Full range workfunction tunning of MOSFETs using interfacial yttrium layer in fully germanided Ni gate

Abstract

In this work, the tuning of the nickel fully germanided metal gate workfunction via a Y/Ge/Ni gate stack structure was demonstrated. By varying the yttrium interlayer thickness from 0 to 9.6nm, a full range of workfunction tuning from 5.11eV to 3.8eV can be achieved. We showed that the chemical potential of the material adjacent to the gate electrode/gate insulator plays an important role in the determination of the workfunction. The gate stack is thermally stable up to 500°C annealing. © The Electrochemical Society.