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.
Ge and Si p-channel metal-oxide-semiconductor field-effect-transistors （p-MOSFETs） with hafnium silicon oxynitride （HfSiON） gate dielectric and tantalum nitride （TAN） metal gate are fabricated. Self-isolated ring-type transistor structures with two masks are employed. W/TaN metal stacks are used as gate electrode and shadow masks of source/drain implantation separately. Capacitance-voltage curve hysteresis of Ge metal-oxide-semiconductor （MOS） capacitors may be caused by charge trapping centres in GeOx （1 〈 x 〈 2）. Effective hole mobilities of Ge and Si transistors are extracted by using a channel conductance method. The peak hole mobilities of Si and Ge transistors are 33.4 cm2/（V.s） and 81.0 cm2/（V.s）, respectively. Ge transistor has a hole mobility 2.4 times higher than that of Si control sample.
