The impact of nitrogen profile engineering on ultrathin nitridedoxide films for dual-gate CMOS ULSI

摘要

We studied nitrogen profile engineering to make an ultra-thinsilicon nitrided oxide (SiNO) film for 0.25 μm dual-gate CMOS deviceapplications. It was found that high concentration nitrogen atoms piledup near the polysilicon/dielectric interface in the SiNO film caneffectively prevent boron diffusion from the p+ gateelectrode into the dielectric film, and consequently more than 3 timescharge-to-breakdown (Q_bd) improvement can be achieved. TheSiNO film enables surface channel PMOS and can reduce the minimum gatedielectric thickness by 1.5 nm