Ni Substrates

“…This layer is used as a Cu diffusion barrier [ 4 ]. Nickel silicide, formed on the contact surface [ 5 ], reduces the contact resistance between the metal and Si and also improves the adhesion of the metal to Si [ 6 ]. Thus, three chemical elements (Si, Ni and Cu) in direct contact with each other are involved in the creation of a relatively inexpensive and highly efficient solar battery.…”