Theory of workfunction control of silicides by doping for future Si-nano-devices based on fundamental physics of why silicides exist in nature

We have revealed by the first-principles calculations that the workfunction of silicide is controlled by the high-density dopant existing in the silicide itself, and the selective doping into Si or Ni site is essential to realize such control. In addition, we showed that these doping properties are closely related to fundamental physics of silicides; why Ni_xSi_y exists and why Au_xSi_y not exists in nature. These findings might give a new guideline to design silicide-electrode contacts for future 10nm nano-devices.