Characteristics of dual polymetal (W/WNx/poly-Si) gate complementary metaloxide semiconductor for 0.1 mu m dynamic random access memory technology

We developed a dual polymetal (W/WNx/poly-Si) gate complementary metal oxid e semiconductor (MOS) down to a 0.15 mu m gate length. The short-channel ef fects are effectively suppressed and a saturation current of 300 mu A/mu m is obtained for nMOS and 110 mu A/mu m is observed for pMOS at a 0.15 mu m 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 p enetration is not observed with pure SiO2 gate dielectrics. The gate induce d drain leakage current could be markedly reduced by optimizing the well do ping below the gate edge.