This paper investigates the work function adjustment of a full silicidation （Ni-FUSI） metal gate. It is found that implanting dopant into poly-Si before silicidation can modulate the work function of a Ni-FUSI metal gate efficiently. With the implantation of p-type or n-type dopants,such as BF2 ,As,and P,the work function of a Ni-FUSI metal gate can be made higher or lower to satisfy the requirement of pMOS or nMOS, respectively. But implanting a high dose of As into a poly-Si gate before silicidation will cause the delamination effect and EOT loss,and thus As dopant is not suitable to be used to adjust the work function of a Ni-FUSI metal gate. Due to the EOT reduction in the FUSI Process,the gate leakage current of a FUSI metal gate capacitor is larger than that of a poly-Si gate capacitor.
