Dual work function metal gate CMOS using CVD metal electrodes

Dual workfunction metal gated MOSFETs with CVD TaSiN, W and Re have been fabricated on HfO₂. T_inv as low as 1.46 nm with appropriate Vts and sub-threshold slopes 90 mV/decade or better have been achieved. For the first time we report low damage CVD processes for achieving dual workfunction metal gates in contrast to most reports in literature. Excellent hole mobility has been obtained for aggressive stacks. It is further observed that electron mobility optimization is critically dependent on specific electrode and interface layer combinations along with post deposition processing even for nominally identical HfO₂ layers.