Characteristics of Dual Polymetal (W/WNx/Poly-Si) Gate Complementary Metal Oxide Semiconductor for 0.1 µm Dynamic Random Access Memory Technology

We developed a dual polymetal (W/WNx/poly-Si) gate complementary metal oxide semiconductor (MOS) down to a 0.15 µm gate length. The short-channel effects are effectively suppressed and a saturation current of 300 µA/µm is obtained for nMOS and 110 µA/µm is observed for pMOS at a 0.15 µm gate length. The lower saturation current of pMOS is attributed both to the p + -doped poly gate depletion and to the hole mobility degradation due to the increased vertical electric field in the surface-channel pMOS. Boron penetration is not observed with pure SiO 2 gate dielectrics. The gate induced drain leakage current could be markedly reduced by optimizing the well doping below the gate edge.