Effect of nickel on clean silicon surfaces: Transport and structure

Abstract

Abstract Nickel behaviour on clean Si(111), Si(100) and Si(100) surfaces has been studied. It has been found that the coefficients of nickel diffusion on silicon surfaces are significantly lower than those of its diffusion in the bulk. Nickel transport along silicon surfaces is realized by its diffusion through the bulk with the subsequent diffusion of nickel to the surface due to the lowering of its solubility in silicon with decreasing temperature. Nickel induces the formation of a number of surface structures on Si(111), Si(100) and Si(110) planes. A correlation has been established between nickel concentration and surface structure. Surface concentrations of nickel causing surface reconstruction are usually lower than their minimum values required for the formation of surface structures containing at least one nickel atom in a unit cell. This can be due to the fact that nickel atoms are localized at a certain depth from the surface. It is shown that depending on the cooling rate, nickel on silicon surfaces can be in two different states.